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GM will use the small, turbocharged Ecotec in the Saturn Astra

Mid-sized vehicles like the Chevy Malibu are also a prime candidate for turbocharged 4-cylinder engines
GM to increase its use of smaller, turbocharged engines to improve fuel economy

In early January, DailyTech reported that Ford will use turbocharging to improve the fuel efficiency of its vehicles. The company plans to use turbocharged "EcoBoost" four-cylinder and six-cylinder engines in everything from economy cars to luxury crossover utility vehicles (CUVs).

GM has fuel efficiency on the brain as well thanks to the latest CAFE regulations and will bring a small, 1.4 four cylinder to the U.S. market. The new turbo engine will be called the 1.4 Twinport Ecotec.

The European-market engine in its naturally-aspirated form produces 90 HP and 92 lb-ft of torque. This in turn is good for roughly 38.5 MPG combined -- for comparison, a Chevy Cobalt using a 2.2 liter four-cylinder engine only achieves 28.5 MPG combined.

Adding a turbo boosts the horsepower to 140 HP with a minimal impact on fuel economy.

"You're going to see turbocharged four-cylinders in vehicles that no one could have ever imagined that they would be in," said GM engineering chief Jim Queen.

Current candidates for the new engine include compact vehicles like the Chevy Cobalt and Saturn Astra and mid-sized vehicles like the Chevy Malibu and Saturn Aura.

GM is no stranger to turbocharged engines. The company offers a wide variety of turbocharged gasoline and diesels in Europe where fuel prices are astronomical. The company also offers a turbocharged diesel in the United States in the form of the heavy duty Duramax engine used in full-sized pickups.

GM's other turbocharged motors in the U.S. see limited duty in performance models from Pontiac and Chevy as well as GM's oft-overlooked Saab brand. The turbo Ecotec four-banger used in the Pontiac Solstice GXP and Saturn Sky Red Line produces 260 HP and 260-lb-ft of torque from just 2.0 liters of displacement.

According to GM product czar Bob Lutz, the move to bring engines to the U.S. that Europeans have enjoyed for years has more to do with CAFE than consumer demand. "Europeans, at their fuel prices, are willing to pay premium prices for premium small cars that deliver terrific fuel economy," said Lutz. "That is not the case here in America, land of the big truck, big horse and the big American."

It remains to be seen how Americans will take to the turbocharged engines which will add anywhere from $250 to $450 to the purchase price of a vehicle.

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just $250
By ikkeman on 1/28/2008 8:32:22 PM , Rating: 2
28.5 mpg @ $3/gallon = $0.105/mile
38.5 mpg @ $3/gallon = $0.078/mile

the delta is about 2.7c! thats almost 10000 miles before the $250 investment is earned back - will it save anything (in money terms) over the lifetime of the car, including maintenance and such?




RE: just $250
By Brandon Hill (blog) on 1/28/2008 8:36:14 PM , Rating: 5
I haven't checked your numbers, but if they are indeed correct, I would make my money back in less than a year. I drive roughly 16,000 miles a year.

That's a quicker payback than a hybrid powertrain as well.


RE: just $250
By masher2 (blog) on 1/28/2008 8:42:36 PM , Rating: 2
I'm curious where that "$250-$450" figure comes from. I'd think the turbo alone would cost more than that, not to mention the additional cost of an engine built to withstand the higher temps and pressures.


RE: just $250
By Goty on 1/28/2008 8:50:58 PM , Rating: 3
An aftermarket turbo might cost quite a bit for an individual, but if you consider the volume these would be bought/produced in, the price would certainly decrease per unit.


RE: just $250
By masher2 (blog) on 1/28/2008 8:54:01 PM , Rating: 2
Certainly true. However, automakers that offer a turbocharged version of a car usually offer it at anywhere from $4K-$15K (or more, for a performance sports car) more than the stock version.

Obviously, there's a higher profit margin on those cars, but still a turbocharger + more strongly built engine + additional warranty service costs, all for $250?


RE: just $250
By shabby on 1/28/2008 8:56:41 PM , Rating: 2
I wish my gxp was $250 more than the base solstice...


RE: just $250
By Spuke on 1/29/2008 11:35:54 AM , Rating: 2
With the Solstice GXP (I have one too), you can't compare base prices with the "base" car directly. You have to compare equally equipped cars. There's more to the base MSRP of the Solstice GXP than just the turbo engine.


RE: just $250
By Brandon Hill (blog) on 1/28/2008 9:06:32 PM , Rating: 3
I understand where you're coming from, but remember that turbos as used today in U.S. market vehicles are geared for performance and not economy. VAG's 2.0T, GM's Ecotec 2.0 in the Solstice GXP/Sky Redline, BMW's 3.0 liter inline-6 turbo and new V8 turbo.

Here, you have a much smaller 1.4 liter engine taking the place of a 2.2 liter or 2.4 liter Ecotec in GM vehicles.

I may be talking out of my ass here, but I'd take a gander that it's much cheaper to make a relatively low-powered, fuel-efficient turbo motor than a highly-stressed, high-strung, high-performance turbo motor.

As for price premiums

Pontiac Solstice: $22,165
Pontiac Solstice GXP (turbo): $27,845

BMW 328i: $32,400
BMW 335i (turbo): $38,900


RE: just $250
By masher2 (blog) on 1/28/2008 9:12:43 PM , Rating: 2
I'm not disputing the figure, I'm really just asking from where it came. Did GM quote that differential, or is it just an estimate on your part?


RE: just $250
By Brandon Hill (blog) on 1/28/2008 9:15:57 PM , Rating: 2
Ohh, the numbers are from a Detroit automotive analyst in the source article.


RE: just $250
By shabby on 1/28/2008 9:29:59 PM , Rating: 2
Automotive analyst? Thats probably are reliable as fudzilla.


RE: just $250
By headbox on 1/28/2008 10:31:21 PM , Rating: 2
I agree- if the price isn't coming from GM or Ford, it's just wishful thinking.

Now let's look at modern motorcycles, like a stock Honda CBR that gets 160+ hp out of a 1.0 liter engine, or 120 hp out of a 600cc (0.6 liter) engine. Why can't this same technology carry over to automobiles? There are no turbos, just good design.


RE: just $250
By shabby on 1/28/2008 10:37:27 PM , Rating: 2
Lack of torque and a 13,000rpm redline will make the average consumer's ears pop.


RE: just $250
By napalmjack on 1/29/2008 8:27:21 AM , Rating: 2
Not to mention how little mass these motorcycle engines have to propel...


RE: just $250
By Brandon Hill (blog) on 1/28/2008 10:37:44 PM , Rating: 2
You have to rev the hell out of motorcycle engines to get power and what about torque?

I don't really think you can compare the two when it comes to design and power delivery.


RE: just $250
By Pneumothorax on 1/28/2008 10:41:51 PM , Rating: 3
Uhh... Have you looked at the horsepower and torque peaks of a sportbike motorcycle engine? They're pretty much low power until you wind them up over 10,000 rpms! Motorcycles make up for the low displacement by winding up the engine, no to mention their mpg isn't that great if you keep the revs up. I don't think soccer mom is going to like cruising on the freeway at 8000 rpm...


RE: just $250
By initialised on 2/6/2008 4:49:29 PM , Rating: 2
That's the problem with turbocharging a low capacity engine unless they plan to use variable geometry turbos these turboed 1.4l units could be very rev hungry.

On the other side of the equation I drove took a test drive in a 2.0T (175bhp) Vectra and was impressed and if you care to investigate turboed GMs try http://www.vauxhall.co.uk/vx/vxr/flash/index.html


RE: just $250
By Silverel on 1/29/2008 12:41:07 PM , Rating: 1
quote:
by headbox on January 28, 2008 at 10:31 PM

I agree- if the price isn't coming from GM or Ford, it's just wishful thinking.


Ehh, I dunno about that. I work in a quality department and deal with the big 3 all the time. Honestly, most of the engineers have no idea, everything is really just a shit in the dark around here. Parts could run for months being 100% out of spec, and end up getting approved, then changing the spec to meet it.

I wouldn't trust mileage estimates coming from this same group.


RE: just $250
By jtemplin on 1/28/2008 10:47:54 PM , Rating: 5
All your grammar are belong to us.
quote:
Thats probably are reliable as fudzilla.

You have no chance to survive.
Make your time.


RE: just $250
By pomaikai on 1/29/2008 12:55:47 AM , Rating: 3
The price differential is probably a 1.4L turbo vs a 2.0Liter non-turbo. The 1.4Liter is cheaper to produce, and when you add a turbo onto it it doesnt come out much more expensive than a larger engine.

With a turbo BMW you are using the same engine and just adding power. Now reduce the BMW engine to a 4banger and add a turbo so that the 4 cylinder is as powerful as the non turbo V6 and that is the comparison they are making of $450 difference.


RE: just $250
By Hoser McMoose on 1/29/2008 2:05:46 AM , Rating: 2
A good point of comparison are some slightly older VWs, like the 2004 Jetta.

That vehicle was available with either a 1.8L I4 turbo or a 2.8L V6 with otherwise identical trim levels. The performance of these two engines was in the same ballpark (200hp/195ft-lb torque for the V6 vs. 180hp/173ft-lb torque on the turbo 4, with the turbo being a tiny bit lighter). Cost difference (MSRP) between the two was $590 more for the turbo.

In terms of fuel economy, the two vehicles were rated the same (19/27mpg) when mated to the same 6-speed manual. With a 5-speed manual the turbo I4 was bumped up to 21/28mpg.

Long story short, in this example at least the case for a smaller turbo vs. larger NA engine isn't particularly strong. Hopefully GM is able to do a bit better.


RE: just $250
By Lord 666 on 1/29/2008 4:25:24 AM , Rating: 3
On paper, the numbers were similar, but actually driving them the VR6 was more enjoyable imho

When the 2.0 TDI comes out in US, it will post similar performance numbers to the old VR6, but average high 40mpg.


RE: just $250
By themadmilkman on 1/29/2008 2:44:53 AM , Rating: 2
quote:
Now reduce the BMW engine to a 4banger and add a turbo so that the 4 cylinder is as powerful as the non turbo V6...


Yes please.


RE: just $250
By Spuke on 1/29/2008 3:27:19 PM , Rating: 2
BMW could build a 4 cyl that got the same hp/torque numbers as their 6 cyl but that power would happen at a higher rpm. Although the owners aren't used to the low rpm torque that their 6 cyl turbo provides, if you took it away, they'd probably complain.

Also, BMW's are premium cars here in the U.S. and 6 cyl engines are their forte (not to mention they're expected) so to replace that engine with a perceived lesser one is a sure way to lose sales. Also, they've tried and failed to introduce 4 cyl in the past. It doesn't work in this market.


RE: just $250
By Sulphademus on 1/29/2008 9:30:08 AM , Rating: 2
FYI, BMW uses a magnesium-aluminum alloy for their normal 3.0L engine (with sleeved cylinders). The turbo is all aluminum.

Getting rid of iron blocks would make a difference as well. BMW's new 4L V8 M3 engine, aluminum block, weighs in under their former 3.2L I6, iron block.

Owning a BMW 4 banger, I believe that 140hp is fine for most sedan drivers. Point A to Point B people should be well taken care of by power/weight in about the 1hp/15lb range. These days your mainstream Accord has more horses than most sports cars of 10 years ago.

On a personal note about boosting I4's. I supercharged mine from a stock 138 to a claimed 210. Much quicker car and overall MPG dropped from 29 to 27. 50% more power (@WOT) for 7% worse fuel consumption (average) has been well worth it.


RE: just $250
By theapparition on 1/30/2008 1:20:53 PM , Rating: 2
I fail to realize why a 1.4L would be be cheaper to produce than the 2.0L. Just because it's bigger doesn't mean anything. Actual material (metal) cost asside, which is minor, there's not much difference.

A block has to be cast, cylinders and port surfaces machined, crank installed and oil pan added. A head with gaskets installed, each head with springs, valves, etc. Intake and exhaust manifolds both. Sorry, just don't see where the 1.4L example could be that signifigantly cheaper than the 2.0L.

Yes, the 2.0L would be a little pysically larger, but a larger displacement engine also means that it has larger holes. It's the holes (cylinders) that add up to equate to displacement, so I'd wager that overall raw material usage may even break even. I just don't see how, all other features equal, that a somewhat larger engine costs more to manufacture.

Now take all the added features that may be required to enusre long term operation of that same engine with a turbo. That can far outweigh any minor cost differntial. Add the cost of turbos, and it gets even more out of control.

Sorry, don't see that $450 price differnce.


RE: just $250
By Spuke on 1/30/2008 11:56:05 PM , Rating: 2
I think I agree with you that the cost to develop and build a 1.4L won't be much less than building a 2.0L. They're using a 1.4L because it will be more fuel efficient off boost than a normally aspirated 2.0L with the same hp. Off boost is where these engines will spend most of their time. If people want the full 140 hp then they'll tip into the gas a bit. If GM uses direct injection along with the turbocharging, then the moments that people do use all 140 hp will not affect fuel mileage much if at all. I have a direct injection 4 cyl turbo car and the worst mileage I've gotten was 24 and that was having some fun (ok, it was a LOT of fun) in all city driving.


RE: just $250
By stonemetal on 1/29/2008 8:35:58 AM , Rating: 2
Yeah but there is more different on them than just turbo. Look at Scion tc for the same car with the only difference being dealer installed supercharger under warranty only about 3K difference.


RE: just $250
By Drexial on 1/30/2008 11:17:34 AM , Rating: 2
These are being put in place for efficiency not pushing power. The stock bottom ends on many cars can take an extra 100-150 HP with out problems, these turbos will probably only be boosting about 50 at most. They aren't there to beat up the engine the aid a bit.

Also when you consider boosted cars there are also, suspension, racing seats, lightweight parts, carbon work, more aluminum parts, light weight wheels and more expensive tires. so its not the turbo adding in the cost as much as you seem to think.

Not only are the cars not getting the rest of those upgrades, the turbos them selves aren't going to be made to push 400 HP, so they will be able to make them cheaper as well. Probably only pushing like 2 PSI. which doesn't seem like much. But a lot of tuned cars are only pushing 10psi.

so $250-$450 seems perfectly reasonable. Id bet at least 10% of that is profit mark up.


RE: just $250
By theapparition on 1/30/2008 1:21:37 PM , Rating: 2
I agree, something is not right with the numbers.


RE: just $250
By Spuke on 1/29/2008 11:46:28 AM , Rating: 2
quote:
I'd think the turbo alone would cost more than that, not to mention the additional cost of an engine built to withstand the higher temps and pressures.
Turbochargers don't cost OEM's very much at all. The size of the turbo in a 1.4L engine would be very small and extremely cheap (my guess would be less than $200 for an OEM). Also, you're going to put pistons and rods in an engine anyways so there's no cost there and at the roughly 140hp that the article is stating, the engine could be designed with the exact same specs as the normally aspirated one and still be extremely reliable (maybe even more so with direct injection).


RE: just $250
By Arribajuan on 1/29/2008 11:38:06 AM , Rating: 2
I think the whole turbo / inter cooler / etc will cost more than 250, of course it is a smaller engine.

1 - The whole thing is that it will be more efficient. Enviromentalists will be happy.

2 - The USA will be less dependent on foreign oil which is a hot topic.

3 - It is not to give consumers a "better" choice. Companies are forced to do this because of the 2020 35 m/g requirement.

4 - Your numbers are at 3 dollars / gallon. Imagine at $5/g


RE: just $250
By Eris23007 on 1/29/2008 3:23:18 PM , Rating: 4
I dunno, sometimes I wonder if enviros won't be happy until the end of western civilization.

All kidding aside, I don't think enviros will be satisfied by a few higher MPGs, even across all cars. Going to take the end of the internal combustion engine to achieve that...


RE: just $250
By DigitalFreak on 1/28/2008 8:46:45 PM , Rating: 2
Wouldn't having a turbo also require you to burn premium gas? That's another $.20/gallon.


RE: just $250
By herrdoktor330 on 1/28/2008 8:52:02 PM , Rating: 2
Not true at all.

If the compression ratios of the engines are at 10:1 or higher, then yes. Premium fuel will be required. But as long as engine compression ratio stays around the 9:1 or a little lower, then everything will be fine.

The only cars that really needs premium fuels are ones with higher compression. But you're not going to want to use high compression in turbo applications anyway.


RE: just $250
By Brandon Hill (blog) on 1/28/2008 8:56:04 PM , Rating: 3
A 2008 Subaru Impreza WRX has a compression ratio of 8.4:1 and still requires premium.


RE: just $250
By masher2 (blog) on 1/28/2008 9:05:09 PM , Rating: 2
The compression ratio of a car is calculated at 1 atmosphere. A turbocharger forces more air into the cylinder, resulting in a higher effective compression ratio and a much higher tendency for premature detonation.


RE: just $250
By herrdoktor330 on 1/28/2008 10:58:05 PM , Rating: 2
Very true... but you can still dome out the piston far enough to allow for regular gas. Or you could just use smaller levels of boost. A 8 psi boost would be what I would think is the "sweet spot" for optimal boost for a quick spooling, modest horsepower gain.

I wouldn't think they'd be trying to apply the same level of boost to your "economy" car that they would in a "sports level" car that a WRX STI or Acura would have. But then again, I could be wrong.


RE: just $250
By Polynikes on 1/28/2008 9:33:45 PM , Rating: 2
Requires? My Nissan Sentra fuel tank has a sticker suggesting I use premium fuel, along with pretty much every other car in production now, probably. I find it hard to believe a WRX requires premium fuel.


RE: just $250
By Andrwken on 1/28/2008 10:08:20 PM , Rating: 2
On the contrary, once the price of gasoline made its way into the $2.50 range, a lot of cars were "redesigned" to run on regular (see most of cadillac's lineup in the last few years). From what I picked up, it didn't require any mechanical changes, just some tuning in the controls. I don't think many manufacturers will recommend it when your consumer can be so driven by the price of the fuel.

Also, 10.5:1 was usually the number to start using higher octane fuels. But if you are one of the guys that runs racing fuel for the air cleaner and exhuast you added, you can actually lose power due to the fact that higher octane really only retards the ignition timing to avoid preignition ("pinging"). Most modern electrical systems can only advance the spark so far and usually don't compensate well for racing fuel, which results in a poor burn and loss of power. From a gearheads perspective, premium fuel is folly for just about any street car out there.


RE: just $250
By WhiteBoyFunk on 1/31/2008 5:40:49 PM , Rating: 2
This is not totally accurate. I'm not contesting the part about corporations reinventing the wheel to allow for lower octane ratings.

I am, however, contesting the commonfolk talk about octane ratings.

quote:
From a gearheads perspective, premium fuel is folly for just about any street car out there.


A higher octane rating is NOT pointless. Higher octane rated fuels can withstand higher temperatures and pressures before spontaneously combusting. In the case of high-compression engines this is critical because it prevents preignition, knocking, or detonation (all the same thing) which is basically an explosion in the chamber before the spark and the top of the compression stroke. That will take place if too much pressure is applied to a low octane fuel.

In the case of low compression turbo engines like Fairlady Zs, it's even more important. The engine itself runs at 8.2:1 or so which is fairly low, but introducing massive amounts of oxygen and fuel into the cylinders is a recipe for disaster if you use something like 83 octane in them. Count on at least one holy piston and spun bearings across the crank.


RE: just $250
By FITCamaro on 1/28/08, Rating: 0
RE: just $250
By masher2 (blog) on 1/28/2008 10:21:04 PM , Rating: 2
> "Yes it requires premium. If you put 87 or 89 in the tank, you will likely damage your engine"

It's rarely so simple. As said earlier, modern fuel management systems detect knock, and can retard timing accordingly. Of course, if it retards it severely, that's going to move you into a much less efficient portion of the engine's stoichiometric map, which is going to cost you a lot more in fuel than what you'll save from skipping the premium.

It's a complex subject though, and there are many factors besides the engine itself. Current temperature, humidity, and even altitude (air pressure) all play a part. If you live in a low-lying hot, dry state, you'll need a higher octane fuel than someone in a high, cool, location.


RE: just $250
By Andrwken on 1/28/2008 10:36:58 PM , Rating: 5
That's very true. Go drag racing during the day when its 80 and humid, and then make the same pass at night when its 65 and dry. You can get a substantial increase in your 1/4 mile times. Which is why a lot of bracket racers will keep barometer and thermometers at the track with them.

Also, think about these turbocharged cars from the manufacturers point of view. Will premium give them a slight performance increase for advertising, yes. But would they actually trust you with their new car, under their warranty, to only run 93 octane in it? Yeah, right. They will cover their ass and make sure it can run the lowest octane at the pump to avoid unnecessary warranty work.


RE: just $250
By Regs on 1/29/2008 8:37:25 AM , Rating: 2
I'd imagine this is mostly because cooler air is denser fro combustion.


RE: just $250
By werepossum on 1/29/2008 3:16:41 PM , Rating: 2
quote:
I'd imagine this is mostly because cooler air is denser fro combustion.


True. An old drag racing trick is to fill an emmissions cannister or similar container with ice and loop several feet of fuel line through it, thereby chilling your fuel-air mixture and making it more dense (more powerful per unit volume.) A similar trick is to provide a ram air system to bring in relatively cool combustion air from the front of the vehicle as opposed to heated air from the engine compartment. In fact, I'd say most cars built today draw combustion air from outside the engine compartment for this reason.


RE: just $250
By theapparition on 1/30/2008 1:26:57 PM , Rating: 2
quote:
In fact, I'd say most cars built today draw combustion air from outside the engine compartment for this reason.

Sadly, almost no regular production vehicules feature true "cold air" intakes as standard equipment.


RE: just $250
By protest the hero on 1/28/2008 10:16:21 PM , Rating: 2
I wouldn't say a natural aspiration engine would require premium fuel, but there are cars that definitely do.

Forced induction has a tendency to ignite pre-maturely because the air is being compressed much higher than normal intake, thus getting much much hotter. To prevent this, the engine pulls back on the timing, called Knock Retard(what a name) or KR.

Most performance part vendors will explain to the car owner that a package of mods should be installed before adding more boost, to make sure that everything is working on the level. Higher octane fuel (that is, not necessarily 'racing' fuel, but at least 92+) is a start, as well as good air intake flow, quality headers, and any number of other things.


RE: just $250
By Zoomer on 1/28/2008 10:36:44 PM , Rating: 1
In some places, 92 octane fuel is regular, 95 is mid-grade, and 98 octane is premium.

Hmm.


RE: just $250
By Hoser McMoose on 1/29/2008 12:34:02 AM , Rating: 5
In some places (Europe) they measure octane using the RON value. In other places (North America) they measure octane using the Anti-Knock Index (RON/2 + MON/2).

This is why you see the difference.

92-octane RON in Europe ~= 87 AKI in North America.


RE: just $250
By sprockkets on 1/28/2008 10:52:09 PM , Rating: 2
Acura TSX requires it. Some say in the manual, such as the Mazda 2.3 turbo engine, that you can get away only temporarily with 89, but needs at least 91. And when it gets 89 octane gas, the computer will change the spark timing to compensate, hence less performance.

In any case, increasing the pressure of what is injected to an engine requires an increase in fuel to compensate.

Actually, a very easy way of saving fuel is to remove the outside mirrors and use cameras instead, with displays on the sides, which reduces drag significantly.

Look, there is a much easier way of getting more MPG, and that is driving vehicles like the rest of the world. The current trend of using full size SUVs to cart around 95% one person to work is overkill.


RE: just $250
By cleco on 1/29/2008 9:34:08 AM , Rating: 3
Yes it is required. If a car manufacturer says premium it is most likely they tuned the fuel maps for that octane level.

And for a turbo car.... why wouldn't you put premium in there?????

Btw Sentra isn't a sports car... now if you had a SE-R Spec V then maybe you could compare it to a WRX. Even then the Spec V is an overpriced 16 sec 1/4 mile sports car


RE: just $250
By KamiXkaze on 1/29/2008 9:22:05 PM , Rating: 2
So the Nissan Altima 3.5se sedan or coupe.

KxK


RE: just $250
By tjr508 on 1/29/2008 8:00:09 AM , Rating: 3
The WRX bost manifold pressure up >10psi. We're talking 4-5 here, not 10-15.


RE: just $250
By joex444 on 1/28/2008 8:53:17 PM , Rating: 2
Agreed. Let's say regular is $3.00, and premium is $3.20 (my area is $3.00 for premium, $2.81 for regular, but when the market recovers we'll go back to the higher prices).

I figured it's at 11,288 miles you will recover the cost of a $250 increase and 20,319 miles until you recover a $450 increase.

Essentially we're not talking about much though. If you refuse to pay $250 for a turbo, you also probably refuse to put new tires on the car, change the brakes, fix a radiator, put in a new battery, fix an exhaust problem, or any of the other numerous simple repairs which can cost several hundred dollars.

The *REAL* question: can you get that in a manual, and will it be cheaper than the non-turbo automatic? I'd call that a win-win-win-win.


RE: just $250
By Zoomer on 1/28/2008 10:38:01 PM , Rating: 1
It's called a used car. ;)


RE: just $250
By shabby on 1/28/2008 8:55:31 PM , Rating: 2
Normally yes, however im sure gm would adjust it to run on 87 octane. All turbo cars can run on 87 octane, its just that the power output is a bit lower.
It would be kind of idiotic of gm to use a fuel efficient engine that gets more mpg then all other cars but needs premium fuel.


RE: just $250
By masher2 (blog) on 1/28/2008 9:07:44 PM , Rating: 4
> "All turbo cars can run on 87 octane"

All? No. Most can run on 87 octane simply by retarding the ignition timing...but that's going to affect not only performance, but mileage.

And for those few (mostly older vehicles) which can't, predetonation can cause not only severe knocking, but serious engine damage.


RE: just $250
By Haltech on 1/28/2008 9:17:05 PM , Rating: 2
along with a horrible idle all before the break happens


RE: just $250
By shabby on 1/28/2008 9:26:33 PM , Rating: 2
All new ones at least, as for the old ones they still had knock sensors which would retard the timing on low octane fuel. Maybe the rx7 was the oddball...


RE: just $250
By Sulphademus on 1/29/2008 11:16:51 AM , Rating: 2
Rotary Engine = Oddball.


RE: just $250
By FITCamaro on 1/28/2008 10:11:38 PM , Rating: 2
Uh...try again. A turbo increases the compression in the chamber. To prevent pre-detonation, you need a higher octane fuel. Know something about cars before you open your damn mouth.

Now yes, with some timing control, you can get it to run, but you're going to lose power and efficiency.

I dare you though to go buy a Subaru WRX and put 87 octane in it. Besides, premium vs. regular adds a dollar or two to the cost of a tank. I have never owned a car that didn't require premium.


RE: just $250
By Andrwken on 1/28/2008 10:25:11 PM , Rating: 2
As an owner of a number of turbocharged cars in the past and current saab 9-3 ss owner, yes it runs fine on 87 octane. There is minimal to no gain in running premium. Most modern ignition systems retard and advance spark enough to compensate just fine for the little difference in octane. Unless your compression is so radical it causes massive preignition on low octane, but that's usually on aftermarket installed turbos and not the ones from the factory that have the compression stroke neutered to compensate for increased volume of turbocharging.

Fit, I find it hard to believe you have found enough GM vehicles in your time that "require" premium. My supercharged pontiac grand prix did not "require" it. Most of GM's cars have always been regular fuel. Even the beretta GTZ I had with the high output quad 4 at 10.5:1 was "premium recommended" and not required.


RE: just $250
By masher2 (blog) on 1/28/2008 10:37:14 PM , Rating: 2
It's possible that both of you are right. The octane requirement of an engine isn't a fixed parameter, it varies, sometimes quite dramatically, based on local conditions. A simple change from 100% humidity to 0% can affect required octane by up to 6 points. Ambient temperature and air pressure affect it as well.


RE: just $250
By Andrwken on 1/28/2008 10:47:10 PM , Rating: 2
Very true, but don't you think the exreme variables have been calculated and accounted for. With the way manufacturers "cover their ass" to avoid costly recalls, I highly doubt any large automobile manufacturer hasn't at least taken that into account when tuning the ignition and electrical systems. I live in Wisconsin, and I drive turbocharged cars. I don't really have any problem and with the weather variance we have around here, it really hasn't affected the mileage or the performance. Although, leaving it run for 15 minutes to warm it up and get my seat heater toasty sure does kill my mileage. lol


RE: just $250
By FITCamaro on 1/28/2008 11:45:07 PM , Rating: 3
While Wisconsin gets cold and could cause cold start issues, the weather there is perfect for engines. Nice cold, dense air, decent humidity. You have to worry more in extremely hot, dry places. Especially with turbo-charged engines. If anything in your area, you're going to get better mileage and performance once its warmed up and at nominal operating temp. Cooler, denser air = better mileage and more horsepower.


RE: just $250
By Andrwken on 1/29/2008 6:45:16 AM , Rating: 2
we run well into the 90's up here in the summer, and vary from no humidity to high humidity. the point was that you can't vary your range of temps and humidity much more than up here. take yesterday for example. It was 45 degrees and sunny. The day before, it was 10. The summers are the same. One day it will be 90 and humid. That evening, you'll get 65 and no humidity. I don't hear my turbocharged car start knocking in the evening. They are designed to run in a lot wider range of situations then people give them credit for. Will I lose a 10th on my 1/4 mile time without the 93 octane, maybe. But does the average person even notice that?


RE: just $250
By masher2 (blog) on 1/29/2008 10:25:37 AM , Rating: 3
It's a little more effect than that. Looking at a stochio map for my 3.5V6, it loses about 3 hp per degree of timing retard.

Under worst-case conditions, 87 might cause it to retard some 10 degrees. That's 30 hp on a 300 hp engine...and probably about a 10% loss in fuel efficiency as well.


RE: just $250
By Andrwken on 1/29/2008 2:42:49 PM , Rating: 2
That may be true, but from most real world tests I have seen, the number is usually 10 or less hp. Although, 300 hp in a 3.5l v6 should be more susceptible to power loss than a 300 hp 5.0l v8. Even the most stringent companies claim no more than 5% loss with regular in a car designed for premium.

I found this interesting read with some good insight.

http://www.usatoday.com/money/autos/2003-07-30-pre...

One quote,

"All Porsche engines are designed for premium, too, but it's not available everywhere. "Our cars must be able to drive all over the world, and so we are able to run on regular," says Jakob Neusser, director of powertrain development at Porsche's research and development center in Weissach, Germany. "You don't have to feel that a mechanical problem or anything else will happen" using regular gas, even in the highest-performance, regular-production Porsches."


RE: just $250
By FITCamaro on 1/28/2008 11:37:07 PM , Rating: 2
My 85 V8 Camaro required premium, my 87 IROC-Z required premium (extremely noticeable difference if you put 89 in it), my 89 Camaro barely ran on premium (10.44:1 compression and was carbed so no fancy knock sensors or anything), and my 06 Cobalt SS recommends premium. Yes it'll run on lower grades but I'd rather have the extra horsepower and efficiency. I can handle paying the extra dollar.


RE: just $250
By 67STANG on 1/29/2008 12:17:44 AM , Rating: 2
The 87 Camaro IROC-Z had the horrible 305 engine with only 9.3:1 compression from the factory (not to mention a whopping 190 horsepower)... Unless you rebuilt it or replaced the stock heads, 9.3:1 can easily run on 87 Octane....

My 67 Mustang (naturally aspirated) has 10.4:1 compression and can run on 89 or 91 octane (and lots of it), without much difference in performance. No computers, unless you count MSD6AL ignition as a computer.


RE: just $250
By FITCamaro on 1/29/2008 6:45:50 AM , Rating: 3
While I did have the 305TPI engine, 350s were also available.

And fuel injection wasn't as advanced then as it is now. They didn't have knock sensors and what not.

Yes depending on how an engine is built and where you set your timing, you can get a higher compression engine to run on lower grade gas. Again though, I can afford to pay the dollar difference so I don't even think twice about putting premium in my car if it calls for it.


RE: just $250
By masher2 (blog) on 1/29/2008 5:29:04 PM , Rating: 1
> "Again though, I can afford to pay the dollar difference..."

Premium is $0.30 more a gallon here than regular in most stations. On a 20 gallon tank, that's $6.

A couple stations are still only charging the standard 20 cent markup, but at least one floated a 40 cent surcharge for premium. I'm sure as consumers adapt to the higher prices, you'll see premium stay a constant 10% price differental.


RE: just $250
By pomaikai on 1/29/2008 1:07:22 AM , Rating: 2
Those camaro engines are old and dont have the technology the newer ones did. It is much easier now days to extract more horsepower without requiring premium. My 5.7L 380HP Toyota Tundra uses regular.


RE: just $250
By Andrwken on 1/29/2008 7:13:06 AM , Rating: 2
Some people can notice that. I have even hear some people claim they feel a difference when they put new synthetic oil in (not sure about this one). Those carbed camaro's were definitely sensitive to fuel quality (good ol' quadrajunk, I mean quadrajet carbs) ;) As far as the compression goes, no f-body was over 9.5:1 in the 80's.

http://www.f-body.org/tech/tech.htm

If you feel it, and you need it, by all means use it. I'm not trying to tell you how to handle your ride. But with the amount of time I spent around cars growing up (father ran an engine/transmission shop, and raced NHRA) the discussions about premium in street cars came up a lot. That cobalt probably can feel a bit snappier with the premium (small displacement with supercharger). My Saab is the linear so its only the 175 hp turbo, not the high output. If I spend the 800 bucks for the ecm mod, I will get the high output specs (210bhp), and the fussier fuel requirement (will probably only see the full 207hp on 87). The point is, that saab motor is the same 2.0 ecotec that is in your cobalt. They make no physical changes to get the extra 35 hp, but yet they upgrade the fuel requirement to "premium recommended". That is purely for the max Hp output that can be obtained and not because the motor now can't run on 87 without pinging. The fuel and electrical systems do a pretty good job of eliminating this nowadays.


RE: just $250
By Spivonious on 1/29/2008 9:26:22 AM , Rating: 2
Yeah, I notice the engine running more smoothly right after an oil change.

I haven't tried putting anything higher than 87 fuel in my car though, since the manual clearly states that the engine was designed to run with 87. Back when I had my toy truck and premium gas was under $1 a gallon, I would put it in just for kicks and never noticed a difference.


RE: just $250
By EricMartello on 1/30/2008 10:13:30 PM , Rating: 2
Quick fact about octane rating and your engine:

You will always get the best performance and efficiency from your engine by running the LOWEST octane you can, without your engine knocking.

If your car was designed for regular 87 octane, you DEGRADE performance by putting in anything higher. People has the misconception that higher octane means more power, somehow.

The octane number is a rating of the fuel's resistance to detonation (combustion by compression). Higher octane numbers simply mean the fuel will detonate at higher pressures, i.e. higher engine compression ratios.


RE: just $250
By theapparition on 1/30/2008 1:33:56 PM , Rating: 2
Awesome.........

The f-body.org site quoted here on daily tech!

I'd never thought I'd see the day. Spent too much of my life there, and loved every minute.

Cheers!


RE: just $250
By DukeP on 1/29/2008 1:47:29 AM , Rating: 1
In Europe the lowest quality of gasoline available at the pumps are 92. Most cars use 95 octane.

So at least over here, its a non-issue.

~~DukeP~~


RE: just $250
By nothingtoseehere on 1/29/2008 2:11:45 AM , Rating: 2
As is mentioned above, octane levels are measured differently on the two sides of the ocean.


RE: just $250
By Spuke on 1/29/2008 11:51:18 AM , Rating: 2
quote:
Wouldn't having a turbo also require you to burn premium gas? That's another $.20/gallon.
Not necessarily but with direct injection you definitely don't have to. Even GM states that the Solstice GXP/Sky Redline can be run on 87 octane but at reduced power levels. I'd imagine a DI turbo 1.4 making only 140 hp would no issues with 87 octane and I wouldn't be surprised if GM tunes the motor to run on 87.


RE: just $250
By RU482 on 1/29/2008 11:58:01 AM , Rating: 3
cough...E85...cough


RE: just $250
By ChristopherO on 1/28/2008 8:56:29 PM , Rating: 2
Your stats also don't take into account that turbos are best served with premium fuel... Heat is the enemy of turbos and will significantly shorten their life. You can cut 10-25% off the life of a turbo by using a lower grade fuel. That's a bit of a simplification, it also depends if your turbo is intercooled, water cooled, oil cooled, etc.

Depending how someone drives, they can probably get 90-140k from a turbo before it needs replacement. The turbo replacement will probably run somewhere between $800-2,000 (parts + tax + labor) depending on the size of the unit.


RE: just $250
By Andrwken on 1/28/2008 10:30:10 PM , Rating: 2
Oil lubrication and water cooling from the existing systems of the car have really added to the reliability of turbos and you do tend to see a lot more miles out of the turbocharger than you used to. Very reliable nowadays compared to say, the 80's.


RE: just $250
By ChristopherO on 1/28/2008 11:15:48 PM , Rating: 2
True, but more than likely, the second owner of a lot of those vehicles is going to have a huge cost when the turbo fails.

They do boost fuel economy, but you have to spend it on higher grade fuel and potential turbo replacement. It's not quite accurate to consider a turbo an "overall cost savings".

The other thing is that a turbo charged engine without a turbo doesn't perform like a normally aspirated engine. The turbo is included as an integral component, so when it fails it needs to be replaced to get any significant power out of the engine. I had an old 86 Volvo 740 where the turbo failed and it was quite a unique experience behind the wheel. The car felt like I was using one of those 8hp B&S engines used on a lawn tractor.


RE: just $250
By FITCamaro on 1/28/2008 11:57:27 PM , Rating: 2
Did you actually just say a turbo boosts fuel economy?

A turbo forces more air into the combustion chamber. What else is required when you do that? More fuel. A high compression NA engine of the same size will get better fuel economy than a turbocharged one, just make less power. It's not a free trade off of more power for no extra fuel.

Now yes, a smaller turbocharged engine might get better fuel economy than a larger NA engine with the same power. But even that generally has not been the case. Take say the BMW 335i. 300hp 300tq I6 twin turbo. 17/26 mpg. Now take the 06 GTO. 6.0L V8 400 hp 400 tq. 17/25. V8 has more power, is faster, and gets the same mileage. Why? Gearing. Even the largest big block can get decent mileage (provided the cam isn't huge) if you give it the right gearing.