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Audi Q5

Audi A8
Audi A6, A8, and Q5 to get TDI power

Audi is no stranger to diesel engines. In Europe and other world markets, Audi has a number of TDI options available for consumers for the many models in its lineup. In the United States, however, those looking for a diesel Audi can only choose from the tiny A3 TDI or the mammoth Q7 TDI.

Now, according to Fourtitude, Audi is looking to spread a bit more TDI lovin' to customers in the U.S. The company just announced today that it would bring its 3.0-liter TDI engine to the A6 sedan, A8 sedan, and Q5 small crossover vehicle.

Those still holding out for a TDI engine in the popular A4 sedan and Avant will have to wait a little longer. Audi officials say that since the current A4 is already in the "advanced stages" of its lifecycle, that U.S. customers will have to wait until the next generation A4 arrives in a few years. 

The 3.0-liter TDI coming to the A6, A8, and Q5 is already available in the Q7 TDI. It generates a respectable 225hp at 3,750 rpm and a gargantuan 406 lb-ft of torque at 1,750 rpm in that application. The engine is capable of giving the 5,567-pound crossover EPA ratings of 17 mpg in the city and 25 mpg on the highway. 

The three new TDI models are much lighter which should make the fuel economy gains even more impressive compared to their gasoline engine counterparts.

There were recent reports that General Motors is looking to bring a diesel engine to the U.S. market for its Cruze compact instead of going for a fully-fledged hybrid model.



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Good.
By Motoman on 3/8/2011 2:41:06 PM , Rating: 2
I'd really like to see more fuel-efficient diesels in the States.

While it's nice to hear about this 3.0 liter motor...what about smaller cars with, say, 1.5 liter turbodiesels? I'd have to believe that with modern technology you could get good performance and good fuel efficiency for small and midsize cars to easily trump 4-stroke motors.




RE: Good.
By Dr of crap on 3/8/2011 3:13:37 PM , Rating: 2
Yea, but the money to be made is in the bigger cars and SUV.

You can call them crossovers or what ever marketing spin they use, it's still a SUV in any size and its the cash cow for now.


RE: Good.
By EJ257 on 3/8/2011 3:40:45 PM , Rating: 2
The SUV itself is the result of marketing. Those things started out as nothing more than station wagons on stilts. Now everything with 6 inches of ground clearance and a rear gate is an SUV. To call it what it is, a station wagon with high ground clearance doesn't sound "cool" enough so it won't sell hence we have the "sports utility vehicle".


RE: Good.
By Solandri on 3/8/2011 8:37:14 PM , Rating: 2
Actually, they started off as 2-door 4-wheel drive off-road vehicles. Basically a 4WD pickup truck with a shell permanently affixed over the bed. They were used primarily for hauling stuff and off-roading, which is where the "sport utility" part comes from.

The automakers added 2 more doors to make them a bit more practical when not off-road. Suddenly people who wanted the functionality of a station wagon, but didn't want a station wagon because their parents had one when they were kids, saw them as a perfect substitute. Even if they never took the things off-road and always drove them around in 2WD mode.

I agree marketing helped sustain the trend, but the start was almost an accident. I was actually looking to buy one about 2 years before the trend started. I wanted the 4WD to access some remote fishing holes, and the cargo space for carrying fishing gear (though I'd gotten remarkably adept at squeezing a 7 foot pole into a 1980s Accord). Problem was I had two buddies I usually fished with, so preferred to have doors going to the back seats. Toyota and Nissan announced they were going to have 4-door models in the following year, so I waited. And unwittingly got a front row seat to watching the whole trend unfold.


RE: Good.
By Keeir on 3/8/2011 4:23:47 PM , Rating: 2
There are a few reasons why 1.5L Diesels are not used.

#1. Maximum Power. A 1.5L Diesel would likely put out between 100-120 hp. That's B segment territory and that is not a popular area in the US. US is more likely looking at 1.8L for the C-segment (Civic) and 2.0L for the D-segment (Camry) minimums.

#2. Cost versus Fuel Savings.
Diesel versions typically get 20-25% better fuel economy than "equal" gasoline versions.

If you spend 2,500-3,000 dollars on gasoline (like a typical large car/SUV) then 25% of that is more than 25% of the 1,500-2,000 dollars that a Compact Car driving might for the same miles.


RE: Good.
By Motoman on 3/8/2011 6:32:46 PM , Rating: 2
BHP isn't as important as people tend to think it is. Torque is a lot more important. And in anything between a small car and a minivan, I'm thinking a 1.5l turbodiesel would work fine.

But make them 2.0l motors for all I care. I'm just saying for the fuel economy, if nothing else, bring us more diesels.


RE: Good.
By Spuke on 3/8/2011 6:56:22 PM , Rating: 2
Gearing is the most important. Proper gearing will make any powerplant work well.

PS - torque = 5252 x HP/rpm


RE: Good.
By Motoman on 3/8/2011 9:43:59 PM , Rating: 4
Gearing...yes and no. While proper gearing makes *almost* any engine effective, a weak motor with proper gearing that takes 30 seconds to get from 0 to 60mph isn't going to be very useful.

As for your second point...I see what you did there, but I am guessing you are twisting the math around to make torque look like a derivative of HP. It's not - HP is a derivative of torque.

Torque x RPM / 5252 = HP <-- that's the way that is normally stated.

If you play with the numbers you can see how high RPM motors can post big HP numbers but have little effective torque...and the other way around. While HP may be flashy on a dyno, torque is what really matters for the vast majority of every day applications of motoring.


RE: Good.
By Calin on 3/9/2011 2:49:09 AM , Rating: 3
Just as a side note:
HP is maximum HP of the engine, while torque is the maximum torque of the engine.
As such, a diesel engine with flat torque curve between 2000 and 4000 rpm and max power of 100HP at 4000 rpm will have 50HP available at 2000rpm.
Meanwhile, a non-turbo, typical gasoline engine of 200HP, with max power at 6000rpm and flat torque from 4000 to 6000 rpm (and, let's say, half the 4000rpm torque at 2000rpm) will give me about 133HP at 4000rpm and some 33HP at 2000rpm.
So, that 100HP turbo diesel engine will give me more power in the idle to some 3000 rpm range. If you're driving mostly in that range, and can learn the fact that revving doesn't help, diesel is good for you - it's more expensive initially.
On the other side, you really doesn't need the entire power of the engine except when forcing to pass another car/truck (but then you really really want to end the passing as fast as possible). In this case, with downshifting, that 200HP gasoline engine will really offer you power.

So, that's the idea in short - power and torque are related, but they're not the maximum values that everyone likes to give - they varies based on rpm and a diesel engine will have quite a bit of rpm range where it will soundly beat a similar gasoline engine (be it similar in displacement, maximum power, maximum torque or price). That's right, a turbo diesel 2 liter engine still has a rpm range where it's superior to a 3 liter gasoline (or turbo gasoline) engine. It all depends where you draw the line between what you NEED and what you like.


RE: Good.
By Spuke on 3/9/2011 1:34:47 PM , Rating: 2
quote:
That's right, a turbo diesel 2 liter engine still has a rpm range where it's superior to a 3 liter gasoline (or turbo gasoline) engine. It all depends where you draw the line between what you NEED and what you like.
All things being equal including HP, yes, the diesel will be quicker. But a 100hp diesel will NOT be quicker than a 150hp gas engine. no matter the difference in torque. Compare an equivalently equipped BMW 335i to a 335d. The 335i is quicker despite the 335d's 400+ lb-ft of torque. The difference, if all else is equal, is HP.

The best thing about diesels is big torque at low rpms. Great for trucks that pull/haul lots of weight. Makes for much quicker acceleration and better fuel economy under load. For cars, it's just fuel economy and the big torque down low feels good when you're driving.


RE: Good.
By Keeir on 3/9/2011 12:25:02 PM , Rating: 2
quote:
BHP isn't as important as people tend to think it is.


I guess I should explain further then.

In the US market, it seems to me that the 0-60 times should be in the 10-11 second range as a minimum. Although Torque engines produces significant power at low RPM which makes them feel very solid and strong, they are incapable of quick acceleration when "torque" matched to a car.

A quick trip to vw.co.uk, looking at the Polo B-Segment Car, the 1.2 Liter TDI takes 13.9 second to get to 62 mph. That just wouldn't be acceptable for the US market. The 1.6 Liter TDI (90 PS) takes 11.5 second, which is barely acceptable for the US market. Its true the 1.2L TDI gets 10% better fuel economy, but most US consumers are going to prefer the 1.6 Liter TDI.

Looking at the Golf C-segment car, the 1.6 TDI in a 105 PS tune takes 11.5 seconds to get to 60 versus 9.3 for the 2.0 TDI in 140 PS tune. It gets 6% better fuel economy.

So you have the choice, 35 MPG combined car that takes 9.3 seconds 0-60 or a 37 MPG combined car that takes 11.5 seconds 0-60. Americans have pretty much choosen in the past the better 0-60 time. While this preference exists, I doubt a 1.5L turbodiesel would satisfy people (versus a 2.0L or a 2.5 etc) in any other segment besides B.


RE: Good.
By Spuke on 3/9/2011 1:43:19 PM , Rating: 2
quote:
While this preference exists, I doubt a 1.5L turbodiesel would satisfy people (versus a 2.0L or a 2.5 etc) in any other segment besides B.
I don't even think it would fly in B segment as most of those cars are quicker than 11 sec. Granted 0-60 isn't everything but Americans preferences in a certain amount of acceleration can be correlated to 0-60 times which looks like what you're doing here.


RE: Good.
By Keeir on 3/10/2011 7:53:39 PM , Rating: 2
Erm... I didn't mean the VW Polo with the lower tuned 1.6 TDI engine.

A VW Polo with the higher tuned 1.6 L TDI would probably get to 0-60 in ~ 10 seconds or so US. Given that the Diesel is going to "feel" faster for normal driving than the same gasoline car, this would probably work in the US market, after all it would feel just as fast if not faster than the Prius.

I think for the US market
B- Segment, 100 Diesel HP, 120 Gasoline HP
C- Segment, 120 Diesel HP, 140 Gasoline HP
D- Segment, 150 Diesel HP, 180 Gasoline HP
Small CUV, 140 Diesel HP, 170 Gasoline HP
etc


RE: Good.
By Mr772 on 3/9/2011 6:52:50 PM , Rating: 2
I haven't seen it pointed out but durability is also a factor when talking gas vs diesel engines - diesels are more durable and last much longer than gas engines. The 7.3L Ford PSD engine is called the "800,000 mile motor" for a reason.

I have an 09 2.0L TDI Jetta Sportwagen that is a blast to drive, with a chip tune I'm turning 185hp and 293lbs torque all while getting 45+ mpg's of mixed driving 30%city/70%freeway. And I don't have a light foot, I have lots of state patrol notes to prove it.

American companies are idiots for not offering more diesel options to consumers.


RE: Good.
By Mr772 on 3/9/2011 6:56:36 PM , Rating: 2
I haven't seen it pointed out but durability is also a factor when talking gas vs diesel engines - diesels are more durable and last much longer than gas engines. The 7.3L Ford PSD engine is called the "800,000 mile motor" for a reason.

I have an 09 2.0L TDI Jetta Sportwagen that is a blast to drive, with a chip tune I'm turning 185hp and 293lbs torque all while getting 45+ mpg's of mixed driving 30%city/70%freeway. And I don't have a light foot, I have lots of state patrol notes to prove it.

American companies are idiots for not offering more diesel options to consumers.


RE: Good.
By Calin on 3/9/2011 2:25:59 AM , Rating: 2
My brother has a 3 or 4 years old Renault, and the most powerful 1.5l diesel engine had 87 HP. On the other side, you can drive it easily at 1800-2000 rpm and accelerate from there, and at 3500rpm the turbo really starts to kick.
So, I don't know about maximum power, but I find anything over 100HP in a 1.5l diesel difficult to obtain (and more expensive)


RE: Good.
By Johnmcl7 on 3/8/2011 5:02:05 PM , Rating: 2
There's a few smaller diesels available in the EU from various manufacturers for their small hatches but they don't tend to work particularly well as performance is poor and fuel economy isn't that much better over similar petrols.

It used to be that most diesel engines were a higher capacity and then the power output adjusted to suit the purpose, VW/Audi for a long time use a 1.9 diesel engine which varied from just 65bhp in its non-turbocharged form up to 150bhp for the sportier versions with various values in between. Now however they're replacing the lower powered 1.9's with a 1.6 TDI common rail engine with mixed results, it's meant to be a lot smoother than the outgoing 1.9 but fuel economy in practice isn't that great.


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