backtop


Print 51 comment(s) - last by Keeir.. on Mar 10 at 7:53 PM


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.



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

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.


"If they're going to pirate somebody, we want it to be us rather than somebody else." -- Microsoft Business Group President Jeff Raikes

Related Articles













botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki