I've had my A4 for over 5 years now and I'm looking to upgrade soon. I have been reading up on the A6 with the 4.2L. I think it might be the better choice over the 2.7T because theres no turbos to wear out. In the factory specs the listed fuel mileage is almost the same as a 2.8L A4. But reading some reviews people are saying they aren't easy on fuel. I searched but didn't find much. What kind of mileage are you guys getting? 4.2L and 2.7T Quattro A6s.

Thanks...

 

It all depends on how you drive. with the 4.2 you are pushing a v8 every time you step on the gas, and that means its going to eat fuel. On the highway with a lightfoot you can probably get decent mileage, maybe even close to the 2.7 or 2.8, but in stop and go traffic or stoplight to stoplight you probably wont even see 20 mpg very often.

Driving through the mountains on cruise control at 65 mph I can get 35-40 mpg, drops down to about 23-25 when I hit a pass though, I average about 30 though once you account for coasting down the backside.

 

I'm not talking about what the computer is telling you by reading sensors. I was really referring to real world fuel mileage measured by setting odometer to zero and filling the tank. When the tank is empty refill it and divide the miles by the gallons it took to refill it.
Considering your tires are still stock size so the speedometer is reading correctly would be the most accurate way.

Thanks for replying

 

One could always recalibrate the ECU-fuel readings to correspond to the real life consumption.

 

You'll get low 20s on the highway and high teens around town with either engine. There are pluses and minuses to both engines. Fuel economy is not one of the pluses.

Good luck,

Bob

 

I've driven my A6 from 37k to 176k and kept track of actual mileage. It averages around 17-18 mpg in town and ~23 mpg on the highway at 70-75 mph. Go faster and it drops. On a recent trip through Indiana where the speed limit was 55-60 and I drove around 62, I approached 25 mpg. I generally accelerate rather gently, rarely going over 3000 rpm, and drive mostly highway.
I'm still on original turbos.

I understand from other posts that the 4.2 may be a little more efficient on the highway and is worse around town.

 

I can live with either of those estimates. My old 2.8L 12 valve averages about 24 to 25 tank to tank but in cold weather it drops a couple of miles. I was shooting for the 4.2L because I have heard the turbos on the 2.7T don't last much past 80K and they are fairly expensive to replace. That and timing belts. Also if I go 4.2L with the newer engine 2005 and up they have timing chains. I guess while I'm at it I might as well check out the A8s also.

Thanks Guys...

 

23 hwy and 17 city on my 00 2.8. Have had it for 4 years now and 60k