Manny

Anyone else with an A8 like to share their GAS mileage. Amazingly, my new A8 seems to better the mileage I used to get with the 97 A4 2.8Q. After 2 weeks (~1700 miles) the A8 is getting an average of 22 MPG (combined City and Highway). It seems to get about 18 city and about 24 highway. This is with spirited 75+ MPH driving. I figure it will do better once the novelty wears off.

The 97 A4 was getting about 21 MPG average. I also have a 96 2.8Q that seems to get 22-23 MPG average (combined).

Given the 24 Gallon tank in the A8, I love the almost 400 mile range. I used to fill-up twice per week with the A4s with the daily commute - the A8 needs only 1 trip to the gas station.

Ali B

I think the EPA numbers are 17 city /25 hwy for the A8 4.2 quattro. This is remarkable when you compare them to the numbers for the much smaller A4 2.8 quattro/Tiptronic (17/27). The light weight of the A8 pays off nicely in performance and fuel economy.

Manny

I wonder if it is not that the A8 is so light, but that the A4 and A6 are really that heavy. At 3400-3600 pounds - the A4 is not exactly lightweight. When you consider that bigger sedans like Camry's and Maxima's weight less than the smaller A4 (by about 200-300 pounds), I think that tells a lot about the gas mileage.

On the other hand, when you consider that the A8 is only 400 lbs heavier than the A4 - that is amazing.

Ali B

The old S-class was over 4500 lbs, and the current 740i weighs over 4200 lbs. Compared to those cars, the A8 is light, especially when you consider the weight penalty imposed by quattro. The 2000 A8 is yet another 100 lbs or so lighter than before with additional use of aluminum in the suspension components.

Bill Mills

I have a '97 A8 4.2 (US model) and that seems to be the kind of milage I am getting (21-22 mpg combined). I live in a small town in a rural area so most of my miles are driven on highways. I did a quick test with the on board computer one day which reported 25.5 mpg on the highway portion of my drive home from work but I just bought the car two weeks ago and have not taken it on any long highway drives so I have no way to confirm the number the computer gave me yet, I am only on my second tank of gas. I reset the average mpg on the computer just before the last fill up so I can confirm numbers when this tank is drained.

GregWork

Typically get 15 City/ 25 Hwy
But have gotten as high as 28 Hwy

2001 S8

I have a 2001 S8 that is new to me (almost 3 months) and in combined driving I am getting 17 mpg on premium gas with no ethanol added.

I just had an oil change and installed a K&N replacement air filter so I will see what gains, if any, come from the recent service.


2001 S8
Black on Black

TXcajunman

i average 18-20 in town on highway don't remember mpg but did get from Joplin Missouri to Amarillo TX on a tank about 500 miles going 70-75 the whole time and still had gas in town for a cpl days

Adjuster

The S8 does not get as good gas mileage as my A8L did, or my A8 before that.

The 2004 had a 6 speed transmission, while the 98 A8 and my 2001 S8 have the 5 speeds, but the final drive on the S8 is lower, so the engine turns faster all the time.

It's really too bad that Audi did not have ZF equip the S8's with a higher final drive, but since it's the same transmission, the S8's will always get lower gas mileage.

But they are faster off the line, and more fun to drive, so it's all a trade off, and I did not buy this car for fuel economy.

Come to think of it, I never bought any of my Audi's for fuel economy. (It's just a happy benefit that you can drive a fun sedan, and still not pay too much for fuel while having your fun.)

Even with the S8.

nyrobbie77

on my 97 A8 running 87 octane i'm getting about 22-23mpg, about 450-480 miles per tank.

I drive mostly highway, about 75 miles round trip per day. generally i'm easy on the throttle with a few romps per tank.

I've been using 87 octane for about 2 months as a test, logging fuel consumption in my iphone Roadtrip app. I'm trying to compare fuel consumption and price vs using premium. regardless of octane, unleaded fuels have the same Btu's, so the only benefit to running higher octane is to be able to run more ignition timing which then provides a bit more power. for normal driving, I don't notice any difference, but it is noticeable when I flog the loud pedal.

I wish the trip computer was more accurate tho. it seems to calculate the remaining distance based on instantaneous mpg, rather than overall. I haven't reset my overall average in some time, which is fairly accurate. the trip computer is always over optimistic, saying that I will get 600-700 miles on a tank. I tend to get 450-480 miles per tank (~20-21 gallons). once I get below a half tank, the range calculation is a bit more accurate.