seri

Hello,

I'm an Audi A8 fan in the US and was amazed to see that the 3.0 TDI diesel verison in the UK gets 36-42 mpg!!

If this is true, I don't know why Audi doesn't make such a version available in the US. The only reason I gave up my A8 a couple of years ago is that I was averaging 15-17 mpg.

So, my questions are - is the posted 36-42 MPG accurate? And if so, does anyone know why its only being offered by Audi in the UK?

seri

If you have experience with the diesel A8, please me know what kind of gas mileage (mpg) you achieved. Thanks (in advance).

jetinder

Hi

So far, I'm getting on average about 34mpg (28 US mpg)with the 4.2 TDI. That's a mixture of town driving and highway.

On a strictly highway run at about 65mph, I've reached 44 mpg (36 US mpg). Give it a few thousand more miles (plus the MTM remap that I have), I'm sure we can add 10% or more to those numbers.

With my previous D3 with the same engine I once achieved 50mpg (41 US mpg).

I can't complain, I fairly easily get 600 miles per tank, which costs us about £105 each time.

The 3.0 TDI will be even more frugal no doubt.

Jet

Mikael

I recently test drove a new 4.2 TDI here in the UK and had the opportunity to have it for 24 hours. I took it on a drive to see my in-laws and was disappointed to get 31 mpg. The trip consists of a mixture f a-roads and motorways. I normally get 35 to 36 mpg in my current D3 4.2 TDI, doing the same trip. The performance of the new engine is great, but I could not find the claimed 20% improvement in fuel economy. I'm hoping the new 3.0 TDI bi-turbo producing 300 bhp, that was first seen in the e-tron concept in Paris will make its way into the new A8. It is supposed to arrive in the A7 soon, and also in the new A6 due to be released soon.

Glisse

I have not heard anything as to when, or how, Audi may introduce the new bi-turbo TDI engine. The A7 has only just commenced production, with the new lightweight version of the 3.0 TDI, the A8 has only had the high output version of the "old" 3.0 TDI this year, so I can't see them introducing the bi-turbo version until mid next year. Probably to coincide with the 4.0 TFSI V8 introduction?

I also think the bi-turbo TDI may be a replacement for the 4.2 TDI engine you and Jetinder have referenced. Whilst this is a magnificent engine, it is also extremely heavy. Improved efficiency through weight reduction seems to be a key medium term goal for Audi.

Audi always seem to keep their engine plans very close to the chest, which is a bit frustrating.

To the OP, the A8 with the 3.0 TDI is actually available everywhere except NA, so your question should be why Audi in North America isn't bringing it in. Historically, there was an issue with sulfur content levels in US diesel fuel. It is possibly more to do with low fuel prices in the US resulting in less sensitivity to fuel pricing, plus a pre-conception that diesel engines are somewhat agricultural. Also, I am not sure how passenger car friendly US gas stations are for diesel pumps. High flow diesel pumps intended to fill truck tanks don't translate well to passenger cars.

And yes, the 3.0 TDI can achieve the quoted fuel consumption figures. But it all depends on how you drive it. Audi, BMW and Mercedes are all quoting amazing fuel consumption efficiencies on their latest model releases. You would think there has been a watershed breakthrough in the design of the internal combustion engine. But the breakthrough is the transmission interface with electronic management programmes. The official consumption figures are achieved through engine tuning and fuel maps which enable the transmission to lug the engine around at minimal revolutions. Right on the brink of insufficient torque to be able to pull away. And lower than I would ever lug an engine with a manual transmission. So, in an Audi, set the Audi Drive Select to comfort, and never apply more than a slight, and gentle, squeeze on the throttle, only drive on totally flat roads, and you will achieve the quoted consumption figures. It is sort of okay with the torque converters in automatic transmissions, but it is horrible with S tronic transmissions - personally, I would prefer to walk than drive like this.

On a diesel, reduce the consumption figure by 10%, on a petrol by 25%, and you will be closer to real world results.

Mikael

I think you are probably quite right in saying the 3.0 bi-turbo TDI will not be introduced for a while. It would make sense to change the engine lineup all at once, if/when the 4.0 TFSI is launched.

I'm not sure if Audi will replace the 4.2 TDI though, as the engine is truly fantastic, and provides unmatched power and torque. However if the 3.0 bi-turbo TDI is introduced, I could see it being the best compromise for day to day driving, as it would make the front end of the car quite a bit lighter, and improve handling, whilst still offering the performance on par with the 4.2 TDI in the D3. I could see it taking quite a few sales away from the 4.2 TDI.