Mpg too good to be true

**audia6driver** · 25-01-2017,08:36 PM

True. But do you remember the ad for your Audi 80....
at 70mph you can hear the pin drop..wow

**M1tchy** · 27-01-2017,07:39 AM

I went from Pembrokeshire to catterick in the summer in my biTDI A7. Air con on the whole way and according to the computer got over 50mpg on average. Obviously I used the motorways which are all 50mph for no reason and covered by billions of cameras but was really happy with those figures. Got there and back on less than a tank.

Sent from my iPhone using Tapatalk

**Joe2.0E** · 21-02-2017,10:09 PM

My D3 A8 3.0TDI regularly averaged 40mpg over the years I had it. It's replacement (D4 A8 3.0TDI) does 45mpg all day long and can get close to 50mpg on a long motorway run.

**audia6driver** · 23-02-2017,10:12 PM

That's pretty impressive for a big car, I think the aluminium body helps

**Joe2.0E** · 26-02-2017,09:31 PM

I'm sure it helps but I think the benefit is mostly from high gearing. At 70mph, a 3.0TDI A8 is in top gear and the engine is barely at 1600 RPM. By comparison, a Q7 with the same engine will only do 30-35mpg at best.

**audia6driver** · 27-02-2017,10:52 PM

I agree, but for me weight has a lot to do with it...

I drove a q7 with the same size engine, 4.2tdi and the owner told me he got 21mpg out of on a long run on the motorway, my a8 does better.

The same for the x5 and the 730d, same engine but 730d much more economical.

**Joe2.0E** · 28-02-2017,09:13 PM

Certainly weight is a factor as is the height and overall shape of a Q7. I think the early Q7 3.0TDI's have really poor gear ratios though. At 70mph in top gear it is at 2400RPM. I presume it is to suit towing, off roading etc. but for roadwork it really feels like it needs some higher gears. The 2011 facelift brought an 8 speed Auto to the Q7 which is a little better on juice.

**audia6driver** · 28-02-2017,11:32 PM

I drove the q7 and it felt good.

I think my A8 is doing about 1700 at 70, but then again it is 0600 at idle, so hardly a sweat for tHe engine.

Big 4x4 are not setup for economy, i was thinking of buying a Cayenne 4.5, but was heavily putoff by the 10mpg, that's getting to supercar mpg and Cayenne is not that.