My girfriend Julies has just bought a 1997 A6 2.5 TDI (140bhp). According to some reviews it should get an average mileage of 46 mpg. So far we're getting around 40 mpg on motorway cruises (75-85 mph). Is that normal, or is there anything I need to check?

I have noticed a small amount of black smoke coming from the exhaust - not from inside the car but when I was following my girlfriend as she was drove it. Could that have something to do with it. I don't know too much about Diesels.

Cheers.

 

The best I have had was 46mpg when driving pretty slowly. I get 40 in the winter and 43 in the summer, so you are probably Ok wity 40 given that mine is the 155bhp later version.

 

Is it the5 Cylender model ?

- I had the 155 bhp (6 speed 5 cyl) and got 47 mpg regularly on longer doistances

I now have a 6 cyl 2.5 tdi 130 bhp and get 35!

cheers

Richard

 

130 bhp 2.5 V6 --typo I presume, you mean 180 which is pretty thirsty like the new 2.7TDI that is actually thirstier than the 3.0TDI if substantially cheaper - hoping to order one today...final negotiations on ease and extras.

Andrew

 

Black smoke can be caused if the engine is running rich (too much fuel is injected and can't burn completely), injector malfunction, incorrect timing, overfueling and internal injection pump problems.
Another common cause of black smoke is an air intake restriction. Check your air filter, intake hose(s) and exhaust. If that checks out you could get a K&N airfilter which will let the engine breathe a little better.

 

no the power levels not a typo even the lower power version of the 6cyl engine is thirstier than the old high power 5 cyl. - But they are the older models - 1999 & 1996..

By the Way - Diesels to somteimes emit a little smoke - partularly when changing gears - if it is not lots of thick black smoke I would not worry too much!

Hope the purchase goes well!!

cheers

Richard