PistonHeads.com Forum

Mpg vs age/mileage



Original Poster:

3 posts

Thursday 7th September
quotequote all
Hello forummers,
Its been quite a while since I've had a new/nearly new vehicle: What people's thoughts on how we should expect the mpg returned by a modern diesel engine to vary over its life?
- Should it stay pretty constant?
- Highest when new, then gradually decline?
- Lower to start with, then improve over x-thousand miles 'running in'? (is that still a thing?!)
- something else entirely?

Interested to hear thoughts,


1,852 posts

134 months

Thursday 7th September
quotequote all
My L200 did about 32MPG new, down to 30MPG at 80k and was doing 29 ish at 130k when I got rid of it. So not much change over its life.
New A8 4.2 TDI did 34MPG at zero miles and now does 37 ish at 6k miles. So it seems to have loosened up a bit. My previous one a 2012 model did 38 ish at 46k miles but the 2012 was slightly less powerful than the later ones (350HP as opposed to 385HP).