Peugeot 508 SW MPG Issue

[Pug508sw]

I have a 508 SW 2.0 Diesel 61 reg, I have just gone over 74k miles and have suddenly lost 10mpg off my average (54.8-44.7). I am not driving any differently and using the same fuel company, nothing sounds out of the ordinary from the engine bay throttle response etc is the same as well. Is there something I need to be looking out for?

[Peter.N.]

Is it actually just indicating less mpg or have you checked it by brimming the tank? The reason I ask is that I have a C5 and 406 both with the 8 valve 2.0. hdi, they both indicate about the same mpg but when checked the C5 is actually using something like 20% more fuel and yet it drives and behaves perfectly - apart from its propensity to suddenly stop when overtaking

The 2.2 engine also is disproportionately poor on fuel for no logical reason although a few people get good mpg from them so its a very difficult problem to solve. The only thing I have't tried is the injectors, it could be that one or more is leaky. You can do a leak off test yourself or put a Lexia on it and see what that tells you.

I would be very interested to know the outcome.

Peter

[Pug508sw]

I Had a thought that maybe one of the injectors are leaking and will look into this possibly this weekend. Even though it is is just indicating that the car is doing less MPG i have noticed it in fuel consumption also. If I find a solution I will keep you updated.

[Lighty]

May be that your DPF filter is getting blocked, it certainly will not be perfect with 70 k miles on .

[MikeT]

Whenever my ave mpg drops by around 6-7mph, I know I have to reflate the NS rear tyre to recoup it.

[Peter.N.]

I have just bought another 406 estate, very nice car and very well maintained, went out in it yesterday on a journey that normally gave 50-60 mpg on the old one and got 45 mpg.

Peter