Very poor mpg at 21.5 mpg
 

I'm getting very poor mpg on my D5, whether I'm doing short journeys or long journeys. I'm averaging about 21.5 mpg or at most 21.8 mpg.

What's the reason behind this?
What's the best additive to buy?
How much are you averaging?

that is a bad mpg i get 43 to 40 out my d5

I think it needs a full tank of Shell fuel, and millers additive. That should do the trick.

if only life was that simple!

I agree with you there. From what i think the previous owner has not taken the car on the motorway, so it could be that the engine has not been opened up, as it's only done 43K miles. Might take the car on a long trip, and see if i could get the mpg up to 40mpg.


Which fuel do you use, and what additive do you use?

When was the last MOT? What were the emissions like?

Try plugging in an OBDII reader to see if you have a fault code listed

Last MOT was done April 2011, i haven't checked the emission info. Will have a look at it now.

I don't have the copy of the emissions test. Same thing happened today, reseted the mpg to 0.00 took it for a normal test drive, and the mpg went up by 25.8 mpg. That is still very poor, can't get my head around on what's causing the problem.

Does the fuel filter need changing?

I hope not?

It would mean your 8 months out of date for an MOT? Although I'm sure you meant Apr 2012.

:star-wars-smiley-01

Sorry meant to say last MOT was done April 2012, next MOT is due May 2013.