bad mpg just now-anyone else?

[martint]

just recently my 2.0 hdi has increased consumption from 49/50 to 44mpg.
ive read that cold weather has an effect on diesels but as much as 6mpg??
anyone else got this goin on just now? recently it failed mot on emmisions so mechanic put injector cleaner in & it passed. anything to do wi this i wonder

[lozz]

Not much you can do mate,
just check youve got the Correct Grade of oil,

Mine used to loose, 6mpg + through the winter,

[martint]

thats what im beginning to think as well-cold weather. sucks eh

[lozz]

Was the fuel treatment stuff put in recently?
if theres still some of this left in the tank, it will decrease you mpg slightly,
iknow Red-ex looses you a good 2-3 mpg, not sure on the other affect of aditives,

[martint]

yeah-and i never let it run til empty & put another £30 o diesel on top. i think that would only cause a minimal amount though,as he put some in filter housing as well.

[ZilogJones]

Mine's gone down by about 3-4 MPG in the last couple of months, but traffic has got worse (kids back at school, etc.) so my average speed has gone down a lot too (you have a trip computer?). I've noticed it takes a bit longer for the engine to warm up, and having things like the rear window demister, heat, lights, etc. on more regularly will have an impact on fuel consumption too.

Still hasn't got cold enough for me to see if my glow plugs work...

[Welly]

It's the cold-start enrichment program of the ECU otherwise the engine would never warm up (think old-fashioned 'choke').

Mine used to drop 4 or 5 mpg in the cold weather, I found that letting the car idle on its own for 5 mins or so would help it warm up, in fact I used to do it everyday although I live in a very quiet spot no-one would even notice a running car.

It is good practice to do 'seasonal' oil changes on a diesel where you'd change the oil in approx October and then again in March to get rid of the crap winter oil after it has done all those cold starts.

Change the air filter every 12 months and keep the tyre pressures to 33PSi all round.

[omega]

we had a simalar thread last year about this
my car is diffrent
my mpg gets better in the winter!!
i think its because the cold air makes the engine work better

[rwb]

You've got an XUD haven't you omega?

Time to get my graph out again

[omega]

[quote="rwb"]You've got an XUD haven't you omega?

no a 2.1

[steve_earwig]

Aka XUD11BTE

[omega]

Aka XUD11BTE

ah didnt know
thought the xu was only the 1.9