My economy is getting worse! ?

[JED]

Don't understand what's happened over the past couple of weeks. On my usual 30 mile commute to work in my 170TDi I could always get 48mpg on the DIS, however, with exactly the same driving over the past two weeks I simply cannot get above about 42 to 43? What's going on?!! The only thing I can think of is that I usally fill up with Shell Dieselt Extra but the other week I topped it back up to full with about 4 gallons of Sainsburys - could this have contaminated the tank some how????

 

[consilio]

Its the colder weather

 

[JED]

Really? That's a big reduction !

 

[markwiggy]

Really? That's a big reduction !

Yep, car takes alot longer to warm up, therefore more fuel !!! also cold air = more power so maybe more fuel ???

Mark

 

[Macduff]

Yep, car takes alot longer to warm up, therefore more fuel !!! also cold air = more power so maybe more fuel ???

Mark

Correct. The cooler the air the denser it gets and this more fuel is required to keep the mixture correct. The upside of this is that your car will be more powerful so potentially you should need lighter throttle openings to do the same speed. A bit like a free remap!

I think the main issue with mpg dropping is the fact that the car takes longer to warm up.

 

[motorbikez]

Check that you are not on function 2 of DIS as mine shows 43 mpg which is what it has averaged over last 8500 miles.

 

[Boydie]

plus sainsburys deisel is crap - its low sulphur and its not liked by the 2.0tdi's I find!

 

[emzino]

But shouldn't you be getting more fuel when you fill up because of the colder denser air so it pretty much equals each other out... just about

 

[JED]

Well I definitely won't be using anything other than BP or Shell from now on!

Thanks for the input.

JED

 

[Boydie]

I use Texaco quite a lot and have no problems with it! (but it did used to be BP lol)