|
Few things on these that really effect MPG.
Winter diesel, usually goes to summer at the end of March.
Can be as much as 10% difference.
Thermostats. If it is not getting to 90ºc quickly and staying there rock solid change them.
Can stop DPF regens too, not good.
O2 sensors, pre and post cat.
These fail a lot and when they go the car uses a default map, can use as much as 25% more fuel.
You will need a scanner and look at the live data for these.
I have got a B47, I bought it after gobbing off about how little difference there is in overall running costs compared to a petrol.
I was gutted when I first got it that I was so right.
I was getting 33/34 round town, 44 at best on a run and averaging about 36mpg.
The switch to summer diesel saw that go up 3-4mpg.
Still not good.
I knew the thermostats were good so started delving deeper.
Found the O2 sensors were knackered. Swapped these and saw and instant increase.
I am now seeing 55mpg on a run and averaging 45mpg.
Even round town from cold is is high 30s no problem.
The B47 is meant to be worse for MPG than the N47, so you should be able to see this.
|