2009 E70 - Diesel Fuel Consumption Issue

[sanjivsai]

Hi Everyone,

      BMW X5 E70 XDrive 30dSE (2009)  Mileage:15,000

I hope someone can help me.
I recently noticed that my fuel consumption had changed (just got car back from a garage). My car is using more fuel.

                           
Before      75 litres fuel    280 - 290 miles
After        75 litres fuel    250 - 260 miles

My driving style has remained the same, load in car is similar, routes prety much the same, and I am using the same fuel as I have always done.
The garage have said that everything is OK and it is my driving habit.

Can some help me out as to what the probable cause/s could be?

Many Thanks in advance for all your help.

Sanjiv

[petert]

I notice an increase in fuel consumption in the winter as well in my 2010 35d. Dealer says it's normal. Change to winter diesel perhaps? I'm not truly convinced and it is a bit of a turn off for me buying the car at the end of the lease but I've yet to make up my mind. Got a couple of months...
Peter T

[sanjivsai]

This has been onging since June. Can't be that surely.

[pvr]

Are you the only driver?

I know that I get about 20% more out of a tank than Mrs PVR as she drives the X5 as if it is a Mini ...

[sanjivsai]

Yes. Sole driver. Fuel Consumption only increased after car came back from garage.

[pvr]

I assume at that mileage, that you only had an oil service? Not sure if they can really screw anything up when just flushing that part of the system.

Perhaps try a different petrol station to see if there is anything in the fuel you are using?

[sanjivsai]

Thanks for your response. I got the car back after a power steering hose split - fixed under warranty and noticed the difference the next day. Got these figures after carrying out a fuel consumption test. Have tried a different petrol station maybe I should try a different bbrand of diesel.

[X5Sport]

Any change on how the PAS is performing? Possibly drag from the pump maybe affecting the engine. Are the PAS fluid levels OK? Did the pump run dry and they've just replaced the hose leaving a possible issue hiding in the actual pump itself?

[X5Sport]

[quote=""pvr""]I get about 20% more out of a tank than Mrs PVR as she drives the X5 as if it is a Mini ...[/quote]

Oh great - that really helps!! Bang goes all the justification for HRH getting the Mini then

Now I'll have to find how to disable the 'Sport' button on Wilma

[sanjivsai]

sure, if it ran dry, was definately low. The PAS pipe from pump to rack was leaking.. Have not noticed any change in handling.

[pvr]

I trust you have checked the wheels / brakes to ensure there is not a sticking caliper? If that was the case, you would see a red hot brake disk and a lot of heat coming from it ...

[sanjivsai]

No. How do I check this ?

[pvr]

After a drive, feel the wheels. Normally, they are warm. If it is very, very hot that implies that the calliper is sticking.

[shadrack]

i had this in the last 3 weeks my average has dropped from 31.9 to 28.9/29.9 so 2-3mpg so i put it down to the change in weather as my old petrol one used to drop from19/20to 16/17mpg in winter

[X5Sport]

Very carefully so you don't burn yourself! Place your hand a few cm away from each of the four wheels in turn and see if the brake disc seems warmer, or again carefully put your hand on the centre of each alloy wheel and see if one is warmer than any other. You can do the same with the tyres to see if one tread is warmer than any other - which may also indicate a tyre pressure issue.

Are there any errors on the iDrive check control system? Low pressure warnings etc? Is the car steering pulling in any one direction more than another?

If you can find a flat, straight, level piece of road to drive down with no other traffic so you can drive on the 'crown' of the road, does the car head off the crown to left or right? May need a few checks driving in both directions of travel to confirm any tendency for the car to come off the crown consistently in the same direction. This could be caused by wheel drag 'steering' the car by slowing one corner. A front wheel dragging will tend to pull the steering wheel in that direction and a rear wheel will tend to make the car tend to pivot on that rear corner to left or right.