2008 X5 4.8 Software upgrade for Transmission

[bbjr]

I had the software upgrade done on my 2008 X5 4.8 to improve the shifting characteristics of the transmission. After picking the car up at the dealership and driving it now for 2 weeks I notice no difference what so ever the vehicle still doesn't up shift soon enough (at times till 4000 rpm).
Has anyone else had this upgrade done? Also, I'm only averaging (combination of city/highway)at best 12.9 mpg...anyone getting better mpg? My 750li averages 20.1mpg.

Thanks

[awesomejun]

I did have tranny reprogrammed in October and yeah.. as you mentioned, I notice not much difference even after the reprogramming.. but the jerky stopping's sort of got better.
I'm getting around 12.8mpg. MPG worsens as winter comes..
I guess it's because of snowy cold weather in western NY.
Less traction/extra engine warmup in the morning --> more gas --> lower MPG..

[Barcius]

Originally Posted by awesomejun

I did have tranny reprogrammed in October and yeah.. as you mentioned, I notice not much difference even after the reprogramming.. but the jerky stopping's sort of got better.
I'm getting around 12.8mpg. MPG worsens as winter comes..
I guess it's because of snowy cold weather in western NY.
Less traction/extra engine warmup in the morning --> more gas --> lower MPG..

No reprogrammed so far here, but fuel economy is much better @ around 16mpg. Also shifting happens at a much lower rpm around 2,800.

[deutsch100]

Transmission is awful, and my SA (honestly, actually) told me that the software update really won't make much of a difference. MPG is truly shocking. Yes, I know it is a V8, massivley heavy SUV....but most of my conservative city driving yields about 10-11 mpg.

[rh71]

I don't know how any of you would get above 15mpg, considering I only get 16mpg mix highway in a 3.0. I'm avging only 15mpg right now actually.

[stockguru]

I have a 3.0 as well and am averaging 15 mpg mixed (13 city and 18 hwy) Not sure what ridiculous conditions were used in the testing to get the advertised rates. My guess is it was done going downhill with a 50mph tailwind on ice where the car slid for 2 miles without gas.

[bbjr]

Originally Posted by rh71

I don't know how any of you would get above 15mpg, considering I only get 16mpg mix highway in a 3.0. I'm avging only 15mpg right now actually.

I used to have a 2006 X5 4.4 and I averaged in the high 16 mpg range?

[wdc330i]

Originally Posted by stockguru

I have a 3.0 as well and am averaging 15 mpg mixed (13 city and 18 hwy) Not sure what ridiculous conditions were used in the testing to get the advertised rates. My guess is it was done going downhill with a 50mph tailwind on ice where the car slid for 2 miles without gas.

My city driving (more stop than go) yields between 11 and 13. A recent hwy trip however reached a steady 23.5. 3.0 engine.

[X5rolls]

16.8 mpg - mixed driving - 06 4.8is

[Barcius]

Originally Posted by rh71

I don't know how any of you would get above 15mpg, considering I only get 16mpg mix highway in a 3.0. I'm avging only 15mpg right now actually.

There is very little difference in mpg between the 3.0 and 4.8 in real world driving conditions. Even EPA numbers shows there isn't significant difference between the 2 engines in fuel consumption: 14/19 for the 4.8 and 15/21 for the 3.0si. In real world you are probably accelerating your engine more to compensate for the lack of power what causes an increase in fuel consumption. That is the reason I went for the 4.8: it is a blast to drive, has an awesome sound and the fuel economy is similar to the 3.0si. The only issue is the price of admission.