Gentlemen, I have a stock 05 4.8is and just did a minor tune up and other stuff before my long road trip with wife 2 kids and vehicle full of luggage. First I replaced all the fluids, from the engine oil with 10W-30, Diffs (X2) Redline, transfer case (BMW oil) Transmission with the redline D4. Then I replaced all Spark plugs (platinum), cleaned my dry Air filter (AFE), my MAF sensor and eliminated the hose that comes off the valve covers returning back into the intake part of the emissions, there are two, on the top of the intake manifold and the other that Y's off to the bottom portion. I Plugged those two up and vented to atmosphere the two that come off the valve covers. You do not need all that oil and gunk returning back into your intake, I know this has helped with the MPG. I also bought a bottle of the Techron fuel injector cleaner and Fuel system cleaner. Ohh, and changed out the Fuel pump on the X5 that was in my M3 (walbro 255LPH) and replaced new fuel filter. Walbro was overkill but I had it laying around. (I upgraded the M3s to an AEM due to needing more fuel for the 500WHP
)
I reset adaptations, reset transmission and went on my way.
Results are
Well, maybe I don't know all other X5 (4.8) enthusiasts MPG results. As I drove 1220 miles, from KS to NJ, I noticed that my MPG increased! I was getting 400 Miles per tank, I would fill up, and take off, (and I have a heavy right foot). On my way back today from NJ, I decided to take pictures and show my results. The first picture is my first 400 mile trip there was still like 1/16 tank left, as you can see approx 26 miles remaining. Then I filled up and took a pictures of the miles once I started again. At half tank I took another picture and it shows 234 miles at half mark, it looks on the picture like if it was less than 1/2 mark but it was the angle the photo was taken from. I Stopped at Hampton Inn for the night and will jet out in the am to post results!
Hope some of this helps for you guys out there looking to get better MPG and a better performing X5, because Let me tell you, all this work woke up the X5! response and throttle and fuel economy is totally noticeable.
03-27-2013, 01:38 AM
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