Hello, I have a question, I have a x5 2002 3.0i, a few days ago drove another x5 2005 3.0i runs much lighter, accelerates faster than mine, mine has 20" rims and my mother has 17" rims. Running 55 miles and accelerate, X5 my mother to accelerate faster than my x5. Any ideas?? The X5 don't have any modification, no check engine light.

I am thinking maybe vanos are not working correctly, maybe the fan clutch, i don't know. spark plug are laser platinum 3199