What is the end game? What I am trying to accomplish. Trying to figure out why two (same model same year BMW X5 4.4 sport etc) car drives so differently.

One seem to have more power that the other.

At dead stop one would when press on the moderate gas rev up to 2000 rpm and stay in gear (rpm goes from 2000 to 2200 and I am at 40-50mph) with out pressing more gas and I am more than happy with the acceleration (to the point of being scary).

The other would would rev up to 2000 rpm but would seem at that point if I hold the gas steady it would up shift while the other will stay at 2000 rpm (keep accelerating and becomes scary) at this point if I press more gas the rpm would go up to 2500-2800 before being at 40-50 and no scary feeling.

Again if I am not comparing what should be two identical cars. I would say they both drive normal.

Next steps. Any suggestions from you folks??? The only think I can think of is to change the tranny oil and spark plugs (although don't want to do that because it is not time yet only 28K miles on the clock).

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Silver Honda Accord, 2006
Silver G500, 2003
Silver SLK-320, 2002
Black ML-320, 2000
Bule Porsche 993 Targa , 1997
Silver Merkur XR4Ti, 1987