[kmarei]

X3 35i Vs 335i
both have the same engine (N55)
335 does 0-60 in 5.6s for 6sp auto
X3 does it in 5.5s 8sp auto

X3 weighs over 600lb more
????????

328i Vs X3 28i
weight diff is about 700lb
328i does 0-60 in 6.9s
X3 28i does it in 6.7s

any ideas?

[fedinand]

..traction and the 8 speed are the only differences. Just as BMW states the 335xi is quicker than the 335i to 60 in spite of its 200 pound+ weight disadvantage. It's a similar concept here…except there is the additional advantage of the 8 speed. I found the quoted numbers to be hard to believe also, but after a test drive it seems plausible (still would like to see independent test results). I think the 335 would walk away after 60 mph due to weight and aerodynamics, but traction counts for a lot 0-60.

[raleedy]

AWD surely makes a difference for this test. Another thing to look at is the final drive ratio.

[fedinand]

looks like BMW's estimate was spot on:
C/D TEST RESULTS:
Zero to 60 mph: 5.5 sec
Zero to 100 mph: 15.2 sec
Zero to 120 mph: 23.2 sec
Street start, 5–60 mph: 6.3 sec
Standing ¼-mile: 14.2 sec @ 97 mph
Braking, 70–0 mph: 165 ft
FUEL ECONOMY:
EPA city/highway driving: 19/26 mpg
C/D observed: 18 mpg