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Old 02-10-2007, 04:14 PM
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Quote:
Originally Posted by JCL
...Holding it in a lower gear doesn't hurt the transmission, but the shift itself does cause wear on the clutch packs. BMW engineers the transmission controls to reduce the shock when the transmission upshifts (by backing off the throttle via the ECM), but that effect isn't there when you downshift manually. Downshifting at every stop sign and exit ramp will likely shorten transmission life...
Very helpful post, JCL. From what you're saying, it sounds like it would be better to keep the X5 in S mode rather than downshifting manually, since presumably BMW's engineers have made the shock to the transmission less traumatic to the engine when it downshifts itself (which, in S mode, is at higher RPMs, therefore providing at least SOME compression braking, whereas in standard auto mode, there is virtually NO compression braking), right?
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