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Old 01-25-2013, 01:14 PM
jlukja jlukja is offline
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Location: Long Beach, CA
Join Date: Jun 2012
Posts: 972
Mein Auto: '13 328i
Originally Posted by d geek View Post
Most modern vehicles cut fuel when your foot is off the go pedal. So even though you see the rpm's moving up and down you should understand that most of that is caused by the wheels turning the engine not vice-versa. Bottom line is that it does not negatively impact fuel economy.

Downshifting helps reduce brake wear and as pointed out above puts your trans in the correct gear for moving out again.
Agree. I would add that, in this situation, the braking comes from the opposing force of the air (without fuel) being compressed by the pistons. Without fuel you have compression without detonation.
MY2013 328i, N26 / 300 / 4CG / KCDF / 2DW / 205 / ZDH / 302 / 3DZ / 403 / 494
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