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Re: Cruising RPM
What I learned from my BMW with SMG on "automatic" is the computer often selects an RPM value much lower than I would have chosen on my own. So I guess my (our) fears of lugging the engine have caused us to assume a much higher than necessary RPM is needed for level-road cruising with a manual.
Getting to 100k without a rebuild notwithstanding, I'd say it's personal preference what RPM you choose when cruising because, unless the thing is OBVIOUSLY chugging and lugging, you can't hurt our engines, you can only hurt gas mileage.
Getting to 100k without a rebuild notwithstanding, I'd say it's personal preference what RPM you choose when cruising because, unless the thing is OBVIOUSLY chugging and lugging, you can't hurt our engines, you can only hurt gas mileage.
Nov 6, 2005 1:57:40 PM
- FixedWing
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Re: Cruising RPM
I knew someone was going to say that. If one can double-clutch then this isn't a problem as the downshift can be almost instant. Sometimes you want even more than 3000 RPM so the forumla of keeping it at that RPM isn't always ideal. So I'll often trundle along in 6th in trafic and then double-cluch into 2nd for a quick pass.
Stephen
Stephen
Nov 7, 2005 8:15:55 PM
- 69bossnine
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Nov 7, 2005 8:32:12 PM
- throt
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Nov 8, 2005 3:06:09 AM
- FixedWing
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Re: Cruising RPM
Quote:
69bossnine said:
Double clutching is for non-synchronized gearboxes. The 911 (as almost all modern cars are) is fully synchronized. Why are you bothering to clutch twice??
Because I can shift faster from 6th to 2nd for a pass if I use the engine to spin up the transmission than I can if I use the syncros to spin up the transmission. And obviously doing so places less wear on those syncros.
What's more, I can release the clutch faster when re-engaging the engine and transmission because I've already spun up the engine from the double-clutching I just did to get the transmission spun up. So I know that the engine is rev-matched to the transmission speed.
The end result is a much faster and smoother downshift. Smoothness is important because it is less likely to unsettle the car.
Stephen
Nov 8, 2005 5:30:02 PM
- MMD
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