Any tips???
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From: Austin
Looks like this old "does decelerating with the engine hurt the car" debate has returned ... 
From my understanding of how the transmission/clutch/engine works, the only hurt you can do to the system when engine braking is the clutch --- and only if you don't rev match during the downshift.
Think about it, you have an engine/transmission designed to survive 240hp for 100,000 miles or more, I don't think it'll be harmed all that much from compression braking. Last time I let off the gas completely, the car didn't brake anywhere near as hard as full throttle. By my guess, you get probably about 10-30% of max regular horsepower in compression braking for a given engine RPM. Due to the way that throttles work (in that they never quite close, always letting enough air through to allow idle power), you get a higher % of braking power at higher RPMs.
My point is, when the drivetrain is engaged, engine braking isn't nearly as hard on the engine/drivetrain as full throttle, or even half throttle.
What about the engine you say? Well think about it: Compression braking occurs all the time. A simple examination of the 4-stroke cycle demonstrates this. It's just usually masked by the power stroke so you don't notice the negative power. An engine designed to take 240hp of power output for 100,000 miles can easily take a quarter of that in compression braking.
So this leaves the clutch. Clutches don't wear when they are fully engaged in exactly the same way that parking brakes don't wear when the car is parked. It is *slipping* the clutch that causes friction and heating, which causes degradation over time. But, if you rev-match on the downshift, this is no worse for the clutch than up-shifting. Ergo, unless you feel that regular shifting is harmful to the engine/drivetrain, a properly executed rev-matched downshift isn't going to be a horrible thing to do To suggest otherwise is to say that people who get from 4th to 6th via 5th are doing more harm to their than going directly to 6th from 4th. I guess we should all attempt to shift as little as possible due to clutch wear and tear 
I'm curious where this myth about compression braking comes from. Looking at the whole effect and thinking about it, I just can't figure out where the car gets so much extra wear and tear from compression braking. A minute of 60mph driving on the freeway should cause more wear and tear than 15 seconds of compression braking, by my estimate.
Ah well, maybe I'm wrong and Honda has some big class-action lawsuits headed their way for suggesting compression braking in their manuals
From my understanding of how the transmission/clutch/engine works, the only hurt you can do to the system when engine braking is the clutch --- and only if you don't rev match during the downshift.
Think about it, you have an engine/transmission designed to survive 240hp for 100,000 miles or more, I don't think it'll be harmed all that much from compression braking. Last time I let off the gas completely, the car didn't brake anywhere near as hard as full throttle. By my guess, you get probably about 10-30% of max regular horsepower in compression braking for a given engine RPM. Due to the way that throttles work (in that they never quite close, always letting enough air through to allow idle power), you get a higher % of braking power at higher RPMs.
My point is, when the drivetrain is engaged, engine braking isn't nearly as hard on the engine/drivetrain as full throttle, or even half throttle.
What about the engine you say? Well think about it: Compression braking occurs all the time. A simple examination of the 4-stroke cycle demonstrates this. It's just usually masked by the power stroke so you don't notice the negative power. An engine designed to take 240hp of power output for 100,000 miles can easily take a quarter of that in compression braking.
So this leaves the clutch. Clutches don't wear when they are fully engaged in exactly the same way that parking brakes don't wear when the car is parked. It is *slipping* the clutch that causes friction and heating, which causes degradation over time. But, if you rev-match on the downshift, this is no worse for the clutch than up-shifting. Ergo, unless you feel that regular shifting is harmful to the engine/drivetrain, a properly executed rev-matched downshift isn't going to be a horrible thing to do
To suggest otherwise is to say that people who get from 4th to 6th via 5th are doing more harm to their than going directly to 6th from 4th. I guess we should all attempt to shift as little as possible due to clutch wear and tear I'm curious where this myth about compression braking comes from. Looking at the whole effect and thinking about it, I just can't figure out where the car gets so much extra wear and tear from compression braking. A minute of 60mph driving on the freeway should cause more wear and tear than 15 seconds of compression braking, by my estimate.
Ah well, maybe I'm wrong and Honda has some big class-action lawsuits headed their way for suggesting compression braking in their manuals
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