There was talk a couple of weeks back regarding compression braking with an auto... a few folks replied that it's bad for the auto and some replied it's bad for the 5 speed as well... funny enough though, will looking through my S2000 owners manual, it mentioned that you can get more braking by down shifting. If fact, this is what it says:

"When slowing down, you can get extra braking from the engine by shifting to a lower gear. This extra braking can help you maintain a safe soeed and prevent your brakes from overheating while going down a steep hill. Before downshifting, make sure engine speed will not go into the tachometer's red zone in the lower gear."

Now I remember back in drivers ed... they told us to use a lower gear when decending a hill... so it can't be that bad for the car, plus there's no load when you do this.

-Shing

 

Well the guy that taught me to drive was a mechanic and a professional driver for many years, so I trust his opinon. He told me to downshift while slowing down, so that's what I do. Helps that he's my dad.

I downshift my current Honda as well (it's an auto), and have had no ill affects.

 

Agreed... as long as you rev match, I believe everything is fine. But if you don't, it'll be jerky and will eat clutch.

-Shing

 

bad for the manual trans? nah.. like the other dude stated, if the revs are matched, there's not a whole lot of extra strain placed on the drivetrain. I downshift into lower cars when coming off the highway and onto exit ramps. When coming to a stop at intersections, I shift into neutral and use my brakes.

 

How do you rev match in an automatic?

 

Engine braking may not be bad for the tranny but it's not that great for the valvestems guide seals... You'll be looking at headwork sooner than normal...

As for me.. I'd rather buy new brakepads early then get a head job early...

 

Yeah, I'd rather have a little extra wear and tear on my brake pads than a lot of extra high-RPM wear and tear on the engine. There was also discussion on here a while back about the engine not getting enough oil under that condition because the engine isn't under load (no throttle input). Don't know about that for sure, though.

 

You don't rev-match in an automatic, no clutch to bring RPMs up.

 

Shing,
Making a habit of downshifting for every corner or stop will in the long run add wear and tear to the drivetrain, but occasionally heal and toeing and smoothly matching rev's to downshift in the spirit of fun won't do great harm and certainly is in the nature of your S2000 and CRX.
Especially as they are well maintained by you.

I certainly don't let moss grow on my butt when I drive and my SAAB 99 lasted 17yrs and 170K miles of my downshifting abuse and was still going strong when I traded her in on the Maxima. None of my straight stick cars or trucks ever showed signs of premature damage from proper downshifting.

Automatic transmissions, before the days of emission controls and FI, use to actually have some compression drag as you slowed down, something I miss with today's automatic's.

-Mark

 

I guess it's one of those things where if you do it, now your tranny/engine will last 190,000 miles instead of 200,000.

Hrmm... I drove the S2K all over yesterday... my face is a little toasted.

-Shing

 

If you're not down shifting, as your speed drops, I don't know why you bought a manual transmission car in the first place. (Oh right, everyone here is into acceleration.) There is no extra strain on the engine. Oil flow is determined by RPMs, not throttle opening. Cars with auto trannies still provide engine braking, if you're in a lower gear. Down shifting an auto, while slowing down, can be made a little smoother by blipping the throttle as the tranny shifts. Can't sync things like a manual, and it is hard on the tranny, but it works.