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Do you sequentially downshift or put it in neutral when approaching a red light?

What are you doing in 4th going 50mph. I usually cruise around town between 2nd and 3rd if the speed limit is 40mph. The only time I ever hit 4th or 5th is when I'm on the highway.

In a 6 speed?

With my 6-speed, I would say I always use 4th gear around 40 mph (I don't recall what speed I am at precisely, but it is around there).

2nd would be extremely fun, but a waste of gas to drive like that all the time.
 
Well it's the opposite of what everyone is saying IMO. When you press in the clutch and start playing with your gears without having shifted to neutral and letting the clutch out (double clutching) you have not slowed your shaft speed. You are asking the synchros, the most vulnerable part of the trans to do work.

So while you think you are saving your transmission by not rowing down through your gears one by one, you are actually wearing it out more. What is vulnerable here is the clutch, and the clutch wears very very little when you rev match. If you don't rev match, that's a different story. If you are going to coast and go through your gears, you should go to neutral, let off the clutch, reduce shaft speed, then hold the clutch back in and row through. The key is always during that double clutch, where you've let the clutch out in neutral, you've reduced shaft speed.

As far as engine wear... A few revolutions extra until you come to a stop is meaningless. But... I can tell you for sure as I enquired with a major race engine builder here... You are greatly REDUCING operating temps when coasting in gear. What's happening is that your cooling system... Water pump, oil coolers, etc are still working at speed. While there is no longer any high pressure combustion inside the cylinders that normally causes heat. So a rapid cooling effect takes place, heat is quickly scavenged out, and that is better for the motor than any "wear" taking place because your RPM'S are a bit higher for the next 10 seconds, until you come to a stop. The reduced brake wear is a bonus.

I think there was some misunderstanding. I favor going down through each gear unless you know you are going to stop, in which case I shift into neutral and let the clutch out and coast to a stop.

You are the first to tell me about the cooling effect of engine braking, but I have a question:

As everyone knows, if you are in first gear and you are traveling at say, 3400RPM, and instead of shifting to 2nd you need to slow down or come to a stop. We all know that if after you let off in 1st, the car will start to bog or jerk (even if the RPMS are high enough to not stall). Does this have to do with the vacuum effect you speak of? It always feels bad for the car to leave it in gear and slow down in first, so I always depress the clutch and slow down in neutral. I don't get this jerking/bogging in any other gear.
 
That's just be ause of the very low gearing of first gear. The braking effect of the drivetrain on the car is the greatest and it wants to slow IMMEDIATELY, and any raise in revolutions wants to accelerate IMMEDIATELY. So any back and forth makes the car jerk to a slow or jerk to change that momentum to acceleration. I don't think there is anything magical otherwise. It's simply the low gear ratio. There's nothing wrong with just pressing in the clutch when in first and coming to a stop. Nor is there anything wrong with being in any other gear and coming to a stop so long as you are not rowing down through your gears without having double clutched. The issue comes up when you were at high speed, you have decided to come to a stop, you are shifting from say 4, to 3,2,1, and you have not released the clutch in neutral to slow shaft speed. You are asking every synchro to work. The fact that your engine is not "attached" to the trans is irrelevant.
 
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I thought for sure the would be a ton of "I down shift rev match" because it sounds so awesome.

But yes, I do do that. :D and it puts a smile on my face every time. It will be infinitely more glorious once I get my test pipe in.
 
When I drive my Prius I always go extra slow to piss off people with loud exhausts like you.

.... And like myself when I am a different dude driving the NSX. :biggrin:
 
I've been downshifting alot since it's now a habit from properly breaking in the engine and it's good for the pistons since the act of downshifting creates negative pressure in the combustion chambers that helps draw up oil from the crank case to help lubricate the upper portion of the pistons.
 
I used to go down but then while at skip barber the instructor said something i found interesting...

downshifting 654321 (or name your sequence) to slow your car down for a red light? he asked what costs more: a set of brakes or a clutch?

I stopped downshifting after that, a blip then neutral for me...
 
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I used to go down but then while at skip barber the instructor said something i found interesting...

downshifting 654321 (or name your sequence) to slow your car down for a red light? he asked what costs more: a set of brakes or a clutch?

I stopped downshifting after that, a blip then neutral for me...

Did you take the class at Laguna Seca? I recall the instructor saying the exact same thing in my class there.
 
haha.....I dont believe you have a Prius.

No, just two girlfriends with them. I get 60 MPG out of them because it's the only fun thing you can do. That requires you piss a lot of people off but I've got it down pretty good.
 
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