faster deceleration method hurt tranny/engine?

[Rapidito]

I was reading somewhere that in order to decelerate faster and with more control, one should shift down. Say you're going 95 mph and you have to decelerate quickly, you'd shift down to gear 4, if you so happen to be on 5, or 3 and just brake accordingly to not lose control. However, since you shift down, doesn't the engine or tranny absorb some of that momentum? after all that energy has to go somewhere. If so, could that cause some forces on the gears or engine that could cause harm?

[sublimewls]

i would judge by feel... since neither of my parents teached me how to drive a stick, i had to learn by myself. I would use the BRAKE(not handbrake) doing 95 then maybe when about 70-75 go into fourth slowly... you might burn your clutch a little. But yea... i think if you down shift doing 95 and just drop it into fourth is any easy way to grind the gears. I'd say it depends on the situation... like if you have bad brakes (which i have experienced) then ya go into 3rd (if u think you are able to do so).

[t0p_sh0tta]

Brakes are much less expensive than motors, trannies, and clutches. You won't ruin your car downshifting unless you drop it into too low of a gear. All it does is cause excess wear and tear.

[civickiller]

the motor isnt made to be a brake, thats what your brakes are for. use your brakes

[Milliardo]

Use your brakes first. Engine brakes aren't used often, except for emergency purposes.

[sageuvagony]

I down shift alot on my tranny but im guessing Im gonna mess it up sooner or later right? and If I keep shifting my auto like a stick.. why would my tranny break? how?

[Smoakie976]

Okay I was taught to down shift by my parents and do not think that It will hurt your car unless when you down shift you go over red line and then you could blow your engine! So if i keep down shifting then I am going mess up my engine?

[lewdaka03]

well if your going 95 i would say you should down shift but like some dumbasses (not you) do they accelerate pushing there engines to the red..... i suggest you brake slow to lower rpms then shift down and apply brakes.. do you have stock clutch??? does it have lsd???

[93speed]

Personally, I do it all the time. Its a bad habit I got into while driving in the snow and ice. In that case its well worth the chance of breaking something rather than locking up the brakes and killing myself or someone else or totalling my car. I've done it in my accord for the 2 years I've driven it and I've had no problems with the clutch/tranny. Nor have I heard any bad stories about people having drivetrain wear.

Its all theory. I've yet to hear concrete proof to back it up. Its like taking your engine to redline everytime you shift. People say it will wear your engine faster, but nobody has proof of anything.

[Rapidito]

I have stock everything on my car. I downshifted a few times after going fast to see what would happen and I felt no serious harm to my car. Then again, I don't know for sure what's going on in the engine or tranny at that time but from my experience it went ok. I didn't redline the engine or anything I just accelerated to a controlled, fast speed on the interstate and shifted down to a reasonable gear, 4th, and immediately applied the brake (gently) and the car slowed down with a lot more control than if I had just used the brakes alone. If I ever have to brake quickly I plan on doing this again because I've had to brake suddenly just using the brakes and I've almost lost control.

sage: I suspect that the tranny can be messed up by down shifting because all the car's momentum is transmitted to the motor through the transmission gears. Again, I'm not 100% sure. As we can see by the other responses, some people downshift regularly and don't have any horror stories.

[wheel1856]

I, much like 93Speed, am in the habit of downshifting when I break, its second nature now, when I break, I down shift. I find that you can control and stop the car much faster. I've been doing it for years, no problems as of yet. I see it as being on the same level as double clutching but for breaking to stop not turn and haul ass.
I wouldnt suggest going from 95 in 5th to 2nd immediately. In fact, very, very rarely do I ever use second when breaking like that, I usually hit 3rd all the time, and then second if Im in trouble.

[Milliardo]

The problem with those who came from auto to manual is shifting, especially downshifting. Some, as I have seen here, downshift before they brake, which is quite improper. Downshifting is used only after you have applied the brakes and want to go to a lower gear, and in extreme cases for an emergency. But even in an emergency situation, the rule must be that you apply the brakes first before downshifting. Downshifting is only a measure done when braking is not enough in an emergency.

The method of downshifting is such: brake, clutch shift down, release clutch, accelerator (or else maintain speed, or hold brake if trying to slow down). Depending on the circumstances, you wither accelerate again, maintain present speed, or continue to hold the brakes. Note that continious shifting will wear out your transmission sooner.

[94tegRS]

most people I know do it and Ive personally done it on every stick ive owned, but I do start braking and then downshift, but never let my rpms go above 5500 in my integra, in certain cases I had to downshift quickly and put it up to about 6500 in each gear just to avoid hitting something, but neither me or my friends have had problems cuz of using the engine to help in braking (not as the brake)

[ROKnight]

Downshifting is a standard practice and by most auto manufacturers actually recommend it for decelerating. If you read into some manufacturers' manuals, it will actually instruct you to downshift to slow down.

Jae Hoon

[Rapidito]

I'll keep that in mind Milliardo. It does make sense, now that I think about it, to brake first.