Downshifting?

[markseven]

Hey Man! I saw your thread for the SSK. Search here, I think the guys here have used every stock Z shifter in their 30's.

Yeah, Lance I saw that thread - I'm still considering all options. What are you using? Stock or SSK?

[misterlance]

Hey Dude! :D The OP was inquiring as to whether one downshifts when coming to a stop. I agree with your statements but do feel engine braking for the sole purpose of slowing the car to a stop is conducive to premature drivetrain ware.

Hey Man! I saw your thread for the SSK. Search here, I think the guys here have used every stock Z shifter in their 30's.

And if you match your shifts, I cant imagine there being any premature wear. But I will say when I am cruising in traffic and coming to my hundreth stop light, I will only downshift as far as third (If I can even go that fast).

[doucy2]

i put the clutch in and go into neutral, then initate a gear after sitting at the light for a minute.

[vivalegreg]

oops

[markseven]

Downshifting is part of driving a manual transmission correctly. There are also safety concerns that make downshifting a good idea. Say a semi-truck loses its brakes behind you coming to a stop light. You could either be prepared or not.

Mainly its about keeping aware and prepared to deal with whatever may happen on the open road. You certainly want to be in the correct gear for your speeds when say using a highway exit ramp that goes from about 60 MPH to 25 MPH. And coasting in neutral or with clutch "in" changes the handling characteristics of cars, especially RWD ones. Making uneven sufaces and wet sufaces tretcherous if you dont know how to keep the driveline settled.

It is just safer to be in gear and rolling than to have your clutch in a lot or to roll in neutral. You also have more spontaneous control. And if you are concerned about MPG, Wise use of the throttle coupled with minimal braking saves MPG.

And furthermore, I have seen studies that compare fuel used at idle and the fuel used in a downshifting situation. And the thing is, when you are downshifting, the raised RPMs are caused by driveline momentum, not throttle or spark. Therfore the used fuel is virtually the same. You could turn your car off and still use the engine for braking.

Oh, and one more thing. Downshifting aids in engine cooling. Which of course is always a good idea with BMW cooling systems.

Hey Dude! :D The OP was inquiring as to whether one downshifts when coming to a stop. I agree with your statements but do feel engine braking for the sole purpose of slowing the car to a stop is conducive to premature drivetrain ware.

[markseven]

oh damn my bad, really? i never knew that...so are you saying when you let off the accelerator...your not using any gas? i thought engines had to inject fuel and a spark in order to rev....

What? If you are in neutral, the engine is at idle - if you down shift, your engine doesn't shut off, does it? Fuel is consumed in both scenarios.

No, silly! I never said coasting didn't consume fuel.

[misterlance]

Downshifting is part of driving a manual transmission correctly. There are also safety concerns that make downshifting a good idea. Say a semi-truck loses its brakes behind you coming to a stop light. You could either be prepared or not.

Mainly its about keeping aware and prepared to deal with whatever may happen on the open road. You certainly want to be in the correct gear for your speeds when say using a highway exit ramp that goes from about 60 MPH to 25 MPH. And coasting in neutral or with clutch "in" changes the handling characteristics of cars, especially RWD ones. Making uneven sufaces and wet sufaces tretcherous if you dont know how to keep the driveline settled.

It is just safer to be in gear and rolling than to have your clutch in a lot or to roll in neutral. You also have more spontaneous control. And if you are concerned about MPG, Wise use of the throttle coupled with minimal braking saves MPG.

And furthermore, I have seen studies that compare fuel used at idle and the fuel used in a downshifting situation. And the thing is, when you are downshifting, the raised RPMs are caused by driveline momentum, not throttle or spark. Therfore the used fuel is virtually the same. You could turn your car off and still use the engine for braking.

Oh, and one more thing. Downshifting aids in engine cooling. Which of course is always a good idea with BMW cooling systems.

[CleanAzzE30z]

this is gonna get good.

[vivalegreg]

In neutral, the injectors are firing a small amount of fuel to keep your car on.
If you downshift, the engine cuts all fuel (to slow you down). If it kept pumping fuel, downshifting wouldn't do anything, it would coast like a diesel.

oh damn my bad, really? i never knew that...so are you saying when you let off the accelerator...your not using any gas? i thought engines had to inject fuel and a spark in order to rev....

[markseven]

In neutral, the injectors are firing a small amount of fuel to keep your car on.
If you downshift, the engine cuts all fuel (to slow you down). If it kept pumping fuel, downshifting wouldn't do anything, it would coast like a diesel.

So what you are saying is the engine knows you have downshifted and cuts fuel delivery?

No fuel = engine not firing = no power steering, no power brakes...

I think you are mistaken

[vivalegreg]

What? If you are in neutral, the engine is at idle - if you down shift, your engine doesn't shut off, does it? Fuel is consumed in both scenarios.

your car is always consuming fuel when its on!!

when i am slowing my car down, i used to downshift all the time...till killed my new clutch....but that was in a 3000gt vr4...and improper shifting came into play too...
that car is awd too, just like my ix...and those vr4s tend to have a lot of tranny issues....so in my case driving awd cars i like to save my clutch as much as possible...also cause its not cheap replacing a clutch and i have yet to do one...and those drivetrains have lots of parts in em

my ix is being put together and i just got a new clutch installed....i believe i will not be downshifting very much and using the brakes more often...but i will still be practicing r3v matched downshifts..when coming out of corners and stuff or to accelerate if neccessary...but mostly will be using brakes until i can really get the downshifting, down


anyone here have a clutch stop ?? im pondering getting one....but cant really think how it works?? is it where you kinda set it at a certain engagement point and prevent the pedal from going all the way to the floor, for quicker shifts? wouldn;t that increase wear on a clutch?

also who here when comming to a stop, before rolling off, keeps their car in gear with the clutch pushed in...even sitting at a red light....does that create any wear on a clutch?? as opposed to just putting it in neutral...until the light turns green then putting it in gear??

[808BMW]

What? If you are in neutral, the engine is at idle - if you down shift, your engine doesn't shut off, does it? Fuel is consumed in both scenarios.

In neutral, the injectors are firing a small amount of fuel to keep your car on.
If you downshift, the engine cuts all fuel (to slow you down). If it kept pumping fuel, downshifting wouldn't do anything, it would coast like a diesel.

[markseven]

Accually your car will use less gas if you keep it in gear or downshift.
If you simply put the car in nuetral and coast to a stop, your motor is using a little bit of gas. If you keep the car in gear until you stop, your car isn't using any gas.

-erik

What? If you are in neutral, the engine is at idle - if you down shift, your engine doesn't shut off, does it? Fuel is consumed in both scenarios.

[uofom3]

i just about always match rev downshift at all times... and sometimes left foot brake for fun.

[erik325i]

All I know is that for a few weeks I stopped downshifting and I saved a noticeable amount of gas.

Mariano

Accually your car will use less gas if you keep it in gear or downshift.
If you simply put the car in nuetral and coast to a stop, your motor is using a little bit of gas. If you keep the car in gear until you stop, your car isn't using any gas.

-erik