plyboy-illest

dthis may be the dumbest Question but i dont knwo the answer to it so yea...

when downshifting do you waste alot of gas

Forseti

Don't worry about the gas...worry about the wear on the engine....

Try not to use the engine to slow down...use the brakes instead. Its a lot cheaper to fix worn out brakes than to put extra stress on the engine, and have to do engine repairs...

mugencivicsi

downshift is safe depending one at what rpm and how much..

Down shifting is better on breaks, it is normal to down shift from 4th to 3rd, from 3rd to 2nd when approaching a light, you will find your breaks last a bit longer.....


If you downshift and you are constantly at higher rpms (like over taking someone) it is also ok depending on how pay you beat on it..


only thing not recomended is downshifting from 2nd to 1st..... 1st is only a starting gear......


that should be right, but if im wrong someone else edit that....

plyboy-illest

yea i only downshift when comming to a light ralrly does the rpm go over 4k when i downshift...

sonyas_ss

i always downshift when approaching lights... rpms never (generally) break 3500 when i downshift.... i'm sure hoping it's all good!

plyboy-illest

thats what im hoping as well

SS33

mugencivicsi is absolutely right.

As long as you dont down shift into 1st while rolling you should be okay.

Now common sense must be used, like everyone else has said, keep an eye on your RPM's and only do it while decelerating to a light.

Zivnuska

I agree. Brakes are to slow down, downshifting is to get into the proper gear for acceleration. The exception is on an extended downhill grade--Ex. going down a mountain. In that case, use rev matching to downshift and then the engine compression will reduce the amount of braking needed. That is why you often see signs suggesting "use lower gear" on a long downhill run that might otherwise overheat the brakes.

https://www.cobaltss.net/forums/show...055#post433055

mike25

why is downshifting from 2nd to 1st bad.....i always downshift from 2nd to first and my uncle that has been drivin a vette for years has been downshifting from 2nd to 1st and said it doesnt hurt it any???.....

SS33

As was previously stated first is a starter gear, and will have different pitch and entry angles for the gear teeth. Also 1st gear is so short in our cars that it wouldn't do alot of good in slowing the vehicle down, and would be more prone to over-reving if downshifted to.

This is why alot of manual vehicles used to have the 'granny gear' for first, which cannot be shifted into unless you are moving slow enough (or not at all in some cases)

And if you are moving at a low enough speed in second to drop to first without pegging the redline (which equates to ~15 mph MAX), than you're slow enough that engine braking shouldn't be required anyways.

All the other gears are designed to be entered from either side (downshift or upshift, so this doesn't place much additional stress on the gear itself (at reasonable RPM levels)

This isn't to say that you can't downshift to 1st, just that doing so involves more risk than downshifting to any other gear.

Make any sense? Kinda hard to explain, but search for pictures of starting gears compared to drive gears and look at the pitch and entry angles of their teeth.

(Also your uncles vette probably isn't handicapped by the rediculously short first gear that GM gave us)

Hope that kind of explains it.

OniMirage

I would rather pay for breaks than a new part for the engine should something go wrong. I downshift let it be known though I rarely downshift lower than 3rd and only do it coming off the freeway. If I need more slow me down ability then I will downshift to 2nd but I don't normally find myself in such situations though they have happened.

SS33

Good points^^^

The only time I really ever use engine braking is if I'm speeding and see a cop, especially if he's going the other way, or I pass him. I'd rather use the enine to slow me down, than be obvious and start hitting my brakes.

In my experience, hitting the brakes almost always equals the cop writing a ticket.

cawpin

Using the engine to slow down will not hurt the engine, as long as you don't over-rev it.

"Granny gears" are not used for normal driving. My 1985 Chevy K20 had a granny gear. The transmission was a standard Muncie 4 speed but had a 6.33:1 first gear. (It is still a much sought after transmission for trail trucks if you want a manual.) You only used 2-3-4 for regular driving. The stick was labeled L-1-2-3. If its high enough to use for normal driving it isn't a granny gear.

OniMirage

There in lies the problem though as there is a possibility that this can happen. Just be careful and think before you act and you will be fine.

SS33

That is correct, and I had an 86 K20 that's why I used the example, lol

I was just using it as a parallel to explain the concept of a starting gear. I know we don't have a granny gear, but our first gear is short enough to be compared to one. And to show why it is a bad idea to shift into first gear while rolling.

SS33

^This pretty much sums up this entire thread

GStam66

wait, when approaching a light, cant wou just go from say, third to neutral, and then apply the brakes? Then when the light hits green, go to first, and go?

Cause if you're going 55 or 60 mph, and the light turns yellow, and you have to stop fast, I dont think youll have time to downshift from 4th to 3rd to 2nd.

OniMirage

normally you wont have the time to do it so just go to neutral and apply the brakes.