Is engine braking good or bad on the engine of our car or any other car? Why?
Feel free to state opinions, ideas.
Al
Depends on how you define engine braking. Engine braking is not only helpful, but often a good thing.
If you are cruising along in what ever gear, and you let off the gas (don't touch the clutch) you are engine braking. This uses NO MORE gas, does not wear on the clutch at all (obviously), and it saves brakes. No real disadvantage.
If you are refering to doing it while coming to a complete stop, there is a lot of debate. My stance, it is good because it ASSISTS the brakes in doing their job and provides no additional wear/tear/etc. If you are talking about downshifting, this is very debated as well. I downshift, and I do it quite well by rev matching. There is little additional wear, and I feel that that additional wear makes up for the brakes that I would be using instead.
I common thing that I hear that drives me nuts is people that say "brakes are cheaper than clutches." Sure, this may be true. I know several people that have had clutches last 150000+ miles and they downshift all the way through the pattern on every stop.
My biggest thing, automatics downshift and a lot of people don't know that. Brakes are made to be used in conjunction with the engine. So pushing in the clutch and using all brakes is going to wear them out real quick like.
"The Blue Bullet"
An automatic transmission won't downshift when you're coasting down a hill in gear until you're doing maybe 20-25 mph, engine braking won't help much at this speed anyway. I hate when people talk about 'gearing down' in a stndard shift car. Look, you're not an 18 wheeler, you don't need to gear down when you're coming to a stop, the only reason you'd need to gear down in a standard shift car is if you're going down a steep hill, coming to a stop from a real high rate of speed or you're carrying a heavy load. Downshifting in a standard shift tranny will cause a lot more wear than just on the clutch, the synchros will be doing a lot of work unless you double-clutch it before you downshift. Like I said about an automatic tranny, it won't downshift on deceleration til maybe 20-25 mph so you're brakes are still doing most of the work.
Note that whether you're downshifting or not, you should NOT just push in the clutch and then use the brakes to stop. The clutch shouldn't be pushed in (unless to downshift) until your RPM's are under 1000 or so.
Even if you don't downshift, the engine is still helping you to stop and you SAVE gas by doing so. If you push in the clutch, the engine needs gas to hold idle and you use more brake power to slow down. If you don't, the engine will cut fuel because it senses 0 throttle and higher than idle RPM's.
I downshift most of the time. As mentioned, if you do it correctly there's very little if any extra wear on the tranny. Beyond stopping more efficiently, I like the fact that should the need arise, I have the option of accelerating and being in the correct gear to do so. If you're still in 4th and are coming close to stopping and then mash the gas pedal... you're going nowhere fast.
Edited 1 time(s). Last edited Tuesday, August 01, 2006 5:03 AM
When I'm slowing down, I just leave the tranny in 5th and use the brakes til I'm going about 35-40 mph, then I push the clutch in and let the brakes do the work.
I suppose the synchros are doing "a lot of work," but is that bad? There is no more wear on a synchro from a upshift to a downshift. Synchros are doing there job, and downshifting is not ABUSING them, it is USING them. The previously mentioned drivers whom I stated have gone over 150000+ miles on a clutch, have yet to replace synchos either. No double clutching, just rev-matching.
Don't push in the clutch until your engine is lower than 800 RPM? Thats on the verge of bogging it down... I would say no lower than 12-1300. Not only does this give you some room before stalling, but the owners manual suggests this as well.
So you say engine braking is necessary from 55-60 down to 35-40, but why is it unnecessary from 40-0? According to you this is when automatics START helping the brakes. BTW, my parents hyundai downshifts to 4th (unlocks TCC) at 50ish, downshifts to 3rd around 35, 2nd around 20....sounds a bit like me downshifting in my cavi....except I don't downshift to second usually. I will admit this is because the 1-2 synchro in my car is a tad slow, but that has been the case in all manuals I have test driven. Obviously it is not from my driving because I just got this car.
"The Blue Bullet"
i down shift most of the time or i just take it out of gear and coast to the stop lights or what ever i dont see any harm in that
Jon wrote:Don't push in the clutch until your engine is lower than 800 RPM? Thats on the verge of bogging it down... I would say no lower than 12-1300. Not only does this give you some room before stalling, but the owners manual suggests this as well.
Yeah, 800 was a bit excessive.
I fixed it.
Gets the point across though. You don't clutch in until you have to. You don't just do it while you're slowing down for the heck of it.
My view on the good for your transmission or not view is that if the trans can move the car it should be able to hold up to stopping the car.
Also brakes are cheaper to replace than clutches, but if your rev matching on your downshift its a mut point.
For the record I don't let the clutch out but I do go down thru the gears for the consolement that if traffic starts moving again before I reach the light I can just let the clutch out and accelerate.
-Chris
IamRascal wrote:My view on the good for your transmission or not view is that if the trans can move the car it should be able to hold up to stopping the car.
Also brakes are cheaper to replace than clutches, but if your rev matching on your downshift its a mut point.
For the record I don't let the clutch out but I do go down thru the gears for the consolement that if traffic starts moving again before I reach the light I can just let the clutch out and accelerate.
Food for thought here. If you are going to use the argument brakes are cheaper than clutches, I'd like to use the argument clutches are cheaper than synchros. So you are using all brakes to stop the car to save your clutch, but you are still rowing backwards through the gears which is wearing on your synchros. Seems to me that is unnecessary use of your synchros if you aren't going to use the gear. Unnecessary use = abuse
j/k, but you sorta get my point?
"The Blue Bullet"
I downshift when coming to a stop, most of the time. If I see a stop up ahead, I'll slowly downshift through the gears all the way down to 2nd gear...if I see a stop late, or someone cuts me off at the stop (happens wayyy too often) then I typically just push in the clutch and the brake...
