To Engine Brake or Not To Engine Brake

If you are really good you can upshift through all the gears and downshift through all the gears (after you get going) with NO clutch at all. I have done it in many cars and trucks. the clutch cable broke in my 1972 volvo and i drove all the way home in the city...!!

Arent brakes cheaper than clutches? Why would you want to destroy your clutch? Stop doing that my man, brakes are cheaper.

Rob

I don't understand how engine braking destroys the clutch? In fact, maybe I don't understand what is meant by engine braking? Please elucidate.

...Ron

It's cheaper to push the car than to use the engine.

Besides, why would downshifting cause significant clutch wear? It wears a heck of a lot less than starting from a stop - and we don't even blink about doing that.

Ron Ginter wrote in news: snipped-for-privacy@4ax.com:

It doesn't. If the engine & transmission speeds are matched before releasing the gas pedal there will be virtually NO wear on the clutch. Engine braking is a great way to prolong brake life. Especially if you frequent the mountains.

-S.S.-

Some folks may wear their clutches when they downshift if they don't match their engine speed by blipping the throttle.

So for folks incapable of doing that, I suppose they shouldn't engine brake. For the rest of us...

nate

Modern advanced driving teaches 'brakes to slow, gears to go'. This is fine as far as it goes, but there are certainly instances when changing down through the gears will improve stability and increase safety....particularly when descending steep hills. I would also agree that it is a must on slippery surfaces, where you want to use the brakes as little as possible and only very gently.

No question of clutch damage if done properly.

David Betts snipped-for-privacy@motorsport.org.uk

Do you realize your post is just a couple of non-sequitors?

IMHO there are no differences between applying the brakes and downshifting in an AWD car. Both apply stopping force to all four wheels - I would think the brake pedal allows more control to the amount of braking force.

I think the misconception of the utility of engine braking for cars comes from people seeing truckers doing it. Truckers downshift on long hills with heavy loads because they have enough momentum to cause brake-fade by the time they get to the bottom of the hill.

RWD cars get a bit of "stability" because downshifting only applies braking to the rear wheels. With big heavy V8 engines over the front wheels, applying the brakes can cause you to fish-tail.

God help you if you downshift in a FWD going down a slippery hill - spin, spin, spin!

For those who know how to double clutch on the downshift, you get the smoothest connection of drive train and engine. On a snowy downgrade, with AWD you get smooth engine braking without pitching the vehicle forward, as happens when you use the brakes.

Unfortunately, my spouse has warned me that my next car must be an automatic. Ugh!

But even with an automatic, when downshifting, you can gently "feather" the throttle as you downshift.

Thanks. I have driven standard transmissions all my life, have used engine braking all my life, and have not had clutch problems. I figured that either the 'clutch damage' statement was wrong, or there was a new definition of engine braking.

...Ron

As a newly licensed driver in '52, I taught myself that trick in a Studebaker pickup. You had a practical purpose for doing it, whereas I was just entertaining myself while delivering items around town.

BoB

But brakes are biased to the front (60/40?). You'll tend to slide the front brakes on a slippery stop.

jw milwaukee

In my own opinion, i live in a town where it is either rainy, or snowy / icy, so engine breaking has been very useful. for instance, i was driving home last night, and rarely had to use the brake pedal. i control my speed mostly with the accelerator and gear im in. there is a stretch at the end of the highway where you go from 55 to 40 to 35, over a bridge, and back to 40, and it just came natural to use engine braking and gear shifting to get through that area than use the brakes going through that area and over the bridge twice a day.. i have always been told that there is no problem 'letting the engine do some work'..

just my opinion JB

The pressure on the disks is even, but the front has more stopping force because of the weight shift. This happens with engine braking too.

On Sat, 07 Feb 2004 17:50:43 GMT, snipped-for-privacy@aol.com (J999w) wrote in news: snipped-for-privacy@mb-m03.aol.com:

Brakes are biased because weight shift under braking puts more weight on the front wheels even in a car with 50/50 static distribution and because locking only the rear wheels causes an uncontrollable situation for many drivers. Making sure the front wheels lock before the rears is a basic form of stability control.

As for the comment someone made about brakes pitching the car forward where engine braking doesn't, that doesn't hold water. The pitching, or weight shift, happens with either. The only difference may be that using the brakes creates more stopping force which will obviously produce more weight shift.

Brakes are alot cheaper than a clutch. For those who do their own work, very much cheaper. Engine braking is completely unnecesary in modern cars. Their capacity to perform is much greater than cars of thirty years ago. Downshifting to put the car into the best gear after braking is a better reason.

The Forester manual suggested using engine brake more often.

Actually, you can downshift to engine brake - using the clutch - without overtaxing it. Just match engine revs before releasing the clutch, so that the engine is already going the correct speed for your new gear and road speed. Wait until the clutch is fully released before lifting the throttle to provide engine braking and spare your brakes. (Though I'm not sure that sparing the brakes is a good reason to employ engine braking. I prefer to use a lower gear in traffic because it gives me better control over my speed with only the throttle. The trade-off, of course, is increased fuel consumption. But with gasoline cheaper than bottled water here in the 'States...)

What destroys a clutch is excessive and prolonged speed differential between the two plates. Raising engine RPM with the throttle to what it will be with the clutch released *then* releasing the clutch doesn't cause any additional wear. OTOH, shifting into a lower gear then letting the clutch force the engine up to the appropriate revs for the new gear will definitely increase clutch wear. As long as the speed differential between the engine and the tranny is minimal, so will be the wear on the clutch.

Actually, one should *always* rev match when downshifting, if only to make your driving smoother and thereby reduce neck strain in your passengers :-). And I always try to double-clutch my downshifts to save the synchros as well, but that's probably a bit over-the-top in a modern manual-transmission car. Old habits, you know. I never got very good at using the heel and toe of my right foot to operate the gas and brake pedals at once, so I don't bother with the double-clutching if I'm on the brakes while downshifting. The only time I do the heel-and-toe thing is accelerating from a stop on an incline when some dork pulls right up on my bumper. Though I understand I won't have to do that with my new Subie, since they all have that neat "hill holder" feature.

And the only time I've ever shifted sans clutch is on a motorcycle. I've never been brave enough to try it in a car. I can match revs pretty well, but I don't get it perfect every time -- which is what would be required to shift without the clutch. I suppose if I was in a pinch -- like with a broken clutch cable -- I might give it a whirl. But I've fortunately never been in such a pinch.

- Greg Reed

... or drive a stick ...

- Greg Reed

Do you even know what you mean?

David Betts snipped-for-privacy@motorsport.org.uk