ive been reading a couple of threads about engine braking. Never heard of such techniques because i never had a manual in my life. But it seems rather kool to slow your car down by downshifting in manualmatic mode and break at the same time. Some friends told me it wont harm the car and it also helps the brake pads. Others said its stupid because you can ruin the engine. Whats better>? engine braking or jus braking.

remember this is a AT

 

me using engine break all the time on my AT. TSX's breaking is too weak to me IMO.

 

You can damage an engine if you downshift at too high a speed in an MT (like, miss a gear and go lower than you intended). You cannot damage an engine with most AT's because they will not effect the downshift if the speed is too high. This holds true for the TSX.

Downshifting gives you better control and reduces the wear on the brakes. However, it is not a good habit to downshift at high speeds and send the RPM's towards the redline. I try to stay under 5,000 RPM's when downshifting. I am in Sport Shift mode about 98 percent of the time.

 

Brakes are cheaper than a transmission.

 

This is true and so it's just a matter of being careful when you do it.

Using engine braking is fine, when you need it, but you should not make a habit of it in regular driving since it does put unnecessary strain on the transmission (so by not doing it, you'll probably help the tranny last a little longer) but it is good to use in emergency situations or whenever hard braking is required.

And the next person that complains about the TSX brakes being too weak without trying new tires first gets trouted.

 

I'd love to read some proof that engine braking in an AT is going to do a single bad thing to the tranny. Everyone has his or her opinion, but nobody has ever offered any proof that he or she is correct.



(I do it, but not routinely)

 

I do as well, but like you only rarely. I don't think anyone can provide proof other to say that the tranny is being used under engine braking. The more something is used the more likely its to break sooner rather than later. Sort of like an engine with alot of miles.

 

meh, I'm not worried. I'd be more worried about wearing out a clutch in an MT than wearing the gears in my AT, and I used to engine brake all the time driving MT

edit: I don't share the complaints about the brakes though. My TSX doesn't stop as well as my riced up 240ZX in NFS:U2, but I'm not autocrossing and am content with them.

 

Is it the engine or the tranny that takes more of the strain? I'd think it's the engine, since the tranny does experience similar loads whether downshifting or accelerating anyway. But the car slows down because of the friction in the engine (not the tranny) caused by the change in gearing with the wheels still moving at the same speed as before (at the point of downshift at least), right? How harmful this is to the engine with occasional use I don't know.. Though I'd bet it's another case for synthetic oil

I do engine brake every now and then with some off-ramps, then accelerate out of the curve.. Fun to do it every now and then..

 

Engine braking is not hard on your transmission or engine. It takes far less effort to turn your engine over than it does to accelerate your car.

 

You mean far more effort?

 

Less... he means to turn you engine over while in motion

 

Nope, I think I got that right.

It's a lot easier for the momentum of your car to turn over your engine than it is for your engine to increase the momentum of your car.

 

Grew up driving a stick and got used to engine braking/downshifting; VW bugs have crappy brakes so I actually relied on it...well, that and turning.

I'm going with engine braking as being fine for the engine. Most MT drivers do it and don't even notice - I fail to see their cars engines dying any sooner than ATs.

Now whether the downshifting associated with engine braking (the SS basically) is good for the tranny, I do not know. In an MT you have a clutch that will eventually wear out from doing tons of downshifting, and even faster if you downshift really hard. What part of the SS would be the equivilant?

 

I do both? only time i downshift at high speeds is from 5th to 4th for a lil boost.

 

I don't know what you are talking about. The brakes on my TSX are like anchors. I've never had such good brakes on a car (try driving a Ford Expedition)!

 

Wear and tear apply to tires, transmission, engine, everything. I've been guilty of downshifting with AT transmission myself. I don't know much about torq converter and clutch and band, but I do know I can replace my pads and have the rotor resurfaced in an afternoon.

FYI. Auto-cross guys use brakes to slow down, then rev engine to sync with transmission. It's done for acceleration, not to slow down. Consensus is brakes pads are cheaper pressure disc on the clutch.

 

Professional racers downshift all the time to augment their brakes and so they can accelerate faster out of corners. IMO, you are doing no harm to your engine by downshifting but do whatever you feel comfortable with.

 

 

In the OLD days (and I mean OLD) engine braking was significant because brake fade was an issue and engine braking could extend the useful performance of your brakes. It was possible to fade brakes under hard road use, particularly drum setups.

Nowadays, brake systems are far more resistant to fade given huge rotors, multi-piston calipers, ventilated disks, better pad materials, and so on. When brakes became more resistant to fade, engine braking was unimportant.

As far as the performance of the braking system itself is concerned, the limiting factor on braking performance on a TSX is tires, not brakes. You can put your TSX into the ABS on any road, anywhere, anytime. If your brakes can lock the tires, they are more than powerful enough.

And engine braking would have the effect of shifting the brake bias forward (increased braking on the front tires since the TSX is FWD). There are many situations where that would be, ah, undesirable.

The post about downshifting to match engine speed is correct. In fact, you do that to make sure the engine DOESN'T affect braking balance. That's why downshifting is important to pro racers. The brakes can already stop the car faster than they can change gears. They will frequently skip gears changing down for this reason (ie 6-3-2).

If your TSX brakes aren't powerful enough, you might want to consider using them a bit sooner.

 

While I agree with you guys that engine braking doesn't do much harm you do have to admit that the engine is working more/harder under engine braking than it would be if you just pressed the brake pedal.

I'm not suggesting you shouldn't engine brake (Like I said I do) but you can't deny that wear are tear will be greater on a engine that is commonly used for braking vs one that isn't. Its the same as a car with 100,000 vs a car with 10,000. Chances are the car with more miles will require servicing first.

 

It isn't working at all

 

When you downshift do the RPM's not shoot up?

If they do then isn't the engine working/spinning? And if it shoots up to say 5000RPM then isn't the engine spinning faster than it would be without a downshift say at 2000RPM?

How could the engine not be working if its spinning? If its ON its working.

 

It is spinning, but it's not inputing energy into the process... at least that's my understanding.


jcg, who had an MT where he'd have to pop the clutch in first to start it sometimes

 

I'd like a explanation on this as well.

But to simplify things, an engine that is on is working harder than one thats off.

 

Say the engine shoots up from 2000rpm to 5000rpm on a downshift, how many times does the engine actually turn over before you continue driving again? Assuming it takes 5 seconds, that's only like 250 complete revolutions (rough mental math).

Food for thought...

 

So your saying its barely working harder?

I can't disagree but its still working more than an engine that isn't downshifting.

But I guess it doesn't make a difference in the end?

 

I use the engine when going down steep hills. This prevents fading by the brakes and keeps the top speed to a minimum.

Otherwise, it is cheaper to replaced the brake pads/rotors, so I don't recommend using the engine/transmission all the time.

 

You're right that an engine that is being used for engine braking is working harder than an engine that is just coasting. My point is that the difference is negligible. 250 revolutions isn't a whole lot.

Say you keep your car for 100,000km and over that time you average 60km/h and an average engine speed of 2500rpm (just numbers I'm pulling out of my ass):
100,000km @ 60km/h = 1666 hours of run time
2500rpm x 60mins = 150,000 revs/hour
1666 hours x 150,000 revs/hour = 249,900,000 revolutions over the lifetime of your vehicle

You'd have to make a lot of downshifts to put a dent in that number.

 

domn, who hates signs in Bolton that ask not to use engine braking.