I don't get why some people say you should never use engine braking. Can anyone tell exactly how this is damaging to an engine?

I personally like to use engine braking to slow down my car when moving in traffic that's slowing down and speeding up. I also like to use it to balance my car when making a turn and to maintain a steady speed in long down hill roads.

 

There's nothing wrong with it. As long as you don't pop it into 2nd while when you're on the freeway doing 90 you'll be fine. Just be sure to use good judgement and don't rev your engine too high, obviously.

 

I don't have much engine breaking anymore because of my new head, but I do spend a lot of time in the upper RPM end of my RPM band, even though it's on the street.
I don't see any reason why it would harm the engine. Like others have said, just don't drop it into 2nd at 90 MPH and expect it to be subtle. So long as you're rev-matching your downshifts, it shouldn't matter what the RPM's are at .

 

I use the engine to go and the brakes to stop. Anticipate and coast to stops as I can. Figure a brake job is far cheaper than an engine overhaul-IMHO.

 

Engine braking does NOT damage the engine unless you over-rev. Engine braking also gives you safer, more controlled deceleration than coast braking. Ask any professional driver.

 

My understanding is it's not so much damage to the engine, but unnecessary wear on the clutch if you downshift without rev-matching. The clutch is more expensive to replace than having a brake job done.

 

if you aren't rev matching or double clutching you are wearing out your clutch and synchro's, un-necessarily. For the most part, stick to brakes braking... and engine going.

 

FYI, I think some of the confusion on this topic comes from the difference between the concepts of "downshifting" versus "using your Engine to help breaking". They have very different purposes:

When I was first learning to drive, I was told (incorrectly) that downshifting was the same as Engine breaking, i.e. you downshift without giving it more gas to cause the RPMs to shoot up and thus help the car to decelerate without having to press the brakes as hard. This theoretically reduces wear on the brake pads, but at the cost of significantly shortening the clutch lifespan.

True engine breaking is mainly relevant to big trucks with massive engines that have significant rotational momentum that can really help the deceleration, and have the necessary massive clutches & transmissions to handle the additional stresses. The Mini's lightweight 4-cylinder engine & relatively high gearing (compared to a truck) means that all you're achieving is wearning out the clutch quicker.

Once I started doing track events, I learned that the real reason to downshift (for regular cars) is completely different. At some point while you are breaking going into a corner the engine RPMs have dropped too low. So you have to change gears to *match* the desired RPM range to the new speed. You do this by downshifting while "blipping" the gas (heel-and-toe). The "blipping" is very important because it matches the engine RPMs to the wheel speed so there is no jolt as you release the clutch.

With correct downshifting, you are purposefully doing *all* the breaking with the breaks and minimizing the force applied to the engine and transmission. A good race car driver can downshift in a corner so well that you don't feel *any* jolt at all. This keeps the car smooth & balanced.

I highly recommend learning to heel-and-toe. It extends the lifespan of your clutch & transmission...and it sounds really cool!

Make sense?

 

I think the OP is wondering whether it is ok to let off of the gas pedal and let the engine "brake" the car when coming to a stop. Not necessarily down shifting, just letting up off the pedal. There is no additional wear and tear of the engine in this situation.

 

In either case, engine braking is supposed to be used for better control and the logic of "don't use it because it will wear out" is faulty. After 106,000 miles, I just sold my Mazda, which has been engine braked its whole life. Clutch never needed work of any kind.

 

This is EXACTLY how it should always be done! He is not speaking about shifting he is talking about a very obvious effect that remains lost on about 90% of drivers I witness.....That if you simply lift off the gas that you slow dramatically egnough to avoid using brakes at all in most traffic......I see brakelights bliping all over the freeway for NO REASON! These are the people who are shocked that thier pads only lasted 20k miles......Unless there is an accident or hazard....that required a drastic rapid drop in speed you should never have to use your brake pedal......But because nobody drives like this you get all these reactionary brake lights to one person who used their brakes for no good reason.
Engine braking is not damaging, and is not disputed
downshiting to engine brake is very debatable but not what is being discussed here

 

If engine braking was harmful I doubt MINI would have programmed it into the Sport mode of my MCS Automatic. When in sport mode it uses engine braking.

 

Just to clarify: I agree with the other posters that it does not help to keep the clutch pedal depressed while braking (or at any time for that matter). So yes, technically the engine is coupled to the wheels while you are breaking.

But the momentum of the engine is not really helping the breaking in any significant way. The reason to not hold down the clutch is because it causes unnecessary wear on the spring mechanism of the clutch. This is the same reason you should shift into neutral while sitting at stop lights (although there are other pros-and-cons to that).

BUT once the RPMs drop below about 2500, you should definitely downshift even if you think you're coming to a complete stop. The worst possible scenario would be if you suddenly need to accelerate (e.g. because someone is about to rear-end you) and your RPMs are too low & you stall.

 

Also to clarify... I engine brake all the time--I bet it confuses whoever's behind me when they see me slow down without any brake light indicators. I only wanted to suggest that the reason why the OP heard engine braking was bad was because of the downshifting-without-rev-matching confusion.

 

True, if you're just talking about small speed adjustments then braking seems unnecessary. Most of the time I've seen that people resort to braking on the freeway is because it takes them too long to react to the change of speed of the car in front of them. So it's too late to make a gentle correction.

 

Actually it does more-or-less the equivalent of a heel-and-toe. It increases the RPMs *before* reengaging the trasmission.

 

Ok, this raises an issue I'm really curious about other people's thoughts on: (and I *really* don't mean this in any kind of derogatory way)

To me, part of the reason for brake lights (and all signal indicators) is to provide information to other drivers around you about what you *are* doing (i.e. decelerating) and what you *will* be doing (i.e. turning). If you are chaging speeds significantly (i.e. say more than 5mph) without signaling that to the other drivers around you, then isn't that potentially dangerous?

And yes, I realize that it should be very easy for just about any car+driver to make a simple 10mph adjustment...even if it takes them a while to react. But given the number of cell phone drivers nowadays, it seems like the more visual clues they get (preferribly the big, red, flashing kind) the better.

Yes/no?

BTW, how are you decelerating and simultaneously rev matching without depressing the brake?!? edit: I guess if you were slowing down *very* slowly you could achieve that...

 

I wholeheartedly agree. I use the brakes if I'm making any large deceleration maneuvers for precisely that reason. But for making minor speed adjustments on the highway? I can control my speed better with the throttle.

But I see brake lights for what I consider to be minor speed adjustments because either it's hard to control one's speed in an automatic or because people's driving habits are such that they accelerate until they're too close to the person in front and then brake... maybe that's another topic, though!

 

Makes sense.

And I apologize that my question was a bit OT. I should start a new thread for that...

 

One point I would like to add is that when cornering, or really at any other time, if you have the clutch depressed, and out of gear, your DSC wont work properly. When slowing down for a curve , you will most likely have to downshift. You want to make sure you get the clutch released before the corner. This is when the heel/toe is really helpful. I just watch my rpms and tap the gas a little before I let out the clutch.

Boy, driving a MINI can really be a lot of work . Its not one of those cars you sit back, steer with your pinkie and ride the brakes

 

a few things... you drive a small car. Think of the mini like a motorcycle. People will be looking right at you and look right through you... aka not see you at all.

Brake lights are a very smart idea to accompany your deceleration. I am guilty of not doing so very often and it always seems i see a chevy bowtie on a large pickup truck approaching fast every time i just let the engine come to a stop.

As far as engine braking to come to a stop... ie doing it and downshifting. New age cars are built with a sort of slop factor built in. AKA synchro's etc. The more and more you tune your vehicle and start to drive it hard like a race car... the more and more you have to adjust your driving techniques to prserve both your car and your roll speed. Downshifting to come to a stop, while it sounds cool and may be fun... it does not extend the life of your drive train components.

As a rule of thumb the brakes are very cheap part to replace in comparison to gear box and clutch. They were in fact made in a modular fasion so that you can do just that. It is my judement from these engineering ques that decides how i drive my car and what parts I replace often at my expense... I'm sure in a DD/lighty driven car this isn't so much of an issue... but in a car that is driven like mine... I have to watch every little variable.

my only background for compaison is my, 2 alfa gearboxes, and my 1 subaru gearbox. which in my racing career were swapped often as they went bad.

 

I've been downshifting and engine braking since I started driving well over 40 years ago. Done correctly there is minimal wear on a clutch, in fact in vehicles ranging from motorcycles to Honda Civics to 15 ton trucks I have yet to replace a clutch in any of them.

I don't expect to in my MINI either. If I do, I reckon the MINI has a weak clutch to start with.

 

By far one of the weekest I've ever seen on a performance production vehicle. will barley stand much more then stock tq.

 

Well when I have to downshift I'm rev-matching every time. Either by blipping the throttle and downshifting, or heel-toeing. And like others pointed out, I also use engine braking to make minor adjustments to my speed, so no wear on the clutch on those instances.

I personally don't like the idea of coasting. With the engine and tranny engaged in the right gear I feel like I have way more control over the car.

My current car is a 5 speed, so this is one typical way I use engine braking. Going on the hwy in 5th and I'm approaching my exit, I'll usually rev-match to 4th just as I entered the exit lane. Then I'll either heel-toe to 3rd or 2nd, depending on the speed posted, and let the engine braking help maintain my speed as my going downhill.

The reason I asked this question is because in the street I see a lot of people who don't rev-match anything. I can hear them pop the clutch and coast through turns and other stuff where I would normally either leave the tranny in the same gear or downshift by rev-matching or heel-toeing. So I was wondering if maybe there's something wrong with my driving style that I should fix before I get my Mini.

Also, I never downshift and use engine braking to bring the car to a stop. I'll either use engine braking to make minor speed adjustments, maintain a steady speed (downhill roads), or combined with the brakes (ie heel-toe). When coming to a stop I'll press the brake pedal, I'll leave the tranny engaged in the same gear I was in, then when the tach shows 1.5K RPM I'll pop it into neutral and finish braking.

 

You should keep on keeping on, brakefade. When I was taught to drive a manual, I was taught rev-matching was part of it. Never considered it an option.