Slowing by Downshifting

Someone in the e-brake thread mentioned being taught to slow down by downshifting, rather than using the brakes. A couple of friends of mine do the same thing. At first I was surprised, but their response was that if done properly, it doesn’t damage the engine. I do it to slow down on ice, but wasn’t exactly taught it, so the concept I have of it is that you should have your clutched (ie neutral) RPMs match where they will be when you release the clutch (similar to upshifting, actually).

I understand why this method doesn’t “damage” the engine per se. However, it seems to me that it puts wear on your clutch. The same way that not slamming on the brakes when you want to stop isn’t “damaging” to your brakes, using them in a controlled manner still puts wear on them. Given the choice between putting wear on my brake pads and putting wear on my clutch, I’ll go with the cheaper-to-replace option every time.

So am I wrong in my thinking, or is there something I haven’t thought of? Is there a reason to use downshifting as your primary method of braking?

Honestly just use your breaks people say oh well it saves your breaks! Breaks are cheap and dont have to be replaces all that often. I rather put less stress on the tranny and engine then the breaks doing what they were designed to do.

Depends. If I’m slowing down from highway speed, and I know I’m going to be stopped for a while, I’ll just brake until I’m doing less than 20kmh then clutch and knock it into neutral. However, if the traffic could start moving again at any time, I’ll downshift too, so that I’m already in the correct gear if I have to accelerate. There are other scenarios too, such as slowing for a tight corner. Also, it’s more FUN.

Brakes are a lot cheaper to replace…I shift into neutral and use them.

Unca Cece

Tom and Ray say, use the brakes to slow down normally, that’s what they’re for. Downshifting for long downhill grades is a special case, and they recommend that because over-long application of the brakes can result in overheated brake fluid, causing total brake failure.

And he’s wrong, or at least only presenting part of the case, when he says “You have more control over the vehicle” by downshifting. Being in the habit of braking means your foot is in the right place to minimise reaction time should you have underestimated the necessary deceleration, or if somebody ahead hits the brakes hard for some reason.

Can someone explain what the advantage of this is?

Why wouldn’t I put the car into neutral (or at least have the clutch in) when I need to slow down? I get the in case I need to accelerate part, but a) it doesn’t take that long to throw it into gear if you’re in neutral, especially if you still have the clutch in, and b) how will I know what gear I need to be in if I do need to suddenly accelerate?

F’r 'xample, if I’m tooling along in 5th gear on the hwy, and I start braking down to 15mph like Cecil recommends (or possibly the car talk guys, it’s a bit unclear from the article), maybe once I get down to 30mph I notice a truck about to kill me from behind. Having left the car in 5th like is recommended, I now have to shift out of 5th and into 3rd to get any kind of acceleration. How is this better than putting the shift in neutral in the first place?

Yeah… sorta… maybe… kinda. I don’t know. It gets down to the fact that there are two feet and three pedals, and most folks don’t do heel-and-toe stuff.

Sometimes, I have done pure downshifting - just for laffs. For example, if i’m the only car on a motorway off-ramp, I might try it for fun to see if I can stop only doing that. Generally though, my use of gears to slow would be only supplementary to the brakes (ie. my right foot is on that brake pedal anyway), and I don’t go down through all the gears. I might go from fifth to fourth, and then hit second for a few monents. Depends, really. I certainly don’t drive it like a semi-trailer, and wouldn’t dream of using first*.
In general, if there’s a need for sudden braking, my foot is covering the pedal, and I’m onto it.

  • I know a bloke who went for a light truck licence, and was failed for not using first gear to slow. The truck was small, and it was unladen. He used first on the next attempt because he knew the examiner was looking for it (had to use every gear), but he said it was unnatural and silly.

That’s a very good question. I think the main reason is that even a high gear will provide some engine braking assistance, and since you’re in that gear already, it won’t hurt the clutch any to stay in it.

There is another reason but it’s one which I’m hesitant to give because it’s hard to defend with cites or anything - driving in a car in neutral at speed just feels wrong. There is a sense of lack of control. If you have to corner, the car feels like a houseboat as it seems to roll away from the corner rather than squat into it.

Would it be easier to lock the brakes in neutral? (Ignoring ABS for the moment)

On most modern cars, this will give you a slight advantage in fuel economy. When the engine is idling with the clutch in, the engine consumes some fuel to keep idling. If you completely let off the throttle while still in gear, the ECU knows to shut off the fuel injectors completely, consuming no fuel at all. You can test for this with either one of those analogue fuel economy meters (rare) or with an exhaust gas temperature gauge, which will show a lower temperature in gear than out, upon deceleration.

Here’s an aside:

My brother claims to have seen someone driving an automatic trying to stop in a hurry by slamming on the brakes, locking them up, then quickly throwing it in reverse, then flooring the accelerator. He said it make a lot of smoke, but it did the trick.

I think he was pulling my leg.

That’s what brothers are for, to keep your bullshit meter working.
Occasionally I’ll drive a car in a somewhat punishing fashion. Downshifting hard such as into second at 55 or 60 will drag the rear wheels, not locked up but not keeping up with the speed of the car. This does several things.

One it provides a lot of rear wheel braking to accentuate any regular braking which is proportioned to the front wheels.

Two it helps to set a drift if that’s what you wish.

Three it sets the drivetrain ready for full acceleration say if you slowed for a short sharp curve and were ready to power out.

or Four…Chicks dig it.

By the way I drive rear wheel drive vehicles, I don’t know if the preceeding correlates to front wheel drive cars. I suppose not.

Downshifting is about control and normal day to day stuff shouldn’t hurt your drivetrain. I will guarantee you every engineer who worked on the design of your car downshifts.

Many decades stick driver here.
I only use the brakes to come to a complete stop,usually when the vehicle is under ten MPH. There have been the foot to the floor squealers occasionally.Kid chasing the ball sort of thing.
I have never had to replace a clutch or even have it adjusted in either car or pickup,and it’s a point of pride to go the max with the pickups-16/18 Kmiles year,bumping 200K with current truck.
What’s hard on a clutch is the interface between engaged/disengaged.Pick one and don’t sit on the fence.

    Slight aside about pickup gearing.1st gear is the "granny gear" and seldom used unless heavily loaded at a standstill.

    Downshifting into 1st while moving is impossible with some gearboxes and dangerous with most.Sloping forehead,etc.

     I predict sticks will be a thing o' the past in a few years,even on trucks.

:dubious: Really? Given that there’s large international markets overwhelmingly dominated by manuals?

They may continue to manufacture them for overseas market, but I think they’ll disappear completely in the US. When I was shopping (end of 05) I was amazed at the lack of manuals available…not just on the lot, but absent from what is manufactured. If memory serves, for instance, Honda no longer offers a 5MT on the CRV, though they did a couple years ago. The new “option” will be CVT.

I engine brake a lot. I think as long as you shift smoothly and aren’t revving the engine too high, it doesn’t hurt a thing. I took a 90 Mustang GT to over 150,000 miles and my 98 Contour to over 180,000 miles, engine braking every day, never replaced the clutch on either one. Contour brakes lasted over 100,000 miles.

Say I’m going 55mph down a rural highway, engine RPMs about 2,500 in the Contour. When I know I need to make a turn, well in advance I take my foot off the gas, that starts slowing me down. Once my engine RPMs drop below 2,000 or so, I downshift to 4th or 3rd while matching RPMs, that puts the engine RPMs up to 3,000 or so, then when I take my foot off the gas I can easily slow down to 35mph or less without touching the brake. Sounds complicated but it’s not when you’re used to driving manual transmission every day.

I still do not get why people dont use the breaks its much much smoother and you have the added benefit have having your BRAKE LIGHTS come on adding to the saftey.

Don’t know, just don’t like braking. Gets my wheels dirty!