Does down shifting put extra wear on the engine and interlaced components?

Surely it makes your brakes last longer, but is the cost on your engine worth it?

http://tinyurl.com/22ors5

Hm, but if your only concern was making your car last longer is it a wise choice?

Lets say you used it to stop at stoplights. Is that more strain then you should really be putting on your engine?

Right, this is what I usually do. I had an argument with a friend recently where he said he didn't do this because it puts a big strain on the engine. Thats what I want to explore.

I have enormous feet. Any attempt at fancy triple pedal work will result in my feet jamming under the pedals and bad consequences.

What mr. Dettmer referes to here is called engine braking. It means using the engine's compression stroke instead of the brakes to lower the vehicle's velocity. Works only with manual or sequential transmission and 4-stroke or diesel engine.

A few points:

1. Using a modern synchronised (i.e. post-50's) gearbox you don't have to manually match shaft speeds in the box, though greater speed differences cause slightly more wear on the synchromeshes (devices inside the gearbox that perform the synchonising for each gear). Those generally have a life span of 400 000 km and more so...::) It's not possible to even try to engage a gear if the speeds are far too mistmatched, it will simply not engage if your synchromeshes are ok. If you really really need to, you can use double clutching.

2. Double clutching is a way to match the shaft speeds in the box. It's tricky to learn how to do and when to do and it's only useful rarely. An example would be under extremely slippery conditions when it would be safer to force in a much lower gear than is generally sane and use engine braking instead of brakes in order to prevent loss of control (ABS tends to prevent you from actually braking under extremely slippery conditions). It's a last measure way to slow down the vehicle before a stop when you notice you'll overshoot with regular braking but it needs to be done early enough to actually manage to slow down enough.

3. Heel and toe is a racing technique. Pointless in street driving and your gearbox will not take kindly to your practising. It's most useful with sequential racing gearboxes that are usually made to sustain much more abuse than regular manual boxes can handle.

4. Engine braking saves fuel on fuel injected and diesel vehicles because when the injection ECU (elecronic control unit) notices the driver wants to engine brake it'll lower the fuel supply amounts to very minimal, or even fully cut off. It's a fuel saving technique first and a braking techique second. In fact, if you do engine braking all the time like I do you'll end up with glazed, squealing brake pads like I did. Brakes need to be roughed up periodically to be in good working order.

Engine braking however doesn't give your gearbox, clutch or engine any trouble they weren't made to handle. Except if you've double clutched into first from a higher speed, then you need to slip the clutch quite a lot.

I usually come to an intersection rolling at 4th gear near idle speed, then shift down to third, as i gently release the clutch, the rpm rises to something like 2k. Then i shift to second and release the clutch (rpm rises much higher this time), and as the rpm drops I prepare to press on the brakes. When the engine coming to near idle rpm's I press the clutch and maybe brake a little and when i'm real close to my intended stopping line I press much harder on the brakes.

If someone can find a program that converts nokia .3gp videos to more sensible format i can record a video demonstration.

Matching RPM's to eliminate shock when the clutch is engaged (regardless of double clutching, I mean at time of releasing clutch pedal) will help stuff last longer. Sudden RPM changes are especially hard on timing belts.

A bad habit I see a lot of people do is to constantly rest their hand on the floor shifter, which wears out the stuff that actually slides the gears around.

And I'd venture to say that a modern engine in good shape with regular (quality) oil and filter changes won't suffer from 2000 rpm, or even 1600 rpm while cruising.

OTOH, brakes are cheaper to overhaul than engines, the problem with excessive braking would be heat buildup in the calipers and disk, the disk could warp, causing pulsating pedal and "locking" the wheels at the high spots (while overall braking effect is still low), the piston(s) in the calipers could build up varnish (from the overheated brake fluid) causing them to stick (applying the brakes all the time) and the fluid itself would deteriorate. Get your brake fluid changed/flushed every couple years, helps even to get rid of accumulated water. If you were VERY extreme, the fluid could boil, causing very mushy or no brakes at all because vapor compresses quite easily.

[EDIT]
Years ago I drove a cab for a congenitally cheap owner, I told him the brakes were "chirping" (a little warning tab that squeals before the brakes are totally gone) two weeks before the actual rivets scored the rotors, I downshifted the automatic to make them last longer before it wore the rotors down to the cooling vanes.

Well, our van's diesel engine made it 400k miles before it needed an overhaul.. Which is pretty good. Diesels are generally built heavier, I think.. So if you were looking for something to run a long time, that's what I'd go for.

Did I forget to mention I'm driving vehicles that are 21+ years old?

I guess maybe it depends on the vehicle, but our automatics engine brake when you let off the pedal(unless they're not working properly).

And saying automatics are for sissies isn't ENTIRELY true... I mean, you're going to spend more time working on them and getting headaches...

edit:

I'd be surprised if they did. My former Peugeot 205 GTi had 3000 rpm on the dial when "cruising" at 100km/h.

2-strokes don't have much of an engine brake characteristics. They do some, but not in any usable degree in road going applications. God knows i've driven my fair share of mopeds and 125cc two-stroke street bikes and none of them had any usable engine brake power. Dirtbikes can do it because the drive ratios are much tighter.

They do some, but they have this nasty habit of constantly applying some torque. Heavy diesels with automatics might have more aggressive lockup mechanics in the torque converter, that's why they do engine brake better.

The attached .mp4 video displays the engine braking. I pulled from an offramp and simply didn't touch the accelerator, only shifting to smaller gears until almost near idle at second when i did tap a bit on the throttle when shifting to first to make the transition from rolling back to engine braking a bit smoother. The car is a 1989 Peugeot 405 1.9 SRi (XU9J2 engine with Bosch L3.1 Jetronic injection and BE3 gearbox).

(you can barely hear the engine, the studded tires make an awful noise).

Hey, that's a little harsh don't you think? I had a toyota pick up truck with about 160,000 miles (250k km?) and the timing chain broke on it, trashed the head and bent some valves. Costed me $600 to get it fixed and back then (when I was poor) it took me 3 months to save up the money...

me too toyota celica 1990. mines has way more miles on it though. i wish i was in my home contry with it. i wouls spray it and fix every thing on it. its a good car. very fast and powerful.
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A lot of you sound like you are much more experienced than me so my opinion is probably uneducated and novice.

It seems like brakes are made for braking and if you're not hard on them they won't disintegrate. You shouldn't need to 'heel toe' or double-clutch to preserve your brakes. As I think somebody said, engine and transmission repairs are more expensive than brakes.

I used to watch the automotive TV shows on the weekend (we used to get them, most of which were about high performance muscle/sports cars) and I remember them saying that in terms of racing it is beneficial to use these techniques: speed equals win. Serious racers do constant repairs anyway because their cars are meant to go fast; the cars are only preserved if the owner can't afford to race hard.

I would say most people wouldn't use these techniques correctly and would likely cause more harm than good. Experts recommend you practice because it does require learning the car and/or learning to actually heal-toe or double-clutch, which usually requires the pedals to be closer together as well as some flexability and coordination. Also, a Honda won't be designed for it from the factory and you will probably slip off the brake and wreck trying to do it. In other words, if you're not speeding in second gear your car is likely not configured for it and might need customization to do it correctly (the pedal mechanics, not the drivetrain).

That doesn't speak for those of you who know what you're doing (assuming you do), but for those that are cheap and see this as a way to save money I'd recommend you stop trying to cheat the economy.

Personally, I have a heavy foot, but even so I always prepare to stop early and usually coast towards traffic lights (an object in motion... stuff). I never have to put much pressure on the brakes because of this. The majority of drivers come into a traffic light at cruising speed and stop hard. I don't understand the point of putting extra stress on brakes (or drivetrain, in your cases) when you know you're gonna have to stop.

I don't live in a large city so I can't say how I would drive in extremely busy streets. The population where I live is around 80,000 - 100,000.

In terms of downshifting and revving the engine to match the RPMs this has always seemed a natural thing to do. Unfortunately I haven't had much experience with a manual transmission so I can't say that I've had a lot of experience with it. The few times that I did drive a manual transmission I would just disengage the clutch, move the shifter into neutral, and brake smoothly to a stop. When completely stopped I would shift to first in preparation for take-off (with the clutch still disengaged).

When I have the money I will buy my own car (I still drive a 3rd of my parents since I'm only 20 and in college) and I'm planning on getting a manual transmission. I'd like to look into the new Dodge Challengers (Hemi'd, of course), so we will see how long it takes me to afford one...

No offense, but European cars suck. It's all about American muscle and Japanese tuners. How many have seen Chrysler's super car concept, the ME 4-12? It was planned for production, but I'm not sure on the status - I think it was cancelled, but forget why...

I'd still love one. The name comes from the Mid-Engine 4-turbo charger fed 12-cylinder engine. Apparently it was breaking records before production and was supposed to be a strong competitor for the Italian super cars. Especially considering the Chrysler ME 4-12 was estimated to cost only $125,000 USD (as I remember).

I'm also a huge fan of Dodge Viper, although I probably prefer the rounded nose of the late 90s to the newer models. Dodge, why did you change the Viper!? Change it back!

One thing they didn't break is the Dodge Viper Competition Coupe, which had a concept sibling street version that was actually pretty much identical, inside and out.