Slowing down in neutral vs in gear

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I can't say what the BMW uses, but it wouldn't shock me if it were just that.




No, even back in the early 80s the economy meter actually used the current fuel flow rate from the ECU(not vaccuum).
 
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Well guys, I guess we'll just agree to disagree. It's a matter of driving style. But I can tell you this...I've always used down shifting techniques. Does it contribute to additional clutch and transmission wear? I dunno because on at least 3 vehicles that I've owned in the past they went over 100K miles on the original clutch and sold them with the factory clutch intact. And one vehicle (1983 Mazda pickup) had the ORIGINAL brake pads when it blew a headgasket at 106K miles.




Well I certainly have no grounds to say that I'm better with a standard or easier on the car than you, and it's not like I never downshift when coasting. I learned to drive standard on my Mazda3, which only has 30K miles now, and I've only put 12K miles on my Pathfinder since I bought it. There are many situations where it makes sense to me to use downshifting to vary speed, but more often it seems better to me to just leave it in a higher gear until I need a lower gear. I just remember back when I first started; I'd usually put it in neutral when coasting, and just jam it into gear when I needed to without rev-matching, relying on my synchros. Since most of my driving is highway and I was living in a city of 11,000, it probably took me 2 years to reach the point that I believe I could drive a standard around a track faster than an automatic, and that my transmission is going to out-live any automatic. The subject of coasting in neutral just reminded me how much I'd like to go back a few of years and teach myself how to drive. I basically bought a standard and drove it until I knew how to. A lot of the things I felt I did wrong when I was first learning are things that I see many still do after years of driving. Downshifting wasn't one of those things though.
 
When I'm slowing down for something like a stop light I try to be as smooth as possible and as the speed drops I shift to the next lower gear to keep the engine going at speed that matches the road spead in that gear. There is a slight bit of drag supplied by the engine but not much at all. Since I'm matching the engine speed to the road spead I make the down shifts without the clutch. It's just not needed. But none of this works if you're in a hurry or the light is a surprise or there are people pushing you to be first to the red light. I get beaten to the light all the time. I'm so poor at hitting the red lights that often, it has just turned green as I arrive. I have to suffer the shame of missing another red light and just keep moving.
 
As far as active downshifting is concerned, I understood a number of years ago that this is fine for racing, where wear & tear is not an important issue, but for longevity of clutch / transmission it's better to avoid it.

My practice is similar to some other responders to this thread. When slowing down with our MT Dodge Dakota, I try to anticipate as far away from the slow down / stop as I can, getting off the gas and leaving the transmission in the gear selected. When the front brake pads were replaced recently for a locked right caliper, the mechanic remarked that the left pads looked "new" (on a 45K vehicle).

As far as our AT car, the SAAB has an Aisin (owned by Toyota, I understand) 5-speed, and it downshifts itself when you get off the gas and slow down; you can feel the engine braking, too.
 
I've got somewhere around 200k on the current clutch and brakes. I use the downshifting to keep the engine engaged and not to help much on the slow down. It's just a little 4-cylinder and I think that this practice allows the engine to use the whole car as a flywheel to smooth it out. I make driving carefully a habit because speeding just gets you tickets and wears the car out. Acutally you can make driving very smooth a game. It gives you something better to do than talking on the phone. It may sound stupid, but It's something I can't help. I try to get all the way to work without ever having to use the brake pedal and still keep out of the way of others. The brake pedal is the most expensive pedal in the car.
 
Put me in the camp that leaves it in 5th gear to help slow the car...I don't row it as I slow. I'm experienced enough to know which gear to select based upon my speed at the moment in case I don't have to actually stop.

Nothing is free when you talk of using throw-out bearings/fork, and clutch face material when compared to brake pads. IMO, brake pads are much cheaper than rowing down through the gears to stop. Your passengers will thank you also.

Re: downshifting an auto to slow quickly on slippery surfaces...of course you must consider what speed you are going when you select the gear, as well as the surface you are on....sure it can spin you out if you don't do it right. That's why I said one must practice in a parking lot/etc., first.
 
Clutch wear is minimal if speed matching is done correctly. I hate when people downshift and just let the clutch out, at least blip the throttle a bit! I've had cars in which I used the clutch very little once moving. I've never replaced a clutch or transmission on one of my cars and I've taken several to 200k.

In most gassers I tend to just coast in the gear I was in when I started decelerating, but in my Jetta turbo-diesel if I think I'll need power before stopping I tend to row to keep the turbo spooled. With 60 HP it needs it!

Three pedal technique is a must IMHO for proper spirited manual trans driving, i.e. matching speeds while downshifting and braking.
 
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