does shutting the engine off at lights wear out the starter faster?

[Eggman]

No, I think that was me. I've made that point before. I think it was here on MF.

Ha! I think I attributed the quote to Top Fuel due to that forum name used in the example.

1. When you're sitting and idling (stopped, with or without A/C), your car is getting WORSE mpg than a Top Fuel dragster on its run down the drag strip.

Click on the blue arrow box to go to the full original post.

I can't remember if it was you Eggman that I was going to quote, or describe. I think it was Eggman that pointed out that he hits his magic shut-off button as he is coasting, as soon as he can. Then he lets it coast down, and if it looks like he will come to a complete stop, just before he stops, he pops the clutch (out/in) in 3rd gear and starts the engine from vehicle momentum, and let's it idle while stopped, so he doesn't need to use the starter.

I've never considered shutting off the engine and bump starting it right before stopping before. At first I was like, whaaaaat? Then as I thought about it, I found that to be a very wise way to do use that technique, and prevent starter wear.

It's a fun game, as most hypermiling techniques are. I kinda miss them, and have tried some on my current vehicles including the Tesla.

I've had to push-start my old Dodge Colt station wagon (a Mitsubishi product) when the battery would run down, so I got pretty good at it early on in my driving career. It took a while to figure out why the alternator wasn't working when I put in the replacement engine.

I'm sure many here have push-started a manual transmission too. Same concept.

[Fummins]

The delivery cars I maintain are started dozens of times a day, they shut off at long train crossings, etc... The starters aren't super common to fail. If you use it more often, it'll wear out more. Just like anything. I wouldn't be too concerned about it. Starters are cheap(used) and easy to replace.

[Ares]

There is an Engineering Explained video that I'm too lazy to post (so google it) which experimented about auto-start-stop and confirmed that the average small 2.0L engine will start saving gasoline if the engine is off for 7 seconds. since the mirage has a smaller engine, I'm not sure if that raises the time to which one saves gasoline since it uses less fuel both during idle and startup.

Most traffic lights here in the Houston area have pedestrian crossing timers so I use best judgement to let auto-start-stop work or not.

The audi A3 that I rented had an awesome start-stop system that also works as soon as you let off the gas pedal allowing one to coast with the engine off. I found that, according to the MID calculations, coasting seems to yield the best fuel savings.

I do believe that auto-start-stop systems don't address fuel economy; instead they address carbon emissions. When the vehicle is off, there's no emissions. Hard to argue with that.

[7milesout]

There is an Engineering Explained video that I'm too lazy to post (so google it) which experimented about auto-start-stop and confirmed that the average small 2.0L engine will start saving gasoline if the engine is off for 7 seconds. since the mirage has a smaller engine, I'm not sure if that raises the time to which one saves gasoline since it uses less fuel both during idle and startup.

In my mind I'm trying to make sense out of that 7 seconds versus different engine sizes. A lot of variables. I will say though, when I start my Scamp cold (LA 360 V8), I probably use volumous amounts of fuel. It likes a very rich mixture when cold, and it likes raw fuel pump shots. However, when fully warmed, you could shut it off, say 30 seconds at a traffic light, and then just barely bump the starter and it will crank, and probably consume NO EXTRA gas in order to actually crank the car when warm like that. If it's warm, it cranks like it never shut off. Very quick, easy & efficient to start like that. So it would save gas the instant it is shut off when warm. Yet, I will not be shutting it off at a traffic light. I'm not wearing out THAT starter, and plus it just sounds BAD TO THE BONE. Headers, no cats, no resonators, no mufflers, wicked sounding at idle.

Plus, when warm, I've got it tuned to idle leaner than at a mixture in which it would idle better, more steady, etc. But it sounds like it's "got a cam in it" where I have it tuned. I shoot for ~13.5:1 at idle, but it would idle way mo' bettuh at 12.0 or 12.5:1. That engine has a personal love affair with gasoline.

I found that, according to the MID calculations, coasting seems to yield the best fuel savings.

Do you mean, kicking it out of gear and coasting with the engine idling? Or, I assume you mean coasting with the engine off? I'm not trying to pick on you, but when coasting, you're covering ground. If you use no fuel while covering ground versus using no fuel while sitting stopped ... OF COURSE coasting will yield the best fuel saving. Perhaps your meaning is a bit different than my mind is deciphering. I sort of have a one-track mind, so I might be misinterpreting.

I do believe that auto-start-stop systems don't address fuel economy; instead they address carbon emissions. When the vehicle is off, there's no emissions. Hard to argue with that.

When the engine is off while sitting stationary, there's no fuel being consumed AT 0 MPG, so IMO it is addressing fuel economy as well.

[Basic]

I can't remember if it was you Eggman that I was going to quote, or describe. I think it was Eggman that pointed out that he hits his magic shut-off button as he is coasting, as soon as he can. Then he lets it coast down, and if it looks like he will come to a complete stop, just before he stops, he pops the clutch (out/in) in 3rd gear and starts the engine from vehicle momentum, and let's it idle while stopped, so he doesn't need to use the starter.

No, it was Loren. It works stupendously.

[Ares]

Do you mean, kicking it out of gear and coasting with the engine idling? Or, I assume you mean coasting with the engine off? I'm not trying to pick on you, but when coasting, you're covering ground. If you use no fuel while covering ground versus using no fuel while sitting stopped ... OF COURSE coasting will yield the best fuel saving. Perhaps your meaning is a bit different than my mind is deciphering. I sort of have a one-track mind, so I might be misinterpreting.

See below.

The audi A3 that I rented had an awesome start-stop system that also works as soon as you let off the gas pedal allowing one to coast with the engine off.

I believe the A3 has a 7sp dual-cluch auto so I'm not sure if the system disconnects the transmission when coasting. The restarts from engine-off during coasting is so smooth that I can't imagine the system is 'bump-starting' the car, but I may be mistaken.

When the engine is off while sitting stationary, there's no fuel being consumed AT 0 MPG, so IMO it is addressing fuel economy as well.

Not if the engine consumes more fuel restarting, a.k.a. engine did not stay off long enough. I would say bump-starting a car from a stoplight is not something the average person can do; at least not in my neck of the woods.

[Ares]

https://www.tomorrowstechnician.com/...start-systems/

You may think that the most important enabler would be the starter motor. But the only difference you might see between an Audi stop/start starter and a conventional one might be the gear. The reason why the system is able to restart the engine quickly is the assist it gets from the direct injection system working together with the ignition system. When the engine stops, some of the cylinders are positioned with the piston traveling downward on the power stroke. When the driver lifts her foot from the brake pedal, a small amount of fuel is injected and ignited, which pushes the piston down and turns the crank.

That may be the reason why starting is so seamless; seems like a fraction of a second to start compared to the honda auto-start-stop system that seems like a 'normal' starter 'turning' the engine.

Below is the EE video on start/stop.

[Fummins]

https://www.tomorrowstechnician.com/...start-systems/



That may be the reason why starting is so seamless; seems like a fraction of a second to start compared to the honda auto-start-stop system that seems like a 'normal' starter 'turning' the engine.

That's interesting. I know someone with a newer Grand Cherokee (v6) that has the auto start/stop feature. While lots of people would be thrilled to have the option to be able to disable the system, this guy was mad that it quit working once it was about 9 months after buying it new. Turned out one of the two batteries wasn't 100% up to snuff so the car would constantly say something like "conditions not met" or "car not ready" for the feature to work. After 6 or so dealer visits and replacing the wrong battery, they finally figured it out...

[7milesout]

I forget what these style starters are called, but they have them on scooters. The Honda PCX uses this certain kind of starter. There's a video how it works. From memory, the engine is somehow positioned so the starter can get a "running start" turning before it hits the compression stroke. And seems there's more to it than just that.

But I rode a PCX. And from OFF, to started, it's sort as if the engine just starts making noise. The starting process is very smooth, quick and quiet. This starting system uses less battery power and is super smooth. It may have been adopted to make this start / stop on scooters not wear out batteries and starters since all that stuff is so small. I'll have to go back and read about it again.

[Ares]

There seems to be A TON of parameters to ensure auto-start-stop works.

In my (almost) month with the A3, I thought I broke something when the auto-start-stop system stopped working. I then realized the rear HVAC dial was on the hot side which prevented the system from engaging.

In other start/stop horror stories, apparently some Pilot and Passport models would engine stop and would not restart. It took Honda several years to finally admit it and release a fix. Fortunately, I have not encountered it on my Passport before I got the fix performed.

It seems there are more people who dislike auto-start-stop technologies, though. I don't have any problem with it with the exception of during the summer when every second of AC is needed.