Engine off coasting?

[cbaber]

My opinion is that bump starting is the best thing to do. Whether you are using the starter or bump starting the process does the same thing. Spins the engine with the ignition on until it fires up. The difference is whether you wear on the starter or the clutch. When bump starting I always use the highest gear possible in order to minimize the "lunge" which makes it easier on the clutch. Of course with using the starter you avoid the lunge if you rev match.

The reason I chose bump starting is because its a simpler process. Let off gas, clutch in, turn key back, wait a second, key on. Coast. When my speed gets down simply let off the clutch and I am back driving. With starting its the same except when you need to start again you need to turn the key. Its just an extra step.

I suggest doing it whatever way is more natural. The key is to get a rhythm that is smooth and effective so you can do it over and over to maximize your coasting time and MPG.

[GRU]

It would be interesting to see long term results with 2 identical engines driven the same way but one being shut down more frequenlty. Although it would be pretty much imposible to do an identical test. It's pretty much guaranteed that an engine that's shut down all the time will have more issues, if not with engine internals, but for sure the belts, clutch plates, etc.

[Sven7]

Has anyone had issues with the fuel pump or other devices that turn on and off with the engine? I've got a lot of friends telling me I'm killing the Probe.

[Georgboy]

I have not had any issues with my car yet... Every car is different though, just like every tank of gas lol.

[shockj2000]

I just bought a 92 civic hatch its bone stock. I got 41.3 mpg my first tank and second tank was 46.2 mpg.. I did a few mods and cant wait to see if i gained a little but I tried the engine of coasting a few times today. Normally its at 60 plus mph so i pop the clutch in 5th gear once it looses too much momentum. But it does worry me as well that maybe it will be more costly for clutch repairs and so on by doing this compared to the gas savings. And by popping the clutch i mean just bumping it over instead of using the starter not actually "popping it". My question is for those that have been doing alot of engine off coasting. How long have you been doing it and if u noticed anything out of the ordinary from doing it..

[moorecomp]

3+ years, 80,000+ miles of using EOC. I average over 10% of my miles per tank as EOC miles, and have no issues so far with my clutch. I would guess I bump start about 10-20 times per days commute (not so much if at all in the winter though). One of these days I will make a video of my bump start technique.

[Fat Charlie]

Originally Posted by SentraSE-R

The automotive pundits say 7 seconds is the magic number with modern fuel-injected cars... You'll use less gas to restart it than you'd waste idling.

Originally Posted by SentraSE-R

The 7 second comparison is strictly fuel used. It doesn't consider electricity to crank the starter. Bump starting is more efficient than using the starter, but you may pay by replacing your clutch sooner.

Unless it considers the fuel cost of the cranking electricity then it's not a comparison at all.

The wear and tear issue of frequent cold starts doesn't really come into play with EOC because the engine doesn't cool down much. In the winter I shut off the blower fan to keep the coolant temp up, but none of my EOCs are long enough to drop the temps below the operating range even if I had the heat blasting.

I don't consider the wear on the clutch at all because you either excessively wear it or you don't. A good bump start is easier on the clutch than even the best standing start- you're using the clutch to move a few pounds of well lubricated engine innards just enough for the ECM to throw a spark at them. From a stop, you're using the clutch to move a whole car with a bunch of rolling and environmental resistance. If you can do that well, then the clutch will never notice that you now bump start. If you can't bump start well, then it's probably your regular driving that's killing the clutch and the bump starting is going to get the blame because you started doing it at around the same time you started paying attention. At that point your efficiency/value question should be whether you're better off with your own sloppy clutch work or an automatic's sloppy clutch work. You probably are- swapping a clutch costs a lot less than overhauling an automatic.

[shockj2000]

Originally Posted by moorecomp

3+ years, 80,000+ miles of using EOC. I average over 10% of my miles per tank as EOC miles, and have no issues so far with my clutch. I would guess I bump start about 10-20 times per days commute (not so much if at all in the winter though). One of these days I will make a video of my bump start technique.

what would be your reasons for not using it in the winter time

[moorecomp]

We get a lot of snow and ice here and it is not worth the possible loss of control by sliding tires trying to do a bump start.

[bestclimb]

I don't do it in the winter time because I own a car for convenience, I find heat to be convenient. That and the slush on the roads makes the coasts pretty short.