EOC on the highway, some questions
 

I've been getting a little bolder about EOC, i recently started doing it on a couple good spots on the highway. What I normally do is get up to 60 (keeping my instant MPG >35-40), turn the engine off, coast (in neutral) down to about 52, and bump start into 5th gear

1) is this hurting my car? is there a better way to do it? should I not be doing EOC at those higher speeds?

2) I just read another thread about messing up an engine if doing EOC by shutting off the engine.....is this an issue with newer cars (ergo, my '09 cobalt?) I gathered that I should be letting the engine drop to idle before turning off the engine...is that enough?

listen.. i;m not the expert, but i just wouldn;t do it. there;s been a couple people that commendably wrote-in to say they regret it. -- it cost them their transmission.

i was doing engine on coasting in nuetral in my old accord since late september.
i got a new timing belt in september. my new belt is starting to squeal since december.

it;s very rare i engine on coast, now.

This is only an issue for carbureted engines. For fuel injected engines, there is no risk of sucking extra gas into the combustion chamber when you kill the injectors.

I recommend a kill switch instead of cycling the ignition, mostly because all your computers - airbag, ABS, ECU, etc. power down when you turn the key.

Personally, I don't feel that P&G pays at high speeds, unless I'm headed downhill, but that's your call to make.

I P&G all the time. Thats one of the major reasons I get 200%+ EPA rating in summer. I've been doing it for over 20k miles, no adverse effects so far. Most of the miles I travel are highway.

15k with lots of EOC with my Honda... but then, if I break it, I own it... :)

I need to address this, because I feel that it could be misleading to anyone who doesn't know any better.

Your timing belt is not affected by whether or not you are coasting with the engine off, on, or otherwise. Your timing belt also does not squeal. Squealing is a sign of belt slippage. If your timing belt were slipping, your engine wouldn't be running. Period. Full Stop.

Also - You won't lose a transmission using EOC in a manual. They're designed to be splash lubricated, and some part of the transmission is always churning fluid when the vehicle is moving. In case nobody noticed, he "bump starts in 5th gear." That means he's got a clutch.

I also recommend a kill switch. If you're bump starting correctly, it won't cost you a cent in clutch repairs, because the clutch will still last the 5 years it's supposed to. If you're screwing it up, prepare for a repair bill. There is mention on this site in several threads about the proper shifting technique and clutch starting for manual transmissions. If you're unsure about how you're currently doing it, I suggest you read up and avoid a head ache.

Those things said, EOC will help any time that you have more space than you would travel by just letting off the gas. Pulse and Glide (what you're describing) usually won't work at higher speeds, because aerodynamics tends to eat a big chunk of your engine's output just trying to accelerate. If you're noticing higher numbers on your eco-meter, chances are, it's working for you, but not everyone will see those same results. [I know I freakin' didn't... :'( ].

By the way, in case nobody said it yet, as always, no matter what the situation, YMMV - Your Mileage May Vary.

Nobody's going to have the same experience you have, so your best bet is to do some research, form an opinion, then test it yourself. Nobody will be offended if you don't just take their word for it here. We're all adults. Most of the time. :)

Same here. 175,000 total miles, 30,000 with P&G, and not a hint of clutch or transmission trouble.

Burnt -

I've been doing strategic EOC for about 75K miles. No known problems.

CarloSW2

"Oh crap! There's a good spot! [panicked engine shut down..... bump start] Whew - good strategy, team!"

At least that's what I used to do. LOL.

Been doing EOC for years. Late last summer I had my engine and transmission (with original clutch) replaced. The transmission had 512,000 miles on it, of which over 200,000 miles had been with EOC on every downhill and when coasting to stops. The clutch still had about 1/4 of its lining left on it.