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Old 09-30-2009, 05:27 PM   #54 (permalink)
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Quote:
Originally Posted by Jammer View Post
I should phrase my thoughts better. I had thought I had said pretty much the same thing as the last two of you did.

Thanks for replying though.

Wait: Old Mechanic- Are you saying that you go down hill in low gears with the ENGINE TURNED OFF SO NO GAS IS USED? I don't think I have tried that yet because I keep thinking the engine would restart, but if my key is turned to OFF, I guess the engine wont start, eh? Oh well I was doing almost the same thing but I had the engine ON, and this lead to fairly high RPMs as the low gears slowed me down.

Sorry if I misunderstood.
If you are using the engine to slow the car down going down a steep slope. you are using no fuel with the ignition on due to DFCO as Pale stated.

Example:

You crest the hill (top) and start down. The hill is very steep so you downshift with your foot off the gas. No need to turn the engine off. It's not using any fuel anyway. Steering and brakes work normally.

If you can not slow down enough using the gears and your are worried about the engine revs getting too high, apply the brakes momentarily to kill some speed, but keep the car in gear with your foot off the gas pedal. You are getting infinite mileage when your foot is off the gas and the slope is keeping your revs up in any gear.

As you approach the bottom of the hill you have two choices. If you have enough time use EOC (engine off coasting). If you don't have enough time, put it in neutral and let your speed increase some (Maybe 10 MPH). You want to use the speed to get you as far up the next up slope as possible without danger or a ticket.

Its a lot like a roller coaster, but you have to be safe with your maximum speed.

If the speed limit is 50 MPH, your highest speed would be at the bottom of the hill, and your lowest speed would be right before you reached the crest of the hill. This is just like a roller coaster. I use the roller coaster as an example because it can go very far without any power at all, after its first climb under power.

regards
Mech
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