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This is a discussion on Is it safe to coast in Neutral? within the 4 speed Automatic (4T65E) (4T65E-HD) forums, part of the W Body Tech category; Not sure exactly which tranny I have...had the car for two months now. But I was curious if it ...
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| | #1 |
| SE Level Member | Not sure exactly which tranny I have...had the car for two months now. But I was curious if it is safe for the car to coast in neutral when I don't need power to save gas? I've hear it heats up the tranny, I've heard it's fine, but thought I should ask someone who might actually have a good idea. It's an 02 four door GTP.
__________________ 2002 3.8 series II GTP U bend and resonator delete |
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| | #2 |
| SE Level Member | I don't know if it's safe or not, but how would it save gas? With it in gear, you'd be using some of the energy from your forward motion to keep the engine turning instead of having to use fuel if you put it in neutral. BTW, you have a 4T65E-HD.
__________________ 2001 Buick Regal LS - Almost Stock |
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| | #3 |
| SE Level Member | what you said kinda makes sense, but all i know is the rpm's drop a lot, my fuel mileage shoot's up, and with this car and my last mustang, it saved me gas. And thanks for the tranny info!
__________________ 2002 3.8 series II GTP U bend and resonator delete |
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| | #4 |
| Approved Vendor | it supposedly saves gas by lowering the rpm's while going downhill, the momentum, and gravity move the car. It is illegal as far as I know
__________________ Steve '97 GTP VS cam, ZZP PCM, and not much else yet |
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| | #7 | |
| Administrator | Quote:
Its illegal here as well, but I did it anyway. But there are only about two good spots in which I can coast for any length of time on my daily drive to and from work but it amounts to about a mile and a half total. I go over quite a few hills on my way to work but unfortunately none of them are steep enough in the decline to keep momentum going. But since they are successive hills, when Im on the decline I'll give it just a small amount of pedal, just enough take advantage of the momentum and then let out of it a bit more aggressively when I go up the next hill. Use a little gas to go a bit faster down, save a lot of gas going up by now having to power as much. There is not one big thing you are going to do to increase fuel economy. Its going to be several little things that are going to add up to big gains in the bigger picture. My GP got 27.5 - 28.0 on all highway runs. I was getting 33 shortly before the tranny went due to the differential. I had hit 34 before but 33 was more common. And it has not been tuned either. My '95 Rodeo barely and I mean BARELY got 17mpg when I bought it a few months ago. It is now getting around 23 mpg combined driving. I would imagine all highway I could probably push 25 out of it. So think little steps. Sometimes you can get a couple mpgs from one thing but dont fret if you dont. I keep meticulous fuel records and track my fuel economy like scrooge tracks money. There is no point at all in trying to improve fuel economy if you dont do at least the basic thing of tracking your fuel economy with some kind of written record.
__________________ Scotty Hall Bartlesville, OK 2001 Pontiac Grand Prix GTP It whines a lot, but I like it. Even if you shoot for the moon and miss, you still land among the stars. | |
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| | #8 |
| Community Vendor | I don't do it to save gas...if I am in neutral, and coasting, that means I am approaching a red light that I know is going to be a rather long one. Other than that, I leave it in gear 4th on the highway, and I will shift it down into 3rd while in the city. ~F~
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| | #9 |
| Community Vendor | Somewhere I read that it could actually cause damage to the transmission. I think because the pump isn't moving as much fluid, and the trans is still turning quite a bit internally. I imagine Dave could say for sure though.
__________________ GreenBastardPerformance 2000 GTP Coupe (the green bastard) XP, Pacesetters, LS1 TB & MAF,MSD System, P&P LIM, P&P GenV w/ 3.2, 3.0, 2.8, Devil'sOwn Injected 100% Methanol,PowerTuned, TripleEdge Trans w/3.29's 12.97 @ 106mph |
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| | #10 |
| Approved Vendor | I know if the car is off it's bad for it, maybe that's where it came from. I'm not sure
__________________ Steve '97 GTP VS cam, ZZP PCM, and not much else yet |
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