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Old 07-22-2009, 12:51 PM
  #11  
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Originally Posted by DreamHHR
The engine keeps turning and it's not any different than normal behavior on deceleration; in fact I couldn't tell if I was not seeing the scanguage reading.

What's the harm? The engine is still getting lubrication, and it's the transmission that is turning the engine, but other than a bit of an extra load on the transmission, I don't see what could go wrong.

Yves
it probably does no harm.....but i see it like people using a manual trans to slow down instead of brakes......brakes are cheaper and easier to fix than trannies....and gas is not free.....i will consider that it may even be benificial to the rings and cylinder walls since there is no pressure pushing the piston it may be cleaning those parts , but i doubt it.....have you ever tryed to turn an engine by hand ?....either way i would surely think that less rpms on the engine means less fricton and wear....so my next ? would be about rpms and cooling.....less the rpms = less the cooling needed , unless the engine is stopped completely and no coolant would then be circulating....so now me think -coasting good if engine is still turning low rpms , and reverse lockout is working
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Old 07-23-2009, 11:28 AM
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[QUOTE=catdaddy137;399184....so , what about the 2 other gears ? will go down past D without the lever thingy?....is this info in my owners manual ?...i've heard of a few having issues with the auto shifter , so i've always tryed to be gentle but firm with mine....i really can't believe i put it in R , but i did....i get a little tired/stressed on my 275 mile a day route.[/QUOTE]

No it won't go past D. It should only bump between N & D without touching the button (lever thingy). I don't think its in the manual.
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Old 07-23-2009, 11:36 AM
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Originally Posted by twistrman
...would want to know what the I is for more before i did it.

in D i definitely think there is a mechanical drag. As soon as i switch over the mpg shoots up. Even if it didn't though, with Less resistance I can roll a lot farther. I have to watch the speed on mine since it is technically 25 or 35 (who knows...)
The I is for Intermediate. Kinda like the old 2 on the shifter. I changes the shift points. IIRC they go to 3500 RPM from 2500 RPM and you lose the OD. Definitely higher performance in I.

The MPG does get better if you coast. Even though there is now fuel going to the engine as opposed to the cutoff on decel, you are not linked to the drivetrain and the car will roll farther in neutral than it will in D. I know I get better mileage when I do it.
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Old 08-05-2009, 03:18 PM
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I have a 5 speed manual transmission. today at speeds of about 30-45 I shifted into to 5th going down hills or on long straights on level ground. My mileage average went up .5 mpg in 20 miles with 250 total miles on the average. So I think if it went up that much in that short of time that it was really helping the mileage. I will continue this test and reset the meter and we'll see how it goes. JC
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Old 08-06-2009, 05:34 AM
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Just to let you know in most states it is illegial to coast in neutral.

Something to do with being in control of your vehicle...
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Old 08-06-2009, 09:29 AM
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Originally Posted by solman98
Just to let you know in most states it is illegial to coast in neutral.

Something to do with being in control of your vehicle...
how would any officer know you are coasting in neutral?
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Old 08-06-2009, 09:37 AM
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Originally Posted by twistrman
how would any officer know you are coasting in neutral?
That, I can't tell you.......... But I guess if you got in an accident, it may come up.
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Old 08-06-2009, 10:06 AM
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Roller Coaster (of love)

I used to coast all the time with my old shifter (Nissan 5-speed). No coasting now with my Auto trans HHR. An automatic tranny seems to coast more anyway (in gear or not).
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Old 08-06-2009, 11:12 AM
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Originally Posted by solman98
Just to let you know in most states it is illegial to coast in neutral.

Something to do with being in control of your vehicle...
If you are actively shifting from D to N and back again, aren't you controlling the vehicle - even when it is in neutral?
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Old 08-06-2009, 11:40 AM
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Originally Posted by solman98
Just to let you know in most states it is illegial to coast in neutral.

Something to do with being in control of your vehicle...
I think it's allowed in coastal states on coastal highways.
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