Automatics changing my view.

[GasSavers_RoadWarrior]

Park actually lowers the lube pressure or stops running the pump on some vehicles (Chrysler transmissions do it) so idling in Park should take less gas than idling in neutral. Might only notice this with a small motor though, hemi truck it might not make a difference.

[add|ct]

Originally Posted by 101mpg

That's the thing - it's not actually unloaded entirely! The Malibu Maxx & the Grand Caravan actually stay "in gear" when in neutral - keeps the fluid spinning to cool it I guess. And there is an audible as well as you can feel the vehicle slip out of gear once you get below 5 MPH if you coast to a stop!

Plus you can view it on the MPG readout as well - but it does not entirely go into neutral.

I have this problem with my Stratus. If I shift into neutral the RPMs don't drop into its true idle until nearly stopped(5 MPH and breaking). Finally, the engine goes into an idle of 750rpms and it virtually stops itself on any kind of incline. Before that, the RPMs tend to hang anywhere from 1200-1500rpms prior to coming to a halt.

Originally Posted by RoadWarrior

Park actually lowers the lube pressure or stops running the pump on some vehicles (Chrysler transmissions do it) so idling in Park should take less gas than idling in neutral. Might only notice this with a small motor though, hemi truck it might not make a difference.

I agree. I get similar response from my Dodge Stratus '99 2.4L. I have more success with a smoother idle while in park than in neutral. It takes longer to get to a resting idle, especially when the car isn't warm or is only doing short trips.

I was wondering if I could change over to a better A/T fluid at the next fluid/filter change, though. A mechanic I used to use just did a swap for me around 25k ago and the torque converter feels like it takes a moment to really engage. I get a real dip in RPMs while in electronic O/D(it is a 4 speed), as soon as I hit the last gear doing about 45MPH+ while still accelerating. Its somewhat of a delayed response to get the power I'm asking for, throttle wise. That finally gear is tricky. I

I'd imagine a better A/T fluid at my next change could help some, but perhaps at 122k it could still improve with regular service intervals. 2 owner car. My sister had it from about 25-30k onward after it was a dealer owner vehicle at first. The dealer put over 20k into it in less than a 18 months according to CarFax reports. I purchased it at around 89k miles from one of my sisters. I was in need of a car at the time and couldn't be picky. I wouldn't have paid as much in hindsight.

I can still squeeze 26/27 MPG out on the freeway, but that's doing 70MPH. Perhaps closer to 30 at 55-60 MPH.

[SarkOzy]

Originally Posted by add|ct

I have this problem with my Stratus. If I shift into neutral the RPMs don't drop into its true idle until nearly stopped(5 MPH and breaking). Finally, the engine goes into an idle of 750rpms and it virtually stops itself on any kind of incline. Before that, the RPMs tend to hang anywhere from 1200-1500rpms prior to coming to a halt.



I agree. I get similar response from my Dodge Stratus '99 2.4L. I have more success with a smoother idle while in park than in neutral. It takes longer to get to a resting idle, especially when the car isn't warm or is only doing short trips.

I was wondering if I could change over to a better A/T fluid at the next fluid/filter change, though. A mechanic I used to use just did a swap for me around 25k ago and the torque converter feels like it takes a moment to really engage. I get a real dip in RPMs while in electronic O/D(it is a 4 speed), as soon as I hit the last gear doing about 45MPH+ while still accelerating. Its somewhat of a delayed response to get the power I'm asking for, throttle wise. That finally gear is tricky. I

I'd imagine a better A/T fluid at my next change could help some, but perhaps at 122k it could still improve with regular service intervals. 2 owner car. My sister had it from about 25-30k onward after it was a dealer owner vehicle at first. The dealer put over 20k into it in less than a 18 months according to CarFax reports. I purchased it at around 89k miles from one of my sisters. I was in need of a car at the time and couldn't be picky. I wouldn't have paid as much in hindsight.

I can still squeeze 26/27 MPG out on the freeway, but that's doing 70MPH. Perhaps closer to 30 at 55-60 MPH.

The rev hang is due to the PCM, not the transmission. Neutral and Park are the same thing mechanically, only difference being with the gear selector in Park, the parking pawl is engaged to lock the output shaft.

Some of the things you're talking about are related to the torque converter lockup. At steady speed (usually above 30mph) the converter clutch will lock, creating a 1:1 coupling with the engine and transmission. Modern transmissions will "slip" the converter clutch enough to where it's not generally noticeable.