Do manuals coast farther then automatics?

[Baltothewolf]

Woah, thanks for the replies guys. What about with the clutch pushed in on the manual? Would that make anything of a difference?

[UltArc]

Shouldn't, but one could shift out of gear and release the clutch.

[cRiPpLe_rOoStEr]

I would expect the manual to coast a little farther in gear because it wouldn't be so slippy as an automatic, but on neutral the difference might be negligible.

Originally Posted by California98Civic

Where does the auto trans fluid pump get its power? Is it a parasitic load on the trans directly, indirectly via the engine, or more indirectly via some electrical system drawing on the battery?

I have never seen an electric ATF pump.

[UltArc]

Originally Posted by cRiPpLe_rOoStEr

I would expect the manual to coast a little farther in gear because it wouldn't be so slippy as an automatic, but on neutral the difference might be negligible.

I don't understand what this is, or how the slippiness would influence it coasting out of gear.

[mechman600]

Originally Posted by California98Civic

Where does the auto trans fluid pump get its power? Is it a parasitic load on the trans directly, indirectly via the engine, or more indirectly via some electrical system drawing on the battery?

The fluid pump is turned by the engine directly by drive teeth on the back of the torque converter body. Whenever the engine is running, the pump is being turned. I would argue that its energy consumption is negligible in the big picture, but still takes slightly more energy that a manual transmission in neutral.

This has no overall effect on coasting distance. Coasting distance is very similar between an auto and manual transmission, but you are using slightly more energy if you are idling with an automatic while doing so.

[Frank Lee]

Both a/ts and m/ts have plenty of gears, shafts, and bearings which continue to spin if the vehicle is coasting whether it's in neutral or not and whether the engine is on or off and whether the clutch is engaged or not. The exceptions are those very uncommon vehicles that can freewheel. I'm not sure, but I suspect that if the only variable is if the transmission is auto or manual, the coasting distances would be very similar.

I'm wondering what prompted the question and what will we do with the answer?

Many but not all a/ts should not be coasted extended distances with the engine off due to lack of transmission lubrication. Most m/ts are splash lubricated; the simple fact that bits are spinning in the oil lubricates them and no pump is required. So if I wanted to do extended coasting- presumably the reason I want to coast in the first place is to have the engine off to save fuel- I'd prefer to have a m/t.

Clutch in or out makes no difference whatsoever because it is on the wrong end of the transmission for disrupting the transmission-to-wheels connection.

[Baltothewolf]

Originally Posted by Frank Lee

Both a/ts and m/ts have plenty of gears, shafts, and bearings which continue to spin if the vehicle is coasting whether it's in neutral or not and whether the engine is on or off and whether the clutch is engaged or not. The exceptions are those very uncommon vehicles that can freewheel. I'm not sure, but I suspect that if the only variable is if the transmission is auto or manual, the coasting distances would be very similar.

I'm wondering what prompted the question and what will we do with the answer?

Many but not all a/ts should not be coasted extended distances with the engine off due to lack of transmission lubrication. Most m/ts are splash lubricated; the simple fact that bits are spinning in the oil lubricates them and no pump is required. So if I wanted to do extended coasting- presumably the reason I want to coast in the first place is to have the engine off to save fuel- I'd prefer to have a m/t.

Clutch in or out makes no difference whatsoever because it is on the wrong end of the transmission for disrupting the transmission-to-wheels connection.

I EoC (Engine on Coast) for a good 11-13 miles on my way home from work everyday, and I barely lose any speed while coasting, with my old Camry, I could coast for an extremely long time before I would have to accelerate again, which I now suspect was because of the heavier weight. If manuals coasted better, I could probably engine off-coast with a manual for about 8 of that if manuals coasted any better. Due to this information from all you guys, there isn't a doubt in my mind that I am getting a manual when I get the rest of the settlement from my car accident. Right now I have 800$ and am trying to find an old beater, but they are extremely hard to find in Cali due to the strict smog requirements. I can find them all day around my uncle who lives in Washington, but not here.

Here is the stretch of freeway I get to coast on. Note however, I do have to climb that everyday and I only average 28-33mpg the entire time.

https://www.google.com/maps/dir/34.3...m3!4m2!1m0!1m0


[Edit]: Only reason I don't engine-off coast now is because I enjoy my auto tranny intact.

Another edit: Here is my route to work everyday: https://www.google.com/maps/dir/1480...34.2112961!3e0

[UltArc]

It's a shame your uncle can't buy a car and you just drive it from time to time.

Wink.

[Baltothewolf]

Originally Posted by UltArc

It's a shame your uncle can't buy a car and you just drive it from time to time.

Wink.

I literally just asked my mom this last night haha, but I don't think an old beater would survive the 1,100 mile drive home from his house to my house :P

[cRiPpLe_rOoStEr]

Originally Posted by UltArc

I don't understand what this is, or how the slippiness would influence it coasting out of gear.

Coasting on neutral it would be less noticeable than coasting on gear, unless the automatic transmission has that neutral-coasting feature like the one used in the Saturn Astra.