Car off coasting theory questions

[SVOboy]

Did a bit of this yesterday and I must say it was quite exhilirating, I must say. However, I only did it on my way to a complete stop because I've got a few questions.

How does this junk work with an auto?

And, do the people who do this usually do it to a long light or just down a hill or what. I'm planning on turning the car off at some of these lights I hit now, and was thinking this stuff would be good to combine.

[iburnh2o]

Dont do it with an 'auto' .. pump not running will cause catastrophic failure.

[MetroMPG]

please be careful about making blanket statements.

some saturn automatics are perfectly OK coasting with engine off - it's why they're such popular tow-behinds for RVs. it may be bad for many/most automatics, but not necessarily for all. you need to know your particular vehicle's specifics.

nevertheless - if your 'auto' is a non-coaster SVOboy, just coast to the stop with the engine idling. the torque converter is still spinning, so lubrication isn't an issue, and it's still more efficient than coasting down in gear, because there's no engine braking, and injectors are pulsing at a lower rpm. plus you retain power steering, and have more than "reserve" vacuum for braking (compared to engine off).

as for "does this junk work with an auto", yes, absolutely. have a look in the pulse & glide thread (long). one of my last comments is about a driver who is getting phenomenal mileage coasting in neutral with his accord automatic non-hybrid.

thread link

[Compaq888]

my auto coasts very good in neutral, the hassle is the brakes don't work and the power steering. Not to mention if I want to start the car back up it has to be a complete stop or in Neutral.

[SVOboy]

plus you retain power steering, and have more than "reserve" vacuum for braking (compared to engine off).

I have no power steering, power steering = sucks. Also, I've got no power brakes either (think the bb is busted), so yeah.

as for "does this junk work with an auto", yes, absolutely. have a look in the pulse & glide thread (long). one of my last comments is about a driver who is getting phenomenal mileage coasting in neutral with his accord automatic non-hybrid.

Pulse and glide will not work for me, I can't shift into neutral becaause shifting back into gear while moving won't work. The newer honda autos have seemless shifting while driving, but I don't. When I swap to manual it won't be an issue, I should say.

[Matt Timion]

Originally Posted by SVOboy

Pulse and glide will not work for me, I can't shift into neutral becaause shifting back into gear while moving won't work. The newer honda autos have seemless shifting while driving, but I don't. When I swap to manual it won't be an issue, I should say.

You should be able to shift while in motion. Maybe something is wrong with your tranny?

[MetroMPG]

Originally Posted by SVOboy

Pulse and glide will not work for me

sure it will - just not at higher speeds. coasting up to a stop in neutral counts as "gliding".

10 minutes ago, i drove through a typical subdivision where there's a stop sign on each corner. i accelerated about 30% of the way down the block, then shifted to neutral to coast the rest of the way to the next intersection. that's pulse and glide. some people call it porpoising.

the technique isn't exclusively for higher speeds. it can be applied in lots of situations.

[SVOboy]

sure it will - just not at higher speeds. coasting up to a stop in neutral counts as "gliding".

10 minutes ago, i drove through a typical subdivision where there's a stop sign on each corner. i accelerated about 30% of the way down the block, then shifted to neutral to coast the rest of the way to the next intersection. that's pulse and glide. some people call it porpoising.

the technique isn't exclusively for higher speeds. it can be applied in lots of situations.

Ah, okay, I do that, I meant the 15 second/15 second cycle thing by pulse and glide, I coast plenty as it is, , sorry for the confusion.

[SVOboy]

You should be able to shift while in motion. Maybe something is wrong with your tranny?

I can shift, but in motion (25 mph +) shifting from neutral into drive I get lots of engine braking because the tranny doesn't gear/rev match.

[diamondlarry]

And, do the people who do this usually do it to a long light or just down a hill or what. I'm planning on turning the car off at some of these lights I hit now, and was thinking this stuff would be good to combine.

I normally do this when I'm coming to a stop sign. It's kind of tricky to do it at lights unless you know the light really well. A lot of our lights in my area are based on traffic flow so they change whenever a car approaches. This can be a pain if they come from out of nowhere and you don't have time to coast to a stop. If you have an automatic you have to keep in mind that if you shut the engine off, you are going to put more wear and tear on your starter. I generally pop the clutch(usually in 4th gear at around 15 mph) just before I get completely stopped so I don't have to use my starter as much. I don't have power steering so I don't have to worry about loss of handling. I haven't noticed any problem with braking either.