Glide vs coast?

You will be the happiest with your new car if.........you just DRIVE it, using some common sense and not worrying about all of this hyper-milling crap.

Your attention should be on the road and traffic conditions around you. Getting an extra .5 MPG will be pretty meaningless if your brain is tied up worrying about THAT and you crash into something.

 

I think @Sam Spade is right, but to answer your question, you take your foot part way off so that you are neither propelling the car or regenerating the battery when you glide, i.e.: no arrows to or from the battery. When you coast, you take your foot all the way off the gas pedal and your car will decelerate relatively quickly as it regenerates power for the battery.

I messed around with pulse and glide for a couple months a while back. I could not improve on just driving it sensibly (which is quite different from the people who pass me at 90 mph just so they can burn more gas getting to the obviously red light quicker so they can burn more gas idling longer at the light).

 

i have been pulse and gliding my wife's hycam here in florida. i can pick up 2-4 mpg depending on trip length and traffic. right now, we're at 45 mpg on the meter, about 400 miles into the tank.

 

Asked and answered.

Sam is right though.....
It's easier to just hypermile like you would with a regular car.

See also: Law of diminishing returns

 

The only thing about hyper-mileage driving, is pay attention to the road, not the gauge! Watching the ECO meter all the time is distracting and could cause an accident. If you use it for a while you can learn how the car reacts to throttle pressure and not look at it so much.
Have you seen the commercial for the insurance company, the guy's head sticking out where the GPS display would be, Mr. Chaos? Not really funny, but very true, she can't stop playing with his face (the display).
Gasoholic

 

hate to nit pick, but i don't see why gliding is like shifting into neutral. this isn't the first time i've heard this comment, but i feel like it implies that shifting into neutral in a normal non-hybrid would be more efficient than leaving it in drive--which it technically isn't. I mean we're not arguing by much, but ceteris paribus, coasting in neutral in a non-hybrid post-90s car uses more gas than leaving it in drive. Gliding, from how i understand it, is driving in a manner that doesn't charge or recharge the battery. Efficient, but definitely not neutral.

 

it is neutral for a prius. gassers are different, but prius neutral is just easier. you don't have to watch the hsi or try to feather the pedal, which is almost impossible.
that being said, the unknown quantity is the most efficient rpm's for pulsing.

 

It's as neutral as you can get anyway.

 

exactly.

 

ah ok, so when likening gliding to neutral, we're talking hybrid neutral, not ICE-car neutral. got it

 

right. trying to adjust the gas pedal and paying attention to traffic is difficult, and possibly dangerous. you're always regaining a bit (bad) or powering a bit (not so bad). in neutral, it's done, but may be illegal. (really bad)

 

So here's the thing for me:
These vehicles are designed to RECOVER some energy when slowing down or stopping.

For this "glide" thing to work for a net gain, you would almost have to be psychic so that you would KNOW EVERY TIME if you really were going to have to slow down a significant amount or not.

So that leaves conditions when you are "cruising". During the glide phase, you slow down which you must recover from by expending energy.
The whole thing seems like the driver is expending more of HIS energy that what he might save with the engine.

OCD at it's worst, IMHO.

 

In a conventional vehicle changing into neutral prevents fuel-cutoff so it's a trade-off between the extra friction of the car's inertia being used to rotate the engine or the fuel used by the engine while in neutral to keep it running. If you have a car with automatic stop-start it may be better to put it in neutral.

With the Prius you need to change into neutral AFTER the engine shuts-off then you can get gliding without having to finely balance the throttle.

kevin

 

In a normal non-hybrid, it depends on the circumstances. I'll restrict this answer to manual transmissions, not automatics, i.e. no D gear. Except for the Prius, my household fleet has been strictly manuals for more than three decades.

N-ICE-OFF (neutral, ICE shut off) is much more efficient than coasting in gear. No fuel use, no engine drag. It is used only by the hardest core hypermilers.

For the easier and more common N-ICE-ON (ICE operating), it depends. The driver is trading off the fuel needed to spin the ICE at idle speed, versus the energy loss of engine drag needed to spin it in fuel cutoff mode. With traditional gear ratios at highway speed, that spin RPM can be fairly high, thus costing more energy than actively burning fuel at much lower RPM.