Coasting in a Leaf

I don't own a Leaf, so excuse my ignorance for a moment. I've been reading through the threads where coasting is mentioned, what is the "R" position in a Leaf that would allow for coasting, my mind can only process R=reverse which must not be the case. Also how well does the Leaf coast, is it a freewheeling situation, or is there some regen/resistence happening at all times? Does it coast like a manual transmission vehicle would in neutral?

There is no official "coast" transmission setting or even an accelerator pedal position that is really for coasting. You can watch the "bubbles" on the dash and try to keep from showing any acceleration or regen bubbles by keeping only the single bubble showing that is intermediate between power use and regen. But that is not really coasting, there may still be some power use or regen happening.

The only real coasting happens if you shift into neutral. You can do that by pulling the shift control to the left and holding it there for a couple seconds. But then your "go pedal" is dead when you might need it to spurt out of a dangerous situation, so I don't run in neutral ever. You also get no regen even if you hit the brakes, so all braking is friction braking. Some of the expert hypermilers here use neutral regularly to extend range on long downhills, since, counter intuitively to some, regen is not efficient and can be wasteful compared to coasting.

The only real coasting happens if you shift into neutral. You can do that by pulling the shift control to the left and holding it there for a couple seconds. But then your "go pedal" is dead when you might need it to spurt out of a dangerous situation, so I don't run in neutral ever

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If one shifts into neutral, how difficult and time-consuming is it to get back in drive? Any idea if this causes any stress to the "transmission"?

+1

In addition to holding the shift puck to the left for a few seconds to get it into neutral, you can also move it into reverse (if you are traveling over 5 or 10 mph I believe) and the car will beep once and put itself into neutral. This is the fastest way to get it into neutral when driving because you don't have to hold it - but it will beep once at you.

I typically will feather the gas pedal to show put the power meter in the center ("coast") position when I know it is temporary. However, if my coast is going to last more than a few seconds I'll throw it in R to get it to go into neutral and keep my hand there for when I need to go back to drive. Seems to work pretty well. The brakes are more responsive in neutral because there is no regen that kicks in first, as there is in D & ECO.

I typically will feather the gas pedal to show put the power meter in the center ("coast") position when I know it is temporary. However, if my coast is going to last more than a few seconds I'll throw it in R to get it to go into neutral and keep my hand there for when I need to go back to drive. Seems to work pretty well. The brakes are more responsive in neutral because there is no regen that kicks in first, as there is in D & ECO.

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So getting it back into drive mode is just as simple as pulling the puck back into the drive position and it engages immediately?

gergg said:

Any idea if this causes any stress to the "transmission"?

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Nothing is changing mechanically. There is no clutch. The motor always stays connected to the drive train. You're just changing the actions of the electronics, just like you do when hitting the accelerator and brake pedals. There shouldn't really be any additional stress.

gergg said:

I typically will feather the gas pedal to show put the power meter in the center ("coast") position when I know it is temporary. However, if my coast is going to last more than a few seconds I'll throw it in R to get it to go into neutral and keep my hand there for when I need to go back to drive. Seems to work pretty well. The brakes are more responsive in neutral because there is no regen that kicks in first, as there is in D & ECO.

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So getting it back into drive mode is just as simple as pulling the puck back into the drive position and it engages immediately?

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That is it, once for D, twice for ECO. There is no transmission. It is a fixed ratio gear box without any clutching.

I like neutral coasting under certain conditions. On a freeway exit ramp, often go N, D, ECO.

Bill

Thanks....So, does it coast better going down hill in neutral than an auto ICE would in drive with no throttle? Just trying to get an idea about how effectively it will coast. Obviously it is not going to coast as freely as a manual transmission ICE car in neutral, fair statement?

gergg said:

Thanks....So, does it coast better going down hill in neutral than an auto ICE would in drive with no throttle? Just trying to get an idea about how effectively it will coast. Obviously it is not going to coast as freely as a manual transmission ICE car in neutral, fair statement?

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It feels just about the same as an ICE car in neutral.

It feels just about the same as an ICE car in neutral

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Ah, so it coasts pretty good, cool. I do lots of coasting in my VW manual TDI, so I would like to be able to include that in my Leaf driving as I imagine it would help efficiency with this car too.

gergg said:

Thanks....So, does it coast better going down hill in neutral than an auto ICE would in drive with no throttle? Just trying to get an idea about how effectively it will coast. Obviously it is not going to coast as freely as a manual transmission ICE car in neutral, fair statement?

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If it's a steep hill, you would have to use D or ECO for braking.
It may be a fair statement, but it is a false one. The reason we can coast in 'N' much longer than a manual transmission is our LLR tires. I've coasted in N for over three miles once on gradual hills and had 8.0m/kW h after just a few miles. I ended up with 7.2m/kW h after 19 miles. You would never be able to do that with an ICE unless you put LLRs on it. Also, you need to be going at least 7mph before you throw it into R to achieve N.

Also, you need to be going at least 7mph before you throw it into R to achieve N.

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Curious, why use R instead of N to get to neutral?

It may be a fair statement, but it is a false one. The reason we can coast in 'N' much longer than a manual transmission is our LLR tires

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Ok, glad to hear it coasts well, but lots of cars use LLR tires, just saying.....unless these are super-duper LLR tires? Not looking to argue, happy to hear about the coasting ability I'll definitely use it.

gergg said:

Curious, why use R instead of N to get to neutral?

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Because you need to hold the switch in N for few seconds before it actually flips to N, If you hit R Leaf will put you in N right away (unless you are going slowly than 7mph)

gergg said:

It feels just about the same as an ICE car in neutral

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Ah, so it coasts pretty good, cool. I do lots of coasting in my VW manual TDI, so I would like to be able to include that in my Leaf driving as I imagine it would help efficiency with this car too.

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I like diesels but I don't know that much about them. Wouldn't it be similar to fuel-injected gas engines where it actually burns gas if you leave it in N as opposed to leaving it in a higher gear where it doesn't burn gas at all? For true fuel savings, I'd turn it off and let it roll! Good workout too...

I question that... My BMW 3 series with stick coasted almost as well as my Leaf at highway speeds... LRR tires do make some difference but it is not actually that significant compared to the modern tires on most passenger-like vehicles these days, particularly at higher speeds since tire rolling resistance is pretty much a constant regardless of speed and thus a smaller percentage of total drag as speed increases. I believe more of the small difference is the higher drive-line drag in a ICE, even with a manual transmission in neutral, and the lower over-all aerodynamic drag of the Leaf.

LEAFfan said:

The reason we can coast in 'N' much longer than a manual transmission is our LLR tires.

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cracovian said:

gergg said:

It feels just about the same as an ICE car in neutral

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Ah, so it coasts pretty good, cool. I do lots of coasting in my VW manual TDI, so I would like to be able to include that in my Leaf driving as I imagine it would help efficiency with this car too.

Click to expand...

I like diesels but I don't know that much about them. Wouldn't it be similar to fuel-injected gas engines where it actually burns gas if you leave it in N as opposed to leaving it in a higher gear where it doesn't burn gas at all? For true fuel savings, I'd turn it off and let it roll! Good workout too...

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If I need engine braking, I'd just use eco, and instead of turning engine off and fighting for your deer life, I'd use regen and actually get some stuff into the battery rather then spend energy heating air by compressing it in cylinders or just doing nothing. So, I like electric better than diesels and fuel-injected gas engines

I like diesels but I don't know that much about them. Wouldn't it be similar to fuel-injected gas engines where it actually burns gas if you leave it in N as opposed to leaving it in a higher gear where it doesn't burn gas at all? For true fuel savings, I'd turn it off and let it roll! Good workout too

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Yes, they burn fuel when coasting in neutral(not much though), but I prefer that to coasting in gear as it rolls forever. I never turn off the engine. I've never had a car coast as well as my VW Passat 6M TDI, this thing is amazing, if the Leaf coasts as good as the VW then I will be a happy camper.

The LEAF is amazing with its different coasting options as described by everyone but what makes it 'better' is its very low drag coefficient and hundreds of pounds of batteries sitting under the floor. If the car were made smaller into a size of a scout derby car it would dominate the races

cracovian said:

The LEAF is amazing with its different coasting options as described by everyone but what makes it 'better' is its very low drag coefficient

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It's not that low... About .29 compared to modern Prius of .25.

It rolls well because there's very little drag in the power train.

At some airspeed, there has to be a cutover point where you're better off putting that downhill energy "into the bank" with regen, since air drag increases exponentially and will prevent you from storing it all as momentum; bleeding it off into air turbulence instead.