Nissan LEAF electric motor and transmission

by Ernie Hernandez on November 1, 2010

Nissan LEAF motor assembly

So… how does a LEAF work?

We’re not really going to tell you how a LEAF works. But… we will give you a little insight into how the LEAF is different from the car that you are currently driving.

Recently, the good folks in Nissan’s European Newsroom provided us with some additional technical specifications for the LEAF that had not been previously released. For instance, we now know that the AC synchronous motor can turn a maximum of 10,390 revolutions per minute (RPM). We heard from some other sources as much as 18,000 RPM, but thought that might be on the high side. And most likely, you have heard by now that LEAF does not use a conventional automatic or manual transmission. It uses a single speed reduction gear with a final drive ratio of 7.9377. So what good does that do anyone? Good question. Divide 10,390 by 7.9377. Go ahead… we’ll wait. Come up with 1308.94? Good! So did we.

1308.94 is how fast the tires will rotate when the motor is turning the maximum 10,390 RPM. Why is this important? Because, since we know that the tires are a Bridgestone Ecopia model, size 205/55R16, we know that the tires have a diameter of 24.9″ and will turn 837 revolutions per mile (not per minute). With these givens, at 60 miles per hour these tires will turn 837 RPM. But if the electric motor is turning 10,390 RPM, and the tires are turning at 1308.94 RPM, how fast are we going? Simple… do the math!

1308.94 RPM divided by 837 RPM equals 1.56. So at maximum motor RPM, we are traveling at 1.56 times 60 MPH, or 93.8 MPH. We think that we recall reading that the fastest the LEAF has traveled (at least in road tests that we have seen) has been 94 MPH or 95 MPH, so these calculations are probably fairly accurate. Here at Living LEAF we’re car geeks… what can we say?

Some other numbers released: curb weight 1,525kg (3,355 pounds) minimum 1,595kg (3,509 pounds) maximum. These are based on some European spec that we are not familiar with, but we expect US numbers to be similar. The variance is likely due to the trim level and associated equipment differences.

One other little bit that we picked up – both front and rear brake rotors are ventilated. Typical practice on compact cars is to provide vented front rotors and solid rear rotors. Venting the brakes at both ends of the car offers several advantages – cooler brake operation, longer component life, improved performance, along with potentially less maintenance. This is the type of treatment typically found on more expensive performance oriented vehicles. Nice to see on the LEAF.

{ 21 comments… read them below or add one }

Neil Bettenhausen February 7, 2011 at 6:56 am

Very interesting. Thanks for posting. Now I can tell my friend who drives a Hummer that my car rev’s up much higher than his! And….I can start out in “high” gear, without shifting.

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Ernie Hernandez (LEAFguy) February 7, 2011 at 8:40 pm

Isn’t it amazing what knowing a few facts can do?! :)

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Tim July 18, 2011 at 3:39 pm

Excellent Information.. This Clears up many Forum Battles! I am excited to see these Babies rolling around Canada, and Charge Stations Emerging.. Keep them coming Nissan, You are Top Notch for bringing these out!!

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Ernie Hernandez (LEAFguy) July 20, 2011 at 5:54 pm

Tim – welcome to Living LEAF. Hopefully, you will continue to find our site of service. My whole goal is to get good info out in the world about the LEAF and EVs in order to help encourage their adoption.

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Eric September 4, 2011 at 7:12 pm

Still a weak autonomy though.I’ll buy an electric car when the 500 Km autonomy range will be a reality.

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Ernie Hernandez (LEAFguy) September 5, 2011 at 8:54 pm

Eric, welcome to Living LEAF. Nissan’s LEAF is not an everyman car – yet. This is what will make cars such as the plug-in Prius hybrid and Chevy Volt more attractive to those interested in going electric, but needing a greater range than that currently offered by the LEAF. We likely will not see 300 mile range anytime soon from any pure battery electric vehicles carrying a LEAF price tag. If you do wish to go full electric and wish to achieve that range, you can look into the Tesla Model S sedan. The Model S is slated to be available next year and will offer the 300 mile range that you seek. Tesla’s first vehicles produced will be the top of the line Signature model, which will require a premium over the standard $70,000 300 mile model. Pricing has not yet been announced for the Signature model.

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jeff b September 18, 2011 at 9:12 pm

Test drove a leaf this weekend. Its peppy and cute. But small and with very limited range. Not the sort of car that most americans would consider spending over $20,000 on. The lack of gas is great but, I only was projected to have an 87 mile range by the car (not in economy mode, driving normally, without hypermiling sort of tricks). 87 mile range is just too limiting to make this useful as a viable transportation option, unless its only a “spare” car for local errands. After seeing how small the battery pack is in the traveling demonstration currently on tour, it seems that nissan could’ve doubled up on the cells; and gave america a 200 mile range vehicle that would be a truly reasonable choice (if done with a price of around $30,000). Anyways…it seems to me that the first manufacturer to produce THAT vehicle is the one who will be the “winner”, i.e. the first one to have a practical ev that americans will start purchasing in mass. Still, we needed to start down the road to electric cars somewhere, and nissan is to be congratulated for being the first horse out of the gate. I hope the race is run well.

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Ernie Hernandez (LEAFguy) September 19, 2011 at 10:33 pm

jeff – we replied to your comment in another post regarding many of the topics you raised here. You say that if Nissan could have created an EV that went 200 miles for $30,000 they would have a winner. The fact of the matter is, no one can produce that car currently. Not Nissan, GM, Tesla, or any of the other manufacturers coming out with electric vehicles in the next few years. Five to ten years from now? We’ll see.

As you say, “we needed to start down the road to electric cars somewhere…” Nissan has done exactly that.

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Justin H January 9, 2013 at 11:55 am

+1 to that Ernie. Even though the car cant make it around the globe in one charge, the fact this car is ground breaking technology. Its comfortable, can take the family around town and highly economical…there is nothing bad you can say about the car…well maybe the looks, but a fugly car is still cool to drive and I Do enjoy it.

Nissan started, hopefully they keep up with the technology and advancements while others (like VW Now looking to do a full EV Golf) might leave NISSAN in the dust.

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Varun Bhatia January 3, 2012 at 10:39 pm

Hey,
I am Officially the First Leaf owner in New york. i currently live in New hyde park and because i couldn’t wait to order one i purchased one from Portland and it will be shipping in 2 to 3 days finally waited over 13 days for delivery due to xmas and new years. Well my point is i plan on driving my leaf atleast 40 miles a day and up to 70 miles a day. I live in the border of queens and long island. My location is optimal for the range of the leaf. I am 24 miles from manhatten and 24 miles from most parts of Long island like the school i plan on going to SunyFarming dale and then NYIT which currently has a EV Solar charging station. I will keep everyone updated on my range and i have a gas car for when i am low on batt. I can just leave the leaf at home and pick up my ice for further driving. I often go past my house to go from long island to queens and visa versa. For example i go to car meets in Long island but i drop my mom to work very often in Astoria, Queens. so depending on where i go first i can stop by my house to switch cars. My current ICE vehicles a 1996 miata 22mpg but only 87 octane. I also own a 2003 maxima with 187,000 miles on it with about 16 mpg on 93 octane. I bought the car New and have driven it from 2004 to the present yes that is why i bought a leaf. even if i cut my miles to half i save about 200 to 250 dollars a month in gas making my leaf $320 per month instead of the 520 i pay post tax rebate. So I feel if the leaf is your second car there is plenty of room for a leaf as your second car. I can even charge it at School as they will be happy to help, this will extend my leaf driving even further. My final plan is to get a Range extender trailer which i can use to say go to Florida or Canda in the car as opposed to taking my Maxima. then i will get about 35 MPG on an the worst setup and that’s not too bad for once in a while and still better MPG then most cars out today. ok well sorry for the long post if you have read this much then i hope you guys will read my updates on how well the LEAF experiment is doing in my household.

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Ernie Hernandez (LEAFguy) January 4, 2012 at 10:09 am

Varun – Welcome to Living LEAF. We are pleased to hear about your experience, as it will help others that may be in a similar situation. We would love to hear from you with additional comments as you experience your new LEAF. Congratulations!

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Gadge January 17, 2012 at 5:14 am

My calculations, however, show that the circumference for that tire size is 78.16 inches divided into a 63,360 inches/mile yielding 811 revolutions which gives a factor of 1.61 with a theoretical top speed of 97MPH.
There’s therefore a discrepancy between your posted numbers and mine…could you show the details of your calculations.
Thanks

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Ernie Hernandez (LEAFguy) January 17, 2012 at 11:50 am

Gadge – welcome to Living LEAF. All of my calculations are included in the article.The difference between our top speed is the revolutions per mile. I used 837 (as indicated in the link to Tirerack.com (Tire Rack tire size info)). You used 811 based on circumference. There’s the difference. Using your circumference number results in a top speed of 96.8 vs. my calculated 93.8. But when it really comes down to it, does it matter to the majority of LEAF owners how fast their car can go? In daily driving, most will rarely, if ever, exceed 80 miles per hour. In over 6 months we have not yet personally explored the top speed of our LEAF. Perhaps we’ll put that on our agenda. Thanks for the idea!
.

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Gadge January 19, 2012 at 8:02 am

Ernie,
I found the reason for the discrepancy. When tire manufacturers report ‘revolutions per mile’ in the specs, depending on the tire, a 3-5% ‘slippage factor’ is applied. In this case adding 3.2% to my calculated 811 RPM yeilds 837 as reported for the Bridgestone Ecopia which is a more energy efficient ‘low resistance to roll’ tire.

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Ernie Hernandez (LEAFguy) January 19, 2012 at 9:51 pm

That makes sense. I figured there was some reason for the difference, but I wasn’t quite sure why. Now we both have the answer. Thanks for checking it out.

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Jonathan November 12, 2012 at 7:13 pm

How does the leaf deal with turning and wheel rotation speeds? Other cars use things like a limited slip differential (http://en.wikipedia.org/wiki/Limited-slip_differential). Presumably the leaf must solve this problem (unless it delivers all power through a single wheel).

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Ernie Hernandez (LEAFguy) November 12, 2012 at 8:42 pm

Hi Jonathan – Welcome to Living LEAF. You are almost right. While some performance cars (think Mustang, Camaro or 370Z) use a limited slip differential to help put the power to the ground instead of just spinning your wheels, most cars (including the LEAF) use a regular open (or non-limited slip) differential (wiki article found here). The difference is that with an open differential, its primary job is to allow one tire to rotate faster than the other to corner smoothly and not break anything. A limited slip differential will sense the spinning wheel in a high powered car if excess power is applied too quickly and literally limit slip of the spinning wheel and send that power to the wheel that has traction. Here’s a great page of articles on the How Stuff Works website (found here) that explain how they work. I hope that helps.

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Elroy February 9, 2013 at 5:32 pm

I instrumented my 2012 LEAF with a racelogic GPS unit (Very Accurate).
91.7mph maximum speed.

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Ernie Hernandez (LEAFguy) February 9, 2013 at 6:49 pm

Elroy – Welcome to Living LEAF. And thanks for the feedback!

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Laurie September 19, 2014 at 9:06 am

For those of you with “range anxiety” – Note that most people do not drive more than 30-50 miles in a day. The LEAF is perfect for running errands, getting your kids to school, short commutes, etc. Or, even if your commute is a little longer, you might be able to charge up at work or nearby. The benefits of the LEAF are endless, starting with the most important: ZERO emissions. No burning of fossil fuel. If you live in Seattle like we do, the extra benefit is that the electricity we use is clean energy. Or you can set up a solar panel just for charging your car. Instead of paying $100 – $125 per month per gas, we pay about $25 or $30 per month for electricity. No oil changes, no trips to the gas station, and hardly any moving parts to maintain – no fuel injection system, carburetor, etc. No oil dripping in your carport or on the roads. No obnoxious fumes. no idling. quiet, smooth, gliding ride.

If the range anxiety is too much for you, consider the LEAF as a second car. you will soon find that you think of it as your FIRST car. It is so much nicer to drive than an ICE (internal combustion engine).

And did I mention – no emissions? We are destroying life on earth as we know it by burning fossil fuels – this is one step you can personally take in the other direction. Its worth a bit of inconvenience.

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Ernie Hernandez September 19, 2014 at 9:12 am

Laurie – Welcome to Living LEAF. And thank you for your comment. As your personal experience shows, the fuel cost savings is significant when one moves from gasoline to electricity. A savings of 60 percent to 70 percent is not uncommon due to the efficiency of an electric motor over a gasoline engine and the lower cost of electricity compared to gasoline. Also, some individuals are fortunate enough to work at a company like Qualcomm, Google, or many others, that offer employees the ability to charge their LEAF at work. My wife loves the fact that she doesn’t have to go to the gas station anymore also. Thanks again.

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