EPA: Nissan Leaf gets 99 mpg equivalent

[LEAFfan]

For comparison, the EPA rating for my 2008 Tesla Roadster to 26 kWh/100 mile city and 29 highway with a range of 244 miles.

I find that if I drive at a steady 55 mph on level freeway, I get energy use consistent with the 244-mile range. My best test of this was in March 2010, when I drove 182 miles at 55 mph and had 60 miles of range showing at the end of the drive. If I drive 70 mph, it's more like 175 miles.

Like the Leaf, the Roadster has two charge modes. Range mode gives you the full usable capacity of the battery pack and the full range. Standard mode gives you access to the middle 80% of the battery pack and about 195 miles at 55 mph.

After about 18 months and 14,000 miles, the range mode capacity has dropped to 234 and standard mode to 183, for a loss of about 5% of the range. Tesla has muddied the waters here by changing the way the firmware calculates the capacity of the battery, in a way that dropped the estimated range shown on the screen, so it's possible the loss in range is not as large as the reported numbers indicate.

In terms of power, I very slightly bested my quarter-mile time from last year, 12.978 seconds July 2010 vs. 12.982 seconds July 2009. I believe I've improved my launch technique, so it's possible the battery pack has lost a little bit of power, but is seems smaller than the loss in energy capacity.

In terms of day-to-day driving in standard mode, if I'm driving under 150 miles I don't even have to think about charge. I can drive however I like without regard to efficiency. For drives this short, the Roadster is completely care-free. Driving 180 miles, even in range mode, requires paying attention to your speed and often going below the posted speed limit on freeways. When driving to maximize range, I've changed my driving to take state highways with speed limits of 60 mph or less instead of 70 mph freeways, and optimize routes for distance. I like driving this way, the routes generally have more varied scenery and less traffic.

I'm assuming the EV range test hasn't changed from when the Roadster was tested in late 2008. From that, I have to assume that it will take some careful driving to get 73 on the freeway. In the 80% mode, it will take careful driving to get 58 miles of range, and 45 miles will be the range you can get in the 80% mode without needing to think about charging.

The most unhappy Roadster owner I know drives 200 miles per day on a regular basis. The only EV1 owner I've ever heard complain about the experience had one of the early lead-acid models with a 75-mile range and drove a 74-mile commute. I think a Leaf driver trying to get over 60 miles without charging on a typical day will be unhappy and anyone trying to get 73 miles regularly will become a vocal EV detractor. If you have Level 2 charging at home and can also charge at work, you can probably push up to 80 (120V charging) or 120 (Level 2 charging) miles.

If you're not sure these range numbers will easily meet your driving needs, I strongly urge you not to be one of the first Leaf owners. Wait until we have lots of real people reporting their actual driving experience so you can determine if the car really meets your needs.

My wife and I are pretty early in the list by order date, so I expect will get ours early in the process. We'll test the car and report what we find to the community.

I may believe the 45 miles figuring if it included A/C on or heat. Otherwise, I know I can do better than that since I rarely use A/C or heat. I plan on 80% charging to keep the batteries in better shape.

 

[lne937s]

For comparison, the EPA rating for my 2008 Tesla Roadster to 26 kWh/100 mile city and 29 highway with a range of 244 miles.

I find that if I drive at a steady 55 mph on level freeway, I get energy use consistent with the 244-mile range. My best test of this was in March 2010, when I drove 182 miles at 55 mph and had 60 miles of range showing at the end of the drive. If I drive 70 mph, it's more like 175 miles.

Like the Leaf, the Roadster has two charge modes. Range mode gives you the full usable capacity of the battery pack and the full range. Standard mode gives you access to the middle 80% of the battery pack and about 195 miles at 55 mph.

After about 18 months and 14,000 miles, the range mode capacity has dropped to 234 and standard mode to 183, for a loss of about 5% of the range. Tesla has muddied the waters here by changing the way the firmware calculates the capacity of the battery, in a way that dropped the estimated range shown on the screen, so it's possible the loss in range is not as large as the reported numbers indicate.

In terms of power, I very slightly bested my quarter-mile time from last year, 12.978 seconds July 2010 vs. 12.982 seconds July 2009. I believe I've improved my launch technique, so it's possible the battery pack has lost a little bit of power, but is seems smaller than the loss in energy capacity.

In terms of day-to-day driving in standard mode, if I'm driving under 150 miles I don't even have to think about charge. I can drive however I like without regard to efficiency. For drives this short, the Roadster is completely care-free. Driving 180 miles, even in range mode, requires paying attention to your speed and often going below the posted speed limit on freeways. When driving to maximize range, I've changed my driving to take state highways with speed limits of 60 mph or less instead of 70 mph freeways, and optimize routes for distance. I like driving this way, the routes generally have more varied scenery and less traffic.

I'm assuming the EV range test hasn't changed from when the Roadster was tested in late 2008. From that, I have to assume that it will take some careful driving to get 73 on the freeway. In the 80% mode, it will take careful driving to get 58 miles of range, and 45 miles will be the range you can get in the 80% mode without needing to think about charging.

The most unhappy Roadster owner I know drives 200 miles per day on a regular basis. The only EV1 owner I've ever heard complain about the experience had one of the early lead-acid models with a 75-mile range and drove a 74-mile commute. I think a Leaf driver trying to get over 60 miles without charging on a typical day will be unhappy and anyone trying to get 73 miles regularly will become a vocal EV detractor. If you have Level 2 charging at home and can also charge at work, you can probably push up to 80 (120V charging) or 120 (Level 2 charging) miles.

If you're not sure these range numbers will easily meet your driving needs, I strongly urge you not to be one of the first Leaf owners. Wait until we have lots of real people reporting their actual driving experience so you can determine if the car really meets your needs.

My wife and I are pretty early in the list by order date, so I expect will get ours early in the process. We'll test the car and report what we find to the community.

I may believe the 45 miles figuring if it included A/C on or heat. Otherwise, I know I can do better than that since I rarely use A/C or heat. I plan on 80% charging to keep the batteries in better shape.

The 47 mile worst case figure was with the AC in heavy stop and go traffic averaging 6 mph. In otherwords, if you run the AC for 8 hours traveling 47 miles, it will consume the battery. This is highly unlikely conditions for most drivers. Driving at top speed will not reduce range as much as 6 mph stop and go traffic with the AC on.

http://green.autoblog.com/2010/06/14/nissan-pegs-leaf-range-between-47-and-138-miles-individual-resu/

 

[lne937s]

Why the EPA range figure is wrong:
http://www.allcarselectric.com/blog/1051877_why-the-epa-is-wrong-about-the-2011-leaf-range-and-nissan-is-right?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+AllCarsElectric+%28All+Cars+Electric%29

 

[LEAFguy]

While anyone can debate how and why the EPA came up with what they did, all one needs to do is to "do the math". In order to get a range of 73 miles, the LEAF averaged 3.04 miles per kWh. It has already been shown in many driving environments that this number can easily be exceeded. If your driving uses more energy than this, you will get less than 73 miles per charge. If your driving uses less energy than this, you will get more than 73 miles per charge.

 

[Smidge204]

While anyone can debate how and why the EPA came up with what they did, all one needs to do is to "do the math". In order to get a range of 73 miles, the LEAF averaged 3.04 miles per kWh. It has already been shown in many driving environments that this number can easily be exceeded. If your driving uses more energy than this, you will get less than 73 miles per charge. If your driving uses less energy than this, you will get more than 73 miles per charge.

It can't be overstated that driving habits and conditions have a MUCH bigger impact on range than they do with gasoline engines.

"The math" is rather difficult to do since there are a lot of considerations to be made. For example, it's obvious that the faster you drive, the more power you need to draw to overcome rolling and air resistance to maintain speed... but it's not so obvious that the more power you draw from the battery, the less efficient the battery is. Lithium batteries do not suffer from this nearly as much as other types, but they still have that problem. Charge state and temperature also affect battery efficiency. Motor/inverter efficiency also varies with load and speed. Probably not much, but it all adds up quickly.

The EPA number is probably not that bad in terms of planning estimates; it represents a pretty harsh driving cycle. I think the real advantage of EVs is that they make the user more conscious of their vehicle's energy use, so they are subconsciously compelled to use it more efficiently. If people go in expecting the EPA numbers they are likely to quickly realize that adjusting their habits (like actually driving the speed limit!) will greatly improve range, and they will be happier for having their expectations exceeded.

Chances are, people buying or interested in EVs will already know this intuitively so I guess I'm preaching to the choir here
=Smidge=

 

[garygid]

There are LOTS of EV-newcomers, and even most "enthusiastic" first-time EV buyers have a lot to learn. Even the "choir" can learn new songs!

 

[DaveinOlyWA]

From the all cars electric news letter
http://www.allcarselectric.com/blog/1051877_why-the-epa-is-wrong-about-the-2011-leaf-range-and-nissan-is-right

They dies the EPA test extensively. Now these are people who seem to imply that they have tested the ra.ge and are not seeing ranges under 80 miles when very long drive times are not involved

 

[Dino]

http://blogs.forbes.com/warrenmeyer/2010/11/24/the-epas-electric-vehicle-mileage-fraud/

" They did this be dividing the potential energy or heating value of a gallon of gasoline (115,000 BTUs) by the energy in a KwH of electricity (3412 BTUs) to get a conversion factor of 33.7 gallons per KwH."

WOW, forget the Leaf, gimme a Hummer.

 

[Frank]

Regarding the EPA tested range of 73 miles. Is that estimate based on a 100 percent full battery charge? If so, if the Leaf battery pack was charged to the 80 percent Nissan recommended level would that mean an EPA range of 58 miles (73 x 80%)?

 

[Gonewild]

If I had to guess it is based off the 80% because the EPA would use the manufactures recommended use as their starting baseline. I could be wrong but it make more sense and would show in the results.

 

[cdub]

If I had to guess it is based off the 80% because the EPA would use the manufactures recommended use as their starting baseline. I could be wrong but it make more sense and would show in the results.

I doubt it. The EPA range is on track to what nissan had beed saying re highway speeds which is probably what their test simulates.

 

[garygid]

Frank,
Likely correct.
If charging to 100% (of usable) gives you 80 miles under certain driving conditions, then an 80% (of usable) charge should give you 80 x 0.80 = 64 miles (with the same driving style).

 

[Frank]

Frank,
Likely correct.
If charging to 100% (of usable) gives you 80 miles under certain driving conditions, then an 80% (of usable) charge should give you 80 x 0.80 = 64 miles (with the same driving style).

After 5 years of battery pack use should we expect to have 46 miles of range based on the EPA rating and Nissan's estimate of a 20% degradation of the battery pack (73 x 80% x 80%)? Of course this assumes that the EPA estimate of 73 miles range is accurate. But I think the EPA estimate will be accurate for the general population that plans to use AC and heat while driving at freeway posted speed limits.

 

[garygid]

Yes, apparently EPA x <charging-%-fraction> x <capacity-%-fraction> would seem to be a "realistic" real-use expectation of range.

It is not clear to me how the EPA gives an apparently-better figure to the Volt's E-Only mode.

Also, apparently the 5-year capacity loss might be 30% (or 40%, or even more), not just 20%.

Currently, it seems that Nissan does NOT warranty ANY amount of "gradual capacity" loss. With heavy usage (perhaps charging twice a day) might the capacity loss be as bad as 20% loss PER YEAR?

 

[planet4ever]

It is not clear to me how the EPA gives an apparently-better figure to the Volt's E-Only mode.

Apparently better on what basis? You're not still assuming an 8 kWh or even 10 kWh battery usage, are you?

The EPA says the Volt goes 35 miles and uses 36 kWh per 100 miles. 35*36/100 = 12.6 kWh being used in the battery.

The number to look at is that the Volt (in E-mode) uses 36 kWh/100 miles and the LEAF only uses 34 kWh/100 miles.

 

[Smidge204]

Hopefully light can be shed on this within a few months, since the EPA publishes their test data... eventually.

I wonder if a FOIA request would speed things up a bit. You could probably get more detailed information (exact test procedures?) with that method as well. I think I'm gonna write one up.
=Smidge=

 

[Spies]

Regarding the EPA tested range of 73 miles. Is that estimate based on a 100 percent full battery charge? If so, if the Leaf battery pack was charged to the 80 percent Nissan recommended level would that mean an EPA range of 58 miles (73 x 80%)?

Please forgive my ignorance but what "charged to the 80 percent Nissan recommended level" are you guys talking about? I am only aware of the 80% figure when it comes to doing an L3 quick charge. The EPA sticker does show it took them 7 hours to charge from empty to full on 240V for their testing and does not mention L3 at all or even L1 for that matter.

 

[Frank]

Regarding the EPA tested range of 73 miles. Is that estimate based on a 100 percent full battery charge? If so, if the Leaf battery pack was charged to the 80 percent Nissan recommended level would that mean an EPA range of 58 miles (73 x 80%)?

Please forgive my ignorance but what "charged to the 80 percent Nissan recommended level" are you guys talking about? I am only aware of the 80% figure when it comes to doing an L3 quick charge. The EPA sticker does show it took them 7 hours to charge from empty to full on 240V for their testing and does not mention L3 at all or even L1 for that matter.

Nissan made a recommendation about increasing battery life by charging to 80 percent of battery capacity rather than 100 percent. The charger timer can be set to charge to 80 percent or 100 percent. I can't remember where Nissan made this recommendation but perhaps someone else can provide the source.

 

[Coffee_Slurry]

Nissan made a recommendation about increasing battery life by charging to 80 percent of battery capacity rather than 100 percent. The charger timer can be set to charge to 80 percent or 100 percent. I can't remember where Nissan made this recommendation but perhaps someone else can provide the source.

100% Charge: "Lease charge" Full range, reduced long-term battery lifespan. See also: DC Quick Charge, wilted flowers, opportunistic top-off.
80% Charge: "Owner charge" 20% less range, longer battery life. See also: hypermiler, L2 only, "20-80" band.

 

[garygid]

Apparently the LEAF has a stop-charging selection of 80% or 100% (of "usable", not "total).

The manual seems to recommend NOT re-charging frequently to 100% if the battery is only "a little" discharged ... without a good description, or why.

This would probably apply to driving a few miles to a store, plugging in to recharge, driving another couple of miles to a mall and plugging in again, and driving a "little" back home (charging again), then later that day doing more errands (more unnecessary "opportunity" charging), etc. Apparently far better to let the battery get down "more" and just recharge once.

Basically, avoid, when possible, "unnecessary" re-charge (top-off) cycles.

Because of this, folks have assumed that it MIGHT be better to only charge to the 80% level, unless one needs the "full-tank" range.

However, the occasional fill-to-100% MIGHT be needed to keep the cells balanced. But, we do not yet know. Apparently the manual refers to a "special" charge, which MIGHT be what is needed (occasionally?) for cell balancing. Yes, more things yet to learn about.