impact of extra occupant weight on range

Owners, I am considering purchasing a LEAF next month. I would have to make occasional ~70 mile trips with three occupants plus a dog, mostly freeway @ ~60 mph. Total occupant weight (including me) about 400 pounds.

Any observations of the difference in usable range between single driver vs driver with occupants at freeway speeds? Thanks.

The laws of physics dictate that it will have an impact, but I haven't noticed any significant change in practice. Then again, I haven't conducted any scientific test for it either.

On completely flat terrain at a constant speed, extra mass will not affect your range. Driving uphill, yes, your range will be affected somewhat by extra weight. On the other hand, even if there are ups and downs, having an additional passenger should have little impact on your range if your trip starts and ends at the same elevation. At freeway speeds, wind resistance is typically the biggest factor.

BTW, I recently climbed about 5000 feet with a full car: http://www.mynissanleaf.com/viewtopic.php?f=31&t=3512&p=91465&hilit=6600#p91465

i concur with the above. freeway has less acceleration. additional weight makes the biggest difference when accelerating and that happens at a much greater rate in town due to stop and go (on the freeway at CONSTANT speed, you are still accelerating to maintain speed due to overcome the effects of air friction and gravity)

It does not exactly apply here but the rule of thumb on a conversion was 100 wH/mi for every 1000lbs of weight. So a 2000lb car got 200wH/mi and a 3000lb car would get about 300wH/mi. Using this to figure out the impact of a passenger says that a 200lb passenger would raise your consumption by 20wH/mile. We all know that the leaf gets an epa rating of 73 miles / 24kWh which is about 328wh/mi for a 3400lb car, so it still falls close to this estimate, though I'm getting closer to 250wH/mile on my leaf given my past EV driving experience.

Anyhow, the short answer is that a ballpark figure would be an additional 10wH/mile for every 100lbs of passenger weight.

On a side note, if you can pull 100lbs off of the car you should gain 10wH/mile which is a 10/328 = 3% improvement. I wish Nissan would have paid more attention to weight, and the car could have easily been 500 lbs lighter and would likely have a 15% better range. I can't seem to find any easy way to remove more than a 100lbs or so.

And to continue with the theme above, the estimate above is for average consumption (EPA mixed driving). Effect of weight is less on freeway than in the city due to stopping and starting. It also has more of an effect on hilly terrain than on flat.

have to dispute the statement that Nissan could have "easily reduced the weight 500 lbs".

weight had to be the topmost priority right after range. i find it difficult to believe you know more than the people who designed the car.

DaveinOlyWA said:

weight had to be the topmost priority right after range.

Click to expand...

I would have thought the same thing, but for some reason, Nissan seems to have chosen to use standard parts on this car (presumably to reduce cost), and that kept the weight up. If they had actually focused on weight, the car should not have been over 3000lbs.

I'm fairly certain that if the Leaf is determined to be a success, the next generation will have more purpose built parts and the weight will come down.

standard parts on what? the frame...not a lot of options there.

body panels? ABS is significantly more expensive. Aluminum a decent compromise on a cost standpoint

elaborate please

Every component in the entire car. A few grams from every one will have a significant impact. Wheels alone could save 40lbs as noted by Skywagon. Seats are very heavy, lots of excess castings under the hood, liquid heating, etc. You name the part, I can see a way of saving a few grams.

I don't expect that I'll convince you of anything, so I'm going to just stop here. Believe what you like.

palmermd said:

Every component in the entire car. A few grams from every one will have a significant impact. Wheels alone could save 40lbs as noted by Skywagon. Seats are very heavy, lots of excess castings under the hood, liquid heating, etc. You name the part, I can see a way of saving a few grams.

I don't expect that I'll convince you of anything, so I'm going to just stop here. Believe what you like.

Click to expand...

Based on what I have seen they could easily dump 200 at no cost and likely up to 300, there are MANY parts with extra bulk that in no way impact the strength. Some parts in the car that hold basic items look like steel from a truck. If you look at cars like the Yaris they made every part with weight in mind, the front bumper looks too thin and is very low weight but if you try to drill it you realize it's boron steel.

i am not saying you cant make the car lighter. i am saying you probably cant do it cheaply.

you are basically implying that Nissan Engineers did not look at the weight factor which is completely groundless. efficiency in an EV; one of the first things they look at is weight.

but they are not designing a $100,000 car. sure a Tesla is lighter. Carbon fiber does that. but they had the money to implement the design.

i fully expect the weight to go down, but not due to some watershed event in materials or an "ah ha" moment either. the weight will go down due to volumes of an established product that reduces cost and allows engineers to start shaving weight.

this is NORMAL. lets look at the efficiency of the Gen 1, 2 and 3 Prius. each car got bigger, faster AND MORE EFFICIENT.

success of the Gen 1 Leaf will insure the same progress

DaveinOlyWA said:

you are basically implying that Nissan Engineers did not look at the weight factor which is completely groundless. efficiency in an EV; one of the first things they look at is weight.
i fully expect the weight to go down, but not due to some watershed event in materials or an "ah ha" moment either.

Click to expand...

I never said nor implied that the Nissan engineers were ignorant, nor that the did not pay ANY attention to weight. I said they did not pay enough attention to it, and it resulted in a car that should be lighter.

DaveinOlyWA said:

the weight will go down due to volumes of an established product that reduces cost and allows engineers to start shaving weight.

this is NORMAL. lets look at the efficiency of the Gen 1, 2 and 3 Prius. each car got bigger, faster AND MORE EFFICIENT.

success of the Gen 1 Leaf will insure the same progress

Click to expand...

Now your just repeating what I said earlier.


I think we have the same view on this and you just created an argument over nothing. We both agree that the car could be lighter and will become lighter. I just wish it was lighter NOW.

ok, i can go with that

Clearly Nissan DID have weight in mind or they would not have opted for aluminum doors and hoods. They are not common parts and are not inexpensive.

palmermd said:

DaveinOlyWA said:

weight had to be the topmost priority right after range.

Click to expand...

I would have thought the same thing, but for some reason, Nissan seems to have chosen to use standard parts on this car (presumably to reduce cost), and that kept the weight up. If they had actually focused on weight, the car should not have been over 3000lbs.

Click to expand...