Putting some numbers on the factors that affect range

[Ulmo]

2. If you want to use gas less and save more money on a full battery-electric, look at the EPA range rating (not the higher marketing number. For example, Nissan often says the Leaf can go 100 miles. Tesla sometimes says the Model S can go over 300 miles. But the EPA ratings are 73 and 265). Now, subtract 1/3 to account for really bad weather or really high speeds (presumably you won’t do both at the same time). That leaves 49 miles for the Leaf, and 177 miles for the 85kWh Model S.

Those are numbers you can “count on” in your new car. Obviously you can do worse if you take it to the track or something, but as long as you aren’t trying to fail and really want to get somewhere, you will be able to go at least that far. You can take the car on any trip of that length without worrying or doing math; so just make sure your next Model S charging stop is never more than 177 miles away. Math is only required if you want to go farther than that without stopping to charge.

^^^ I think those paragraphs needs emphasizing. It should be on a placard sold with every EV.

In my Model S 60D (software limited 75) with my heating and driving habits and usual terrain, I get "slightly better than one mile per percent". That's about 80% of the "realistic" figure you quoted above.

I want to remember to come and look at this thread and similar threads next time I prepare for a long journey, to experiment with optimum driving speeds.

 

[ChadS]

Hi Ulmo. Do I understand you to say that you average just over 100 miles of range per full charge, or about 50% of EPA?

Of course that's possible; Car and Driver took a Prius around a test track and got 18mpg out of a 48mpg-rated car. It just is not common; in fact in over 150k of driving I have never seen a single trip anywhere near that bad. (Our long-term average is about 10% under EPA). It would be interesting to learn more about your typical driving conditions if you are willing to share.

Perhaps you take really short trips in cold weather, so the initial battery/cabin warming is having an oversized effect on the numbers. I don't even check the numbers on really short trips for that reason (well, that plus the fact that with a really short trip I am not worried about range), so it's entirely possible I have taken a short 50%-of-EPA trip, even though I don't average anywhere near that.

 

[majcina]

I'm guessing @Ulmo drives uphill both ways in snow.

 

[MocosMan]

Cheapest way to increase range is to inflate the tires a little higher than recommended.

From the 'mythbuster' test:
Recommended pressure: 35 psi
tyres at 10psi = 3.7% increase in consumption
tyres at 30psi = 1.2% increase in consumption
tyres at 40psi = 6.2% decrease in consumption
tyres at 60psi = 7.6% decrease in consumption

According to many people that have done this for years reported that their thread wear on the tires is very even, so no worries about uneven tire wear.

Tire wear may be even - but surface area of contact with the road is lowered. i.e. overinflation can cause accidents - be careful here.

 

[AWDtsla]

Tire wear may be even - but surface area of contact with the road is lowered. i.e. overinflation can cause accidents - be careful here.

Treating the tires like an infinite traction machine causes accidents. You should be able to successfully drive despite varying surface friction.

 

[FlyF4]

Gee, really informative post. Thanks for the good sleep (falling asleep as I consumed the data)
I was a little confused at first when looking at the numerical plus and minus numbers. Wasn't sure if you were talking about + mileage or + more energy used. But wasn't hard to understand when thinking about it.

 

[jerry33]

Treating the tires like an infinite traction machine causes accidents. You should be able to successfully drive despite varying surface friction.

Note that the more slippery surface conditions are often helped by increased pressure. Lower pressure gets you better traction on high friction surfaces--where it's least needed.

 

[FlyF4]

"Note that the more slippery surface conditions are often helped by increased pressure."
Really? I never thought about it until now, but it seems that it would be the opposite... lower pressure = more tire touching the road = better traction?

 

[MocosMan]

What FlyF4 said

 

[AWDtsla]

"Note that the more slippery surface conditions are often helped by increased pressure."
Really? I never thought about it until now, but it seems that it would be the opposite... lower pressure = more tire touching the road = better traction?

Depends on the surface. Some work better with lower area, meaning more pressure. Rally races prefer thinner tires, for example. In general the wider a snow tire, the worse it is.

 

[FlatSix911]

Keep in mind that proper inflation will maximize tire grip

 

[Ulmo]

Hi Ulmo. Do I understand you to say that you average just over 100 miles of range per full charge, or about 50% of EPA?

In Winter, I did for some trips. Longer was worse due to soaking footwell with cold air. TeslaFi:

I'm guessing @Ulmo drives uphill both ways in snow.

Only 3 times. Almost 100 times in rain. Uphill both ways? Of course! And back down again! Just the regular stuff: 17, 152, 580, Grapevine, Sierra Nevadas, etc. Just got back from Tahoe (got some beautiful pictures). Just came again to Central Valley.

I think most of it is just winter temperature taking more energy, and a bit of the old wanting to stay awake and not die of boredom adding air resistance and acceleration. The mountains do add another angle to it.

I keep thinking I've gotten better at handling my range distance, but I think a large part of that is illusory, because it's getting warmer and it just goes further in summer.

 

[AWDtsla]

Keep in mind that proper inflation will maximize tire grip

View attachment 221234

Radial tires don't really do really that, thanks to the radial steel belts. Except for extreme underinflation.

 

[meomyo]

what is proper psi in summer on tesla? 45psi? when driving this fluctuates sometimes 3-4 psi depending on heat and elevation for me. I see them going up and down alot between 45-50psi- should i lower the psi?

 

[Babaron]

From what I understand, the recommended pressures are cold pressures, around 68-72 degrees F. Those are expected to vary somewhat with weather and driving conditions while in use. But they shouldn’t be adjusted unless in extreme hot or cold weather or severe driving, like on the track.

 

[CaryRx]

Wow, I actually get some pretty good Wh/Mile figures, especially compared to Ulmo!! But, I'm in California, where we drive downhill both ways.... LOL

 

[MSLR]

Hi im new to electric cars and have a new long range model s thats says does 379miles on full battery i know you're not supposed to charge to 100% which means in the real world you really wont be doing that mileage

Last night I had a range of 270miles showing i drove 130miles which should leave me with 140miles i actually had 65miles left after my journey. Yes i had climate control on but surely it shouldn't make that much difference! Also the miles were done on the motorway is this normal? If not is there anyway i can fix this via the settings?

The car is on version 10

many thanks guys

 

[BridgeMojo]

Hi im new to electric cars and have a new long range model s thats says does 379miles on full battery i know you're not supposed to charge to 100% which means in the real world you really wont be doing that mileage

Last night I had a range of 270miles showing i drove 130miles which should leave me with 140miles i actually had 65miles left after my journey. Yes i had climate control on but surely it shouldn't make that much difference! Also the miles were done on the motorway is this normal? If not is there anyway i can fix this via the settings?

Congrats on the new Model S! Isn't it a blast?

First point: YES, you can charge to 100%. I do that with mine often. When I do, I don't leave it there for days or weeks, but start off on my trip. That said, if I actually have a trip planned that might need 500 miles in a day, I've discovered that there's no point in charging to 100%. All you need is enough to get to a mid-trip charge point, or evening charge station.

Second point: The miles remaining is based on a standard number of watt-hours per mile. On my car it's about 295, which gives me about 3 miles per kWh.

If your "miles remaining" is significantly lower than expected, you might want to take a look at the energy consumption rate. It's affected by driving speed, altitude changes, acceleration demands, wind direction, and things like that.

The "trip meter" is really useful for seeing the average wH/mile spent for a given trip. Next time you take the same route, reset one of your trip meters, and look at the average watt-hours/mile spent on the trip.

I've switched my own SoC "state of charge" display to read battery percentage rather than miles remaining. With a 100 kWh battery, the percentage is about the same as kWh remaining.

Mojo

 

[antdun]

Hi im new to electric cars and have a new long range model s thats says does 379miles on full battery i know you're not supposed to charge to 100% which means in the real world you really wont be doing that mileage

I recommend either using an API connector like TeslaFi or perhaps just reset one of the trip-o-meters and monitor the energy consumption while you drive to see how it's trending as your conditions vary, or as your driving varies (speed is the largest factor). That's what I've done and become quite comfortable with what to expect depending on what's going on. Regarding charging to 100% the biggest factor of battery longevity is heat and time at 100%. I always set the car to finish charging when I'm scheduled to depart. If you don't need the range then just go to 90%, but you shouldn't think of 100% as completely off limits, but ensure you drive soon when it's done charging.

 

[scottf200]

TeslaFI added 'avg range' and 'avg temp' to the 'your software updates' (Fleet menu option) area. Example from my son's car:
https://i.imgur.com/C6q3e4V.jpg