# Issues with EPA rated range



## ashu4apollo (Sep 21, 2020)

I did a long drive on my SR driving at 223wh/mile with a range of 185 miles, while EPA rating says you get 220 miles driving at 219 wh/mile. Has anyone experienced a similar issue?


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## bwilson4web (Mar 4, 2019)

No. You have to set the cruise control to 62-63 mph on a standard day. You can't drive into a headwind nor temperature above 55F.

Bob Wilson


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## Feathermerchant (Sep 17, 2018)

You know how your range goes up in a gas car when you drive on the highway? Well it's the opposite for EV's. The faster you drive the less your range.
EPA is a mix of slow and fast driving. When you take a trip, it is mostly fast driving.


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## garsh (Apr 4, 2016)

ashu4apollo said:


> EPA rating says you get 220 miles driving at 219 wh/mile.


EPA isn't really saying that. It just gives you a number to compare to other vehicles. The number is derived from a particular testing regiment that all cars follow.

It comes close to what you can expect to get when driving around 55-60mph on a flat road on a warm day.
Here was my experience with real-world range:



garsh said:


> An additional useful fact I learned on the last leg of this trip. There was one especially-long leg that I was able to make due to the availability of destination charging at Cornell, and lucky placement of a supercharger at the end of my car's range. Real-world, 70 mph usable range of my Performance Model 3 with OEM 20" wheels & tires is going to be about 245 miles. This was in about 80° F weather. I started off with a full 100% charge (last I checked, that now equates to 302 miles showing on my car), and arrived at the supercharger with 5% charge. Interestingly, the car was predicting I would arrive with 5% battery from the very beginning of the trip, all of the way to the end - I was very impressed by that. Remember folks, the 310 mile advertised range applies at about 60 mph - driving faster reduces that range.
> 
> https://abetterrouteplanner.com/?plan_uuid=36290234-5b83-4cb5-bb0b-b906f381839a
> 
> View attachment 28106


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## Ed Woodrick (May 26, 2018)

Just slow down a little. Watch the energy graph and it becomes obvious. 

And it will drop a lot as the weather gets cold.


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## JasonF (Oct 26, 2018)

ashu4apollo said:


> I did a long drive on my SR driving at 223wh/mile with a range of 185 miles, while EPA rating says you get 220 miles driving at 219 wh/mile. Has anyone experienced a similar issue?


I see your profile says you're in Tampa. If you went driving during the past week, you probably encountered a lot of factors that could affect range:

- Extreme heat (close to 100 deg F) both causes the cabin air conditioning to work harder, and that combined with speed also causes the battery cooling to work as well.

- Extreme heat also causes both the rubber tires and blacktop to become more sticky, increasing the amount of friction that has to be overcome to move the car. Race drivers count on that to provide more stability, which is why they do "warm up laps" to get the tires up to temperature.

- Last week was littered with heavy thunderstorms, rain, and wind. Wind of course creates resistance, but so does heavy rain. And heavy rain on pavement causes the wheels to slip just a tiny bit, which adds up to a lot of lost energy.

The weather has the same effect on gasoline and diesel vehicles, but guess what? Nobody is watching their energy consumption that closely. Most people would just stop for fuel a little earlier, and not really pay attention to how much is being used.

The EPA estimates do not take weather interference into account.


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## Bigriver (Jan 26, 2018)

ashu4apollo said:


> I did a long drive on my SR driving at 223wh/mile with a range of 185 miles, while EPA rating says you get 220 miles driving at 219 wh/mile. Has anyone experienced a similar issue?


Welcome to the forum! My first reaction when I read your post was Wow, you got 185 miles out of a SR!!

Thanks for telling us your Wh/mile displayed in the car.... it sounds like you were driving pretty conservatively and other conditions must have been favorable. But did you really take the battery from 100% to 0%? And was this one straight drive with no idle periods, in which energy was used but does not show up in the Wh/mile?

I obsessively watch my Wh/mile and how many actual miles vs "rated miles" I consume. My experience base is a 2017 model X and a 2018 model 3 AWD. In the energy graph in the car, 333 Wh/mile and 250 Wh/mile, respectively, are indicated as the "rated" line, which would seem to be the break even point. But it is not. Attaching a plot I put together of all my drives in which I had used at least 50% of the battery. (Edit: oops, not 50% for this data set.... think this was based on drives of at least 50 miles. Encompasses range of conditions - outside temp, elevation change, speed.) To get the rated range (i.e., delta rated miles less than or equal to actual miles driven), I have to be around 315 Wh/mile or 230 Wh/mile in the X or 3, respectively. Also note that there is a good bit of variance from drive to drive. Those who know more about batteries than I do say that it is actually pretty hard to precisely track the energy in them.

So no reason for you to care about the specifics of the values from my cars which are different from yours, but I offer them as a way to thoroughly answer yes, to whether anyone experiences that the car doesn't go as far as you expected, even if you were near what you thought was the target Wh/mile.

One final note: to me, the really great thing in my graph below is that there are data points above the "break even" of 1. I sometimes get more miles out of the car than it is rated for (on a prorated basis for the percentage of the battery that I used.)


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