Consuming 40% more energy than estimated?

[jontallon]

I bought a used 2019 M3 LR this winter and took it on its first longer drive today. The car is in very good condition - there is nothing 'wrong' with it that I know of. But I was a bit surprised at the battery consumption. Basically I got about 170 miles of range on a car that was charged at 95% and said it would go 280-ish miles.

It wasn't a best case scenario - temp was about 35 degrees F., it was windy, it was all highway miles, mostly at 70 or 75mph. I also don't have wheel covers on the wheels. Tire pressure is fine though - 45psi all the way around.

Attached is a picture of the energy consumption charge from the car - basically you can see I was consuming more energy from start to finish through the whole trip. This was only one leg of the trip since I had to stop to charge, but the whole thing was this way.

Just wondering if this is 'normal' - does running near freezing really impact battery performance that much? I know it matters SOME, but I thought it got worse as you got colder, and it wasn't really terrible until you got down near zero - for some reason I didn't think 35 degrees F would matter much.

Or, any ideas on what else would be such a big drag?

Thanks! I love the car by the way - glad to be a part of the Tesla community!

 

[E90alex]

If you had a headwind and going 70-75mph that would definitely increase consumption. What brand/model of tires are on it?

Also if it was near freezing outside then the heater would have been running heavily to warm the cabin.

 

[GtiMart]

The rating is based on EPA which runs at 55mph or less, no heat etc. The single biggest thing that will affect consumption is going fast. 20mph over the epa test is significant. Heating adds to that. I'm not surprised by your result.
Was the road wet? That also augments resistance to rolling.

 

[KenC]

I bought a used 2019 M3 LR this winter and took it on its first longer drive today. The car is in very good condition - there is nothing 'wrong' with it that I know of. But I was a bit surprised at the battery consumption. Basically I got about 170 miles of range on a car that was charged at 95% and said it would go 280-ish miles.

It wasn't a best case scenario - temp was about 35 degrees F., it was windy, it was all highway miles, mostly at 70 or 75mph. I also don't have wheel covers on the wheels. Tire pressure is fine though - 45psi all the way around.

Attached is a picture of the energy consumption charge from the car - basically you can see I was consuming more energy from start to finish through the whole trip. This was only one leg of the trip since I had to stop to charge, but the whole thing was this way.

Just wondering if this is 'normal' - does running near freezing really impact battery performance that much? I know it matters SOME, but I thought it got worse as you got colder, and it wasn't really terrible until you got down near zero - for some reason I didn't think 35 degrees F would matter much.

Or, any ideas on what else would be such a big drag?

Thanks! I love the car by the way - glad to be a part of the Tesla community!

Wow, Wisconsin must be flat as a pancake.

As for your consumption, can you show us your consumption screen? It looks excessive to me. I would typically expect ~20% more consumption than whatever your norm is for that speed, solely due to temps.

Were you navigating to a supercharger, so pre-conditioning the battery? Can't think of anything else.

 

[jontallon]

Thanks guys for the guidance. KenC - yeah - the drive was from Milwaukee down to Chicago, which is about as flat as it gets.

The tires are Goodyear Eagle LS2's, which is what the dealer put on the vehicle before I purchased it used. They aren't EV specific tires, but they do seem to be decent.

Attached is the consumption chart for a drive out to dinner, but this is NOT the drive reflected above - it looks like on a Tesla you can't go back in time and see the chart for a past drive once you charged some. So this is just a drive around the country to a local restaurant.

It makes sense I guess that the rating is based on 55mph, because the Tesla doesn't know where you are actually going to drive - so 280 miles at 55mph would be dramatically different than 280 miles at 75mph - maybe it's just that...

Anyway, thank you!

 

[ewoodrick]

I bought a used 2019 M3 LR this winter and took it on its first longer drive today. The car is in very good condition - there is nothing 'wrong' with it that I know of. But I was a bit surprised at the battery consumption. Basically I got about 170 miles of range on a car that was charged at 95% and said it would go 280-ish miles.

It wasn't a best case scenario - temp was about 35 degrees F., it was windy, it was all highway miles, mostly at 70 or 75mph. I also don't have wheel covers on the wheels. Tire pressure is fine though - 45psi all the way around.

Attached is a picture of the energy consumption charge from the car - basically you can see I was consuming more energy from start to finish through the whole trip. This was only one leg of the trip since I had to stop to charge, but the whole thing was this way.

Just wondering if this is 'normal' - does running near freezing really impact battery performance that much? I know it matters SOME, but I thought it got worse as you got colder, and it wasn't really terrible until you got down near zero - for some reason I didn't think 35 degrees F would matter much.

Or, any ideas on what else would be such a big drag?

Thanks! I love the car by the way - glad to be a part of the Tesla community!

Did you read the text in the lower right of the picture?

Pretty much the worse situation for range would be 32F, windy, and going 75 mph. Whoops, that's what you were doing. You can indeed expect around 30+% mileage loss in those situations.

Once the temperature gets into the 70s, your range will increase
For about every 5 mph above 60 mph, you can expect a 10% loss in range.
Wind and rain blowing against you can hammer your range. If you are travelling out on the planes, you need to always make sure that you have plenty of range before the next charge.

Aerodynamics plays a large part in the range of a Tesla. It's an exponential increase, so it increases significantly with speed.

As for tire pressure, did you measure with the tires cold (more specifically room temp) or with the hot. The 42 psi r42-psindation, as all tire pressures are with the tires cold. Tire pressure will increase significantly after the wheels have been used.

Slowing down will definitely increase your range. when you are out on a flat road, watch the energy graph - consumption and go one speed for 5-15 minute and then go another speed, Look at the difference in the Wh/mi. You may be surprised

 

[cwerdna]

The rating is based on EPA which runs at 55mph or less, no heat etc. The single biggest thing that will affect consumption is going fast. 20mph over the epa test is significant. Heating adds to that. I'm not surprised by your result.
Was the road wet? That also augments resistance to rolling.

The EPA test is not run at 55 mph.

Please see pointers at Car battery: 340 miles. I drove 280. Came home with 5 miles left? for more info on the EPA tests. The highest average speed of any of their test cycles is 48.4 mph. In the "high speed" test cycle, they do reach 80 mph at max but the average speed of that cycle is only 48.4 mph. The other test cycles have average speeds of 48.3 mph or 21.2 mph.

I do agree with the rest of what you said.

 

[3sr+buyer]

I bought a used 2019 M3 LR this winter and took it on its first longer drive today. The car is in very good condition - there is nothing 'wrong' with it that I know of. But I was a bit surprised at the battery consumption. Basically I got about 170 miles of range on a car that was charged at 95% and said it would go 280-ish miles.

It wasn't a best case scenario - temp was about 35 degrees F., it was windy, it was all highway miles, mostly at 70 or 75mph. I also don't have wheel covers on the wheels. Tire pressure is fine though - 45psi all the way around.

Using the heater consumes significant energy, particular with an older car with a resistive heater (versus newer car with heat pump / reverse AC). Your image indicates that the car consumed "7.5 [rated] miles" for climate (heater) during your drive.

If you drive into headwinds or cross winds, expect energy consumption to increase.

If you drive significantly faster than 65mph, expect energy consumption to be higher than rated.

Removing the aero wheel covers increases consumption by a few percent at highway speeds.

 

[3sr+buyer]

The tires are Goodyear Eagle LS2's, which is what the dealer put on the vehicle before I purchased it used. They aren't EV specific tires, but they do seem to be decent.

According to https://www.tirerack.com/tires/Spec.jsp?tireMake=Goodyear&tireModel=Eagle+LS-2&isSEO=true , several sizes of the Goodyear Eagle LS-2 are OEM-special tires (Subaru, GM, Porsche, Audi), which means that those sizes are probably low rolling resistance. It could be that the entire model line in all sizes is low rolling resistance, or just the specific sizes used by OEMs. The sizes marked as OEM-specials do not include 235/45/18 (interestingly, there are two variants of that size).

 

[3sr+buyer]

The EPA test is not run at 55 mph.

Please see pointers at Car battery: 340 miles. I drove 280. Came home with 5 miles left? for more info on the EPA tests. The highest average speed of any of their test cycles is 48.4 mph. In the "high speed" test cycle, they do reach 80 mph at max but the average speed of that cycle is only 48.4 mph. The other test cycles have average speeds of 48.3 mph or 21.2 mph.

I do agree with the rest of what you said.

But note that the window sticker or fueleconomy.gov numbers have a substantial derating factor applied to the test results. Numbers used for CAFE do not, however.

From 1984-2007, the derating factor was -10% for city and -22% for highway. Starting in 2008, additional derating was done if the two cycle test was used (fueleconomy.gov now shows the additionally derated numbers for pre-2008 vehicles, but can also show the original window sticker numbers).

For example, Compare Original and New Fuel Economy Estimates shows that the 2004 Toyota Prius had original window sticker numbers of 60/51 (with the -10% city / -22% highway derating then used), but has ratings of 48/45 by current methodology. The actual test results used for CAFE were something like 66/65.

 

[cwerdna]

But note that the window sticker or fueleconomy.gov numbers have a substantial derating factor applied to the test results. Numbers used for CAFE do not, however.

Sure but Detailed Test Information also points to https://www.fueleconomy.gov/feg/pdfs/EPA test procedure for EVs-PHEVs-11-14-2017.pdf.

Yes, I'm aware of what you're referring to for ICEVs in terms of mpg values for CAFE purposes vs. what's on the Monroney sticker although I will admit I don't recall the percentages off the top of my head. And, yup, I recall the MY 2008 changes too.

 

[DuncanM]

I bought a used 2019 M3 LR this winter and took it on its first longer drive today. The car is in very good condition - there is nothing 'wrong' with it that I know of. But I was a bit surprised at the battery consumption. Basically I got about 170 miles of range on a car that was charged at 95% and said it would go 280-ish miles.

It wasn't a best case scenario - temp was about 35 degrees F., it was windy, it was all highway miles, mostly at 70 or 75mph. I also don't have wheel covers on the wheels. Tire pressure is fine though - 45psi all the way around.

Attached is a picture of the energy consumption charge from the car - basically you can see I was consuming more energy from start to finish through the whole trip. This was only one leg of the trip since I had to stop to charge, but the whole thing was this way.

Just wondering if this is 'normal' - does running near freezing really impact battery performance that much? I know it matters SOME, but I thought it got worse as you got colder, and it wasn't really terrible until you got down near zero - for some reason I didn't think 35 degrees F would matter much.

Or, any ideas on what else would be such a big drag?

Thanks! I love the car by the way - glad to be a part of the Tesla community!

I've found that driving at ~60 mph in mid 50sF will result in a range very nearly equal to the EPA figures:

A road trip/range test

Road tripping in my LFP TM3. (Feb 25 2023) My wife and I needed to do a grocery run and we combined it with a drive through Columbus NM. We drove from our home to Hwy 80 and thence to Hwy 9 and Columbus NM, where we turned north to arrive in Deming. After dinner we shopped at the local giant...

teslamotorsclub.com

Driving at ~82 mph in mid 40s F consumed 33% battery to travel 63 miles. 18in OEM tires with aero wheel covers.

 

[AlanSubie4Life]

I bought a used 2019 M3 LR this winter and took it on its first longer drive today. The car is in very good condition - there is nothing 'wrong' with it that I know of. But I was a bit surprised at the battery consumption. Basically I got about 170 miles of range on a car that was charged at 95% and said it would go 280-ish miles.

It wasn't a best case scenario - temp was about 35 degrees F., it was windy, it was all highway miles, mostly at 70 or 75mph. I also don't have wheel covers on the wheels. Tire pressure is fine though - 45psi all the way around.

Attached is a picture of the energy consumption charge from the car - basically you can see I was consuming more energy from start to finish through the whole trip. This was only one leg of the trip since I had to stop to charge, but the whole thing was this way.

Just wondering if this is 'normal' - does running near freezing really impact battery performance that much? I know it matters SOME, but I thought it got worse as you got colder, and it wasn't really terrible until you got down near zero - for some reason I didn't think 35 degrees F would matter much.

Or, any ideas on what else would be such a big drag?

Thanks! I love the car by the way - glad to be a part of the Tesla community!

A good rule of thumb in an LR is to expect no more than 200 miles on a charge segment in best-case conditions. I am not saying you cannot do better. Especially in a LR RWD or with aeros you can really push it. But 200 is a good rule of thumb.

One thing missing that you should be aware of is the trip meter. As you have discovered it does not keep this data so you have to track it if you care.

This is The Way. To figuring out nearly exactly how many rated miles you will use for a given efficiency result.

It doesn’t answer the “why” question of course but that seems pretty clear here.

Assuming your LR (AWD?) is charging to 280miles at 95%…and you got 170 miles out of it (say to 5%).

(280rmi/0.95)*0.9*234Wh/rmi*0.99/170mi = 361Wh/mi.

That’s definitely high but not necessarily a surprise given the conditions. Also obviously I am making big assumptions in the formula above which can be easily modified. I definitely would expect in excess of 310Wh/mi for this case.

But you get the idea for the fairly trivial math and can plug in your own numbers into above - basically always works except in very unusual cases (BMS the bed). Very deterministic.

The EPA 20F cold temp test does extract significantly less from the pack FWIW. (You can easily look at the detailed EPA doc results at iaspub.) But that may not be directly applicable to highway speed results because the draw will be higher and that could warm things up and help.

 

[Big Dog]

The rating is based on EPA which runs at 55mph or less, no heat etc. The single biggest thing that will affect consumption is going fast. 20mph over the epa test is significant. Heating adds to that. I'm not surprised by your result.
Was the road wet? That also augments resistance to rolling.

And warm-ish weather, say 70 degrees for the testing; feds don't test in freezing weather. in addition to your heater using extra juice, batteries aren't as efficient at 35 degrees as they are at 75 degrees. (Just basic battery chemistry.)

Try that run in warmer weather and see how it goes.

btw: turn the heater down a few degrees and your seat warmer up. (Seat warmers are more efficient than cabin heater.)

 

[AlanSubie4Life]

feds don't test in freezing weather.

Yes they do. 20F cycle. The result of that test does slightly affect the overall result, otherwise a heat pump would be nearly pointless in terms of improving the rating. Also it is Telsa testing in general, not the feds.

 

[GregBallantyne]

To the OP.... 75 mph with a fair amount of wind will reduce your range, as others have said. Running a lot of heat will as well. Generally, much depends on a few habits while driving. Of course, a windy day isn't a habitual sort of thing, but getting used to running heat and such in colder weather may take some habit adjustment to maximize your efficiency.
My lifetime wh/m average, over 4.5 years and almost 53k miles is 239, just a touch above the EPA basis. I don't go slow on the highway, I just probably average a lower percentage highway driving to total miles driven than many. Perhaps my driving more closely aligns with the driving mix used for that testing. My most significant cold weather reductions get to around an 18%-20% reduction from usual, and my car predates the heat pump. Not sure about yours. Some additional habits are pre-warming the car and battery while still connected to power and that sort of thing. There are also some general driving habits that can have a noticeable effect, unrelated to temperature. I would suggest keeping your live trip data showing in the small screen box, paying attention to it, and letting the data lead you to them. Wind and terrain are different. Your efficiency on that ride perhaps could have been improved on with the right tweaks, but it simply could have been conditions coupled with speeds. Not out of the question. BTW, I've never been able to find a noticeable difference with or without the aero covers. I took them off some years ago, and never put them back on.

 

[mjwojtukiewicz]

Attached is from my car 2019M3 SRP. 50/50 highway streets. I don't exceed 55 mph, I gradually accelerate and I coast to a red light. Temperature is 55F today, been 40-60 since last charge a few days ago. You CAN get 5-6 miles per kwh if you don't drive like a maniac.

 

[GBMaryland]

If you have a performance model, make sure you were and chill mode. I’m sure someone mentioned this, but that’s another factor.

Without a doubt, they don’t perform as well and very cold weather. I’ve always found the bigger issue to be that they don’t charge quickly unless they were reconditioned for a very long time, and then they still tend not to charge rather quickly when you connect to a supercharger in very cold weather.

 

[Rocky_H]

it was windy, it was all highway miles, mostly at 70 or 75mph.

When you say "it was windy", the car could be seeing that as 95 mph worth of wind resistance, rather than 75 mph. That's just what a headwind can do.

 

[AlanSubie4Life]

make sure you were and chill mode.

This makes no difference of course. Why would it?