this post was submitted on 06 Jan 2024
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Tesla Cybertruck gets less than 80% of advertised range in YouTuber’s test::A YouTuber took Tesla’s Cybertruck on a ride to see if it can actually hit its advertised 320-mile range, only to find out that its could only reach 79% of the target. When YouTuber Kyle Conn…

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[–] [email protected] 3 points 10 months ago (1 children)

The EPA highway test is 55mph or something around that. These real world tests are all 70mph+

The only way you do better or equal on a 70mph test is

  1. Advertise a smaller range than you actually have

  2. Gear the motor for high speed and have worse performance at lower speeds (EVs typically do better at low vs high, but you could make low even worse)

  3. Have a multi gear motor like Porsche and I think some Audi. Then you don't have to optimize the motor on 1 gear, but it substantially increases cost (but it's a porsche) and complexity and repair costs.

The EPA just needs to make a 70mph test part of the test cycle and make them advertise that.

[–] [email protected] 2 points 10 months ago (2 children)

The gearing in the Taycan/E-Tron GT aren't for efficiency, but for speed. Electric motors don't really lose efficiency as they spin faster, but they do start to lose the ability to move the car faster against the exponentially increasing wind resistance. This isn't an issue for most cars (they top out around 110mph), but for something like the Taycan it's important (tops out around 155mph).

The 70mph situation is more that manufacturers de-rate their cars. Both the Taycan and the Lyriq (a SUV brick) are well-known for demolishing their EPA ranges in 70mph cruising tests. Even the EV9 (the brickiest brick) exceeded the EPA range in this same test.

[–] [email protected] 2 points 10 months ago* (last edited 10 months ago)

Unrelated to my other reply - but I think it'd be interesting to see how much other manufactuers de-rate their cars, by having independent testers also run an EPA test just like they run real world tests.

I'd love to see them run reports saying XYZ car has an actual epa range of XYZ even though they report ABC

[–] [email protected] 1 points 10 months ago* (last edited 10 months ago)

This is right from energy.gov

https://www.energy.gov/eere/amo/articles/determining-electric-motor-load-and-efficiency

Most electric motors are designed to run at 50% to 100% of rated load. Maximum efficiency is usually near 75% of rated load. Thus, a 10 horsepower (hp) motor has an acceptable load range of 5 to 10 hp; peak efficiency is at 7.5 hp.

They also run more poorly below 50%.

To get a good city/highway range they would need to try and keep the motor above 50% for city, while also keeping it ~~under~~ around 75% for highway. How you move that gearing will impact range at higher speeds or lower speeds. Maybe it's not as much as I think, but it definitely comes into play, and the Taycans geared motor helps some amount.

Tesla has definitely honed their motors to maximize the EPA range vs higher speeds in addition they aren't de-rating like some other manufactures do.