Sharing MYP towing range data w/ high loads

In a thread about towing in the MY subreddit, a couple people asked about range. This led me to writing a post w/ my experience towing boats, and I thought I'd share it here in case anyone was interested. The MY's tow limit is 3500 lbs, and both of these were close to that (photos at end). My car is a '20 MYP non-PUP (i.e. it has 19" Gemini wheels w/ OEM tires).

I've had two good distance drives towing two different boats. One weighs 3160 lbs with its trailer. The other hasn't been weighed, but we estimate it is probably right around 3500 lbs with trailer, maybe more like 3700. Both boats are significantly taller & wider than the car, so going above 55mph causes a significant range hit.

When I bought the lighter boat, the drive home involved four legs, three of which were for charging purposes. The first leg was short b/c I was already down to 27% charge when I picked up the boat. The 2nd leg was short b/c I wanted a super-accessible charger that didn't require getting off the highway, the best option was when I still had 57% battery. The last two legs were on a single charge, I just stopped to weigh the boat & trailer at a truck stop. The latter of those two was non-interstate slower highways and rural roads, so keeping speed down was easy - but I was also cutting it close on charge, I got home w/ 8%. There was another supercharger available, but it would have been about 10 miles out of the way, and the range estimating was proving to be pretty accurate, so I didn't bother.

Here are the stats for this trip:

• 25 mi, 580 Wh/mi, 40.8% efficiency, 49mph avg, 67mph max, elev +/-: +368/-371'
• 28 mi, 652 Wh/mi, 35.8% efficiency, 53mph avg, 66mph max, elev +/-: +535/-512'
• 57 miles, 725 Wh/mi, 32.3% efficiency, 58mph avg, 76mph max, elev +/-: +2197/-1768'
• 24 miles, 487 Wh/mi, 48% efficiency, 40mph avg, 60mph max, elev +/-: ??? (bogus data, 80k' +/-)
  • Note: there was 4 miles of fiddling around between the last two drives that I'm not bothering to report. I started the 3rd drive at 90%, and finished the 2nd one at 8%. The missing 10% is in those in-between drives.

Note: The trailer had improper car tires rather than trailer tires, not rated for the load they were carrying. They were also wider than trailer tires. I had them inflated at 45psi, which is high for the tire, but lower than what a trailer tire would have allowed.

I had one drive with the heavier boat:

• 46 mi, 622 Wh/mi, 37.6% efficiency, 48mph avg, 69mph max, elev +/-: +916,-968'

This was with proper trailer tires. I am 95% certain that I had deliberately inflated them towards the high end of their rated pressure range.

 

[avramd]

I haven't towed anything quite the heavy with my Model Y, but the Y feels way more peppy then the C70 ever did, and still is insanely responsive to the accelerator even with a trailer on the back and 2000 pounds of compost on it. It also seems to be way way less then a 50% range loss, although honestly I didn't tow the compost very far (like 20 miles).

Weight is not a big factor in range, especially with an EV. It affects handling, acceleration and deceleration. The latter two of those are made up for quite a bit by regenerative breaking. Aerodynamics are the biggest factor in range impact. If you made a 50 lb carbon fiber shell that was the same size & shape as my boat, you'd probably only get about 10% more range than with my actual boat. Conversely, if you towed a 3,500 lb solid gold brick that fit neatly within the wind shadow of the car itself, as long as it was on good bearings and high pressure tires, you'd probably only use 10% range.

Of course I should comment that the effect of weight is inversely proportional to the power of the motor in the first place. IOW, the bigger a motor you have to begin with, the farther it still is from its limits when towing something heavy. So yeah, our MY's have much more reserve power than most ICE vehicles, and that's a big win for towing.