I got really good mileage once. The charging station I chose was not working and I drove to a nearby station doing maybe 25 on city streets long after midnight. Instead of arriving with 1% I arrived with 4%.
Probably would have gotten better mileage if I ran red lights and made stop signs optional.
Pepe's Towing, the heavy towing company in LA with a very popular YouTube channel, has two questions for drivers whose trucks need to be recovered or uprighted - "What's your cargo?", and "How much does it weigh?". (Pepe's comments that most drivers who roll over a truck cannot answer either question, which has a lot to do with why they rolled over.)
Since cargo is enclosed on most semis, assuming identical trailers load doesn't really matter. Aging Wheels has a video on testing that in the silverado ev and got about 5%: https://www.youtu.be/UmKf8smvGsA
I friend told me a story of when he drove trucks in a previous life.
Once he had to drive a water tanker truck and someone ran a red light in front of him as he entered an intersection. He slammed on the brakes, but his water load sloshed. It would skid his truck forward into the intersection with each slosh. He avoided the accident, but just barely.
That is just plain wrong. There is a reason why all EV companies, including Tesla obsess over energy density, and it’s because load is one of the biggest factors that affects range.
Forget EVs, load also affects range for traditional Semis. Do you seriously think an empty semi and one with a shipping container on the tow, would both have the same range?
> That is just plain wrong. There is a reason why all EV companies, including Tesla obsess over energy density, and it’s because load is one of the biggest factors that affects range.
Energy density is energy per unit of volume. Every company obsesses over that because volume is the limiting factor for getting energy in a vehicle.
Energy specificity (energy by unit of weight) is only relevant to planes, no EV company gives much of a fuck about it. Would they like it if batteries were lighter? Absolutely. Would they take a heavier battery if it was denser? In a heartbeat.
> Forget EVs, load also affects range for traditional Semis.
There are major differences between a traditional prime mover and an electric one: electric motors don’t have the divergent torque/power curve of ICE, or the choked low end, and moving a load is kinetic energy which EVs can largely convert back into electricity instead of losing it entirely. So the inefficiencies related to getting the load moving largely go away.
Well arguing load isn’t a factor and the real limitation is the volume is still wrong. EVs aren’t infinite in size and real world constraints exist. At the end of the day, your semi cannot be 90% battery and ferry only a pallet of chips.
Total energy spent on moving an object by a distance is still proportional to the mass of the object. So if you’re absolutely spending more energy hauling 10000lbs vs 100lbs.
The only point where the cargo is relatively immaterial to the range is when it is a very small percentage of the actual weight of the vehicle. But that doesn’t mean the vehicle is efficient. It’s just that now you’re spending more energy hauling the battery itself than the cargo. Energy density matters in semis because companies want to spend less money hauling the battery itself than the cargo to make it viable.
> Total energy spent on moving an object by a distance is still proportional to the mass of the object.
It is not. The energy spent to change momentum is proportional to mass. For mass to affect momentum you need a second order effect linking it to increased system losses e.g. a heavier plane needs more lift, which requires higher speeds, higher angle of attack, larger lifting surfaces, …, all of which increase drag, which is the primary way planes lose energy.
> Rivian an electric car company admits that towing will reduce your range. There’s a reason for that.
Being a two-time Tesla owner for 8 years, at this point, there is no claim Tesla can possibly make that I would ever believe. Their (and Elon’s) track record on countless claims have been wildly misleading at best or completely false at worst.
Trucking seems like an industry where exaggerating the range will lead to contracts being cancelled and companies being sued. I'm assuming that a Tesla Semi can't just stop off at the nearest Supercharger.