speed still matters, driving at 70mph will be double the air drag than 50mph.
Speed also matters because going up a 25 mile long grade at 45mph takes 33 minutes, but taking that same grade at 60mph takes just 25 minutes. You’re fighting gravity for an extra 8 minutes at slower speed.
I understand what you are saying about how the work required to climb the hill is the same regardless of how fast you climb it. But that looks at the problem in a “spherical cow on a frictionless plain” kind of way. If it really was true that it’s all the same no matter how fast you go, then it should be possible to climb a grade at some ridiculously slow speed – say 1mph, and it would use the same amount of energy as climbing it at 50mph?! No…that’s not right. That super slow 1mph climb may consume the same amount of power to climb the elevation required ast the 50 mph climb, but the overall energy consumption of the entire system is going to be a lot higher for the 1mph climb.
That’s the crux of my question. And the article you linked about the Tesla Semi (and EV trucks in general) is more about “can they drive steep grades at the speed limit”, not “what is the optimal speed to climb a grade”. The computations done in the blog post are all assuming driving at the speed limit, not comparing the different consumption amounts for climbing at different speeds. It also completely hand-waves away the effects of wind resistance, which is the crux of what I’m asking.
Speed also matters because going up a 25 mile long grade at 45mph takes 33 minutes, but taking that same grade at 60mph takes just 25 minutes. You’re fighting gravity for an extra 8 minutes at slower speed.
I understand what you are saying about how the work required to climb the hill is the same regardless of how fast you climb it. But that looks at the problem in a “spherical cow on a frictionless plain” kind of way. If it really was true that it’s all the same no matter how fast you go, then it should be possible to climb a grade at some ridiculously slow speed – say 1mph, and it would use the same amount of energy as climbing it at 50mph?! No…that’s not right. That super slow 1mph climb may consume the same amount of power to climb the elevation required ast the 50 mph climb, but the overall energy consumption of the entire system is going to be a lot higher for the 1mph climb.
That’s the crux of my question. And the article you linked about the Tesla Semi (and EV trucks in general) is more about “can they drive steep grades at the speed limit”, not “what is the optimal speed to climb a grade”. The computations done in the blog post are all assuming driving at the speed limit, not comparing the different consumption amounts for climbing at different speeds. It also completely hand-waves away the effects of wind resistance, which is the crux of what I’m asking.