First road trip

dbsb3233

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Thanks for the write-up.

I think if any of us ever find ourself in a situation where we are a little bit below the range necessary to reach the destination and there is absolutely no nearby charging possible, the best bet would likely be to exit the freeway and use surface streets to drive 25mph or slower if possible and slowly move towards the destination/charger, with maybe a plan to pull into a business where you can use the L1 mobile charger if you are really up against 0 miles of range.

I think this would apply to any EV and think slower maximizes range on EVs if I understand how they work correctly - like if someone did an experiment where they were just moving at 5-10mph, could massively beat EPA range on any EV.
I've wondered what the "most optimum" speed actually is. I was guessing more like 45 MPH, but I really don't know. But I suspect the motors have a mid-range area where they have their most optimum miles/kWh result. Plus, the car is using some energy just being on, which means time is energy. So there's a little saved from that by getting there quicker.

Of course, practicality usually overrides that. Rarely is there a road available where we can just go a constant 45 MPH without lots of stops/starts. Even though regen is pretty efficient, it's not 100% efficient. And acceleration isn't as efficient as just maintaining speed. Meaning stop-start driving is less efficient than continuous driving of the same average speed.

While it sucks to have to do it (and sucks for others on the road), it might be better stay on the highway and just to slow to a constant 55 MPH or something rather than get off and do a ton of start/stop. That would be an interesting comparison to test out.
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timbop

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I've wondered what the "most optimum" speed actually is. I was guessing more like 45 MPH, but I really don't know. But I suspect the motors have a mid-range area where they have their most optimum miles/kWh result. Plus, the car is using some energy just being on, which means time is energy. So there's a little saved from that by getting there quicker.

Of course, practicality usually overrides that. Rarely is there a road available where we can just go a constant 45 MPH without lots of stops/starts. Even though regen is pretty efficient, it's not 100% efficient. And acceleration isn't as efficient as just maintaining speed. Meaning stop-start driving is less efficient than continuous driving of the same average speed.

While it sucks to have to do it (and sucks for others on the road), it might be better stay on the highway and just to slow to a constant 55 MPH or something rather than get off and do a ton of start/stop. That would be an interesting comparison to test out.
I agree staying on the highway and slowing down is probably the best answer, as surface streets rarely parallel highways over long distances; you'd probably waste a lot more energy zigzagging. Since the bigger factor at faster speeds is aerodynamic drag, slowing down from 72 to 60 would probably increase efficiency from 2.8 mi/kwh to 3.5 (at least based on the 2000 miles of driving I've done).
 

ARK

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I've wondered what the "most optimum" speed actually is. I was guessing more like 45 MPH, but I really don't know. But I suspect the motors have a mid-range area where they have their most optimum miles/kWh result. Plus, the car is using some energy just being on, which means time is energy. So there's a little saved from that by getting there quicker.

Of course, practicality usually overrides that. Rarely is there a road available where we can just go a constant 45 MPH without lots of stops/starts. Even though regen is pretty efficient, it's not 100% efficient. And acceleration isn't as efficient as just maintaining speed. Meaning stop-start driving is less efficient than continuous driving of the same average speed.

While it sucks to have to do it (and sucks for others on the road), it might be better stay on the highway and just to slow to a constant 55 MPH or something rather than get off and do a ton of start/stop. That would be an interesting comparison to test out.
I thought around 45mph might be optimal for an ICE, but I tried looking this up just now and couldn’t find too much info on it for EVs. It’s sort of indirect, but Car & Driver says this:

“Our EV range test is done at a steady 75 mph, because highway driving is where range matters most. If you're looking to cover 500 or 1000 miles in a day, it necessarily has to be done at high speeds. There's just not enough hours in the day to do otherwise. Even the shortest-range EV can manage more than 7 hours of slogging through city traffic at an average speed of, say, 15 mph. Also, unlike a gas-powered vehicle, an EV's consumption increases dramatically as speeds rise. Of course, as with all cars, aerodynamic drag inflates with the square of speed, but EVs are particularly affected as all but the Porsche Taycan lack multiple gears. So, a higher vehicle speed means the electric motor is spinning at a faster and less-efficient point.” Link to C&D article.

@timbop raises a good point though, not all highways have a parallel boulevard or country road, especially if you are going over a mountain pass or the like.

That C&D article raises a good point about the Taycan though and its two gears. I wonder why more EVs don’t have at least two gears with one of them being a really tall gear that gives you terrible acceleration but is relatively efficient for highway cruising. Maybe it’s been a cost issue. Other testers have already shown how the Taycan really blows away its EPA range.
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