We seem to keep coming back to discussions about the Bolt EV's freeway efficiency, and I maintain that (based on my experiences) the Bolt EV's efficiency up to 75 mph is very similar to my first generation Volt. In a recent test of the Ampera-E, Bjorn Nyland had measured its 75 mph cruising efficiency at 2.9-3 mi/kWh, which is significantly lower than what I typically see. It turns out that the Ampera-E uses different tires, and that could account for some of the differences in efficiency.
Personally, I don't think it accounts for the ~15% difference in efficiency, but none of this is rigorous, scientific testing. Regardless, I just so happened to have a recent trip that allowed me to track my real-world efficiency by hoping on the freeway almost immediately (normally, I have a 20 to 30 mile drive first) and driving nearly 100% of the first leg at 70-75 mph freeway speeds.
Despite having brand new tires, the efficiency was still in line with what I typically see. After 84 miles of driving, I had an efficiency of 3.3 mi/kWh, including close to 5% of the energy being used for climate control. That very closely aligns with the ~3.5 mi/kWh I see at close to 70 F ambient temperatures without climate control usage.
Personally, I don't think it accounts for the ~15% difference in efficiency, but none of this is rigorous, scientific testing. Regardless, I just so happened to have a recent trip that allowed me to track my real-world efficiency by hoping on the freeway almost immediately (normally, I have a 20 to 30 mile drive first) and driving nearly 100% of the first leg at 70-75 mph freeway speeds.
Despite having brand new tires, the efficiency was still in line with what I typically see. After 84 miles of driving, I had an efficiency of 3.3 mi/kWh, including close to 5% of the energy being used for climate control. That very closely aligns with the ~3.5 mi/kWh I see at close to 70 F ambient temperatures without climate control usage.