I just recently purchased a 2018 Volt, and I'm liking it so far except for one thing: EV efficiency at highways speeds.

I was a long time gen 1 Volt owner (2014), and I was able to get

**3 mi/kWh**(333 Wh/mi) driving at a constant speed at 80mph. With it's 10.1 kWh usable battery, I was able to get 29-30 miles of realistic range cruising at 80mph. This is with HVAC on Fan Only.

With gen 2, I was expecting that same kind of efficiency, but that isn't my experience so far. In the same route I usually take, cruising at 80mph, I'm only able to get ~32 miles of effective driving range. With 14.2 kWh usable in the battery, this comes out to only

**2.28 mi/kWh**(439 Wh/mi)! This is at similar ambient temps as with gen 1.

As a comparison, I did the same route again cruising at 75mph and I was able to get 36 miles of EV range. This comes out to

**2.55 mi/kWh**(392 Wh/mi). A tiny bit better, but still much less efficient than gen 1 Volt. I should also mention that in both range tests, I had the cruise control turn on with a set speed.

Any idea of what could be going on here? Did the switch from 1 electric motor to 2 motors negatively effect the efficiency? Or did GM tune the gen 2 Volt to be more efficient at lower speeds, thus sacrificing efficiency at high speeds? I'm really bummed out about this, as I was hoping to get at least 42 miles of realistic driving range at 80mph, which is what I would've gotten with the gen 1 Volt had it had a usable 14 kWh battery.