California is actually not a great example because their electricity rates are insanely high as well. A better example would be WA state where gas prices are very high but electricity rates are some of the cheapest in the country due to cheap hydro.
It sounds like you are trying to back-construct the reality you want, that low electricity prices lead to higher fleet efficiency, but that's flawed. You should look at the reality on the ground. Washington actually has double the rate of pick-up trucks compared to California, higher than the national average.