I think the main reason for the increase is the tires wearing in.JSBSF wrote:2015 spark ev:
102 MPGe @ 1420 mile
(Caveat: when I got the car it had 64 miles with around 70 MPGe)
I usually see between 120 and 150 during a round trip. I get between 6 and 10 mi/ kWh to work, and 2 to 4 mi / kWh driving back home (I live on a hill). I've seen around 230 MPGe driving to work. I don't have a consistent driving habit, but practically always take the same route. Sometimes I use the heater, and it makes a big difference. I have been driving, so far, with the stock tires.
My numbers improved overall, after the first month or two. But I'm not sure why.
I would see a 5-10% reduction in fuel economy on my Prius with a new set of tires that would improve over ~5000 miles.