I have a 70D, currently charged at 75% showing 177mile range. This means at 100% charge, this would be 177/0.75 = 236 mile range. Shouldn't this be 250 miles? Is this the ideal vs. rated mile thing? Is rated mile calculated per my driving style? My mi/kwh is around 270, which I think is pretty good. Long story short, is that 250 mile advertised range impossible to acheive in normal circumstances?