I get where you're coming from, but it really depends on how you drive. In winter on the highway, 270 miles is pretty good. But wait 'til summer in the city – you'll easily get over 300 miles.
Fuel efficiency is the same for gas and electric cars. If you're heavy on the gas, you'll burn more, whether it's gas or electricity. To maximize range, drive smoothly, and you'll see better mileage.
I agree with @Maricelle. I just switched from an i-Pace, and while the range is better overall, 300 miles still feels a bit optimistic right now. The Eletre's range estimate seems a bit off – it starts at 312 but drops faster than the actual miles driven. Hopefully, the upcoming software update will fix this.
Another thing that affects range is the regen braking. It's pretty passive, even on max. With the i-Pace, lifting your foot off the gas would make the electric motors work hard to recharge the battery. In the Eletre, I find myself using the brakes a lot more. I suspect I'm wasting energy heating up the brakes instead of recharging the battery. A more aggressive regen setting would be great!
