There's a Uniroyal that is actually quite a bit lighter and is only 29.9" tall instead of 30.4 or so. The Δ for the radius / axle will be 0.65" for most and 0.4" for this tire. Too bad it is a Uniroyal.
The mass of the tires is gonna hurt. I can't drive across the city at a time where I won't need brakes. Short drives on short sections of roads in cold weather... yahoo. BTW, I got even worse mileage with my Aerostar before this and I drove it very mildly in the winter - no snows, I had to.
Few people ever check their mileage except on long trips with summer gas. They end up thinking their overal mileage is way better than it is, especially in the winter. My wife's car and MetroMum's Corolla are proof. I finally realized this winter that axle bearings alone have a big impact on short drives.
The taller tires could help with cold rolling... a bit better gearing too although it puts my 4th 5th shift speed up from 62 KPH to 65 KPH. My speedo error is just less. All cars with analog speedo error on the side of no tickets
and shortens the warranty. Honda lost a class action suit for this a couple of years ago. Anyway, same deal here. If I am driving at 100 KPH, the speedometer says 103 KPH plus or minus 1 and is GPS and mile marker verified. Funny how the ODBII port is bang on right from the factory. Anyway, I'd go 3% in their favour to 1.5% in my favour with 30.4" tall tires, and just about neutral for the Uniroyals.