I am driving a loaner while waiting for my car to arrive at the dealership. This is only relevant, in that I am not changing tire pressures. So far I have driven about 400 miles of 65-75 mph highways, 100 miles of city, and 100 miles of 50 - 60 mph 'suburban' roads. These are roads I know well from my G2 Prius days, and my comments are best taken as comparison to my Prius. Do keep in mind that the CT has LRR 17 inch tires that have less than 2k miles wear, compared to 15 inch, 195 mm hydroedges with 70k miles on my Prius. Where the Prius in my hands was good for 65 mpg at 55 mph, the CT is somewhere around 58-60 mpg at 55 mph. Surprising to me, the CT mpg falls off pretty rapidly as speed goes over 60 mph. I was hoping I could drive faster than my G2 Prius and not take a big hit, but alas this is not the case. I presume the reason is related to aero drag. Easy city driving (many lights timed, no driver rage around me) is 50 - 60 mpg, compared to 65 - 75 mpg in the G2 when warm. One nice aspect of the CT (which I presume the G3 also has) is quick warm-up to EV gliding and ICE shut-off at stop. All told, the CT has a narrow window where it comes close to a G2 Prius in fuel economy, but it has other common modes where a 15-20% drop in MPG is seen. I expect that in my own car, when I downsize the tires to 205 mm width, inflate pressures, and grind off the new tire stickiness, I'll end up 5-10% below my G2 Prius overall.