So far, so good! My new-to-me 2006 LS430 is averaging about 20 mpg in what I'd call "residential" driving and about 26 on the road. The best run across north Alabama at 60-65 mph yielded 29 mpg. Would like to find some stock 17" wheels to replace the chrome 18" stock wheels I now have. From what I've read, I'd surmise, that 17" wheels & tires would yield a softer ride and better gas mileage. :)