Originally Posted by Redneck Truck

I'm aware of gearing and its potential effects on mileage; I'm talking about their actual effects in this case. It's been addressed extensively on Motorgeek - a taller 6th gear is something like a $1000 job and when asked, at least one person cited absolutely no change in fuel economy following the swap despite cruising at a much lower rpm, because the fuel economy effects of the drop in rpm and the increase in load canceled each other out. My Jeep and my Nissan truck both have tires 20-25% taller than stock, and the change in tire sizes alone did nothing for highway fuel economy and actually reduced city fuel economy once you converted from odometer miles to miles actually traveled.

As for tire weights and sizes, I couldn't find one tire in my usable range that weighed less than the tires on my car now (they are all at least a pound heavier, surprisingly enough), and the wheels I bought weigh more than the wheels on my car now. That said, I know lightweight alternatives may be available ceteris paribus, but in this case, it's really not an option.

Originally Posted by Redneck Truck

Dude, you're running 255 40 19? That's a very common tire size, and is what I wanted to run originally. What offset are your wheels? What did you have to do to clear the front suspension uprights? I was under the impression those would not clear the uprights or the steering arms at all. Please give me more information, as I have access to a really good set of yokohama 255 40 zr19s for $140 and would love to run them if I could. Thanks man!