Tray Burge
TJ Addict
Your axles are geared to the factory ratio which is only correct for the factory size tires. The 33" tires reduced the engine rpms at any given speed so its not developing as much power as it did with the factory size tires. Your rpms are so low from the factory axle gearing with the 33" tires your engine is lugging on the highway.
Your factory axles were geared to a 3.73 ratio and you need to regear them to 5.13 to get the engine rpms back up enough for the 33's. 5.13 will give appropriate highway cruising rpms and restore its drivability where it will again be fun to drive. Don't let some shop yahoo talk you out of 5.13, he doesn't know your 42RLE automatic transmission ratios and why 5.13 is the correct ratio for a TJ with your transmission and 33"tires.
Do what Jerry said. I have the same tires with a 4 banger and it's made the world of difference. Not only do I have more power in the upper range, it's also present in the lower range of that particular gear too.