I dont think you would get better since adding the extra weight. Id be interested if someone said they did though.

 

around the cuty it will be worse, but you're effectively giving yourself a taller gear ratio which will keep your highway rpm lower. and the added weight of the tire wont matter as much as city because it'll already be rolling. the stop and go will be rough though.

 

Your stock is can handle 33's no problem, I have 35's with the 3:31 gears.

 

I'm running 35" Goodyear Wrangler MT and have 3.73 gears. It runs fine, a little slow off line but once I'm rolling its all good.