Regear Options for an auto 2nd gen

I've had this truck pretty much stock, only with 32 inch BfGoodrich KO2s, a small lift and a bull bar. I'm at a position now where id like to upgrade it, the plan is to get an ARB deluxe bullbar and 35 inch tires. (i am aware of the upgrades id have to do in order to fit those tires)

Now, the MPG I get on my current setup is around 11-12 MPG, all city driving and a lot of traffic, or up and down hills. I do feel like i have to keep a pretty heavy foot while driving to keep my speed up, and I thought of re gearing to be one of the first mods as im pretty worried my MPGs will only get worse. The shop I talked to recommended 4.56 Gears, but im sure they thought ill be keeping around 33 inch tires. I had been looking into 5.29 gears since im going for 35s and quite a lot of extra weight with the bull bar and maybe an overland setup. After a bit of investigating, maybe its too aggressive since its only a 5 speed auto, also the recommended the 4.56 so im leaning towards the 4.88.

Will going for more aggressive gears help with my MPGs on the city and daily driving?

Will the 4.88 and 35s leave my truck on similar to stock gearing (id prefer to keep a regeared feeling since I do a lot of elevation changes on highways and dont want to go 3/4 throttle to keep 70 mph).

 

4.56 for highway driving
4.88 for lower speeds and high RPM


I will be going 4.56’s when I get 35’s. 4.88 is overkill.