lifted towing power/mileage

I tow a 4300lb loaded landscape trailer two days a week, my tacoma has a 3" lift w/ 33x12.50x17 and I get horrible gas mileage while towing (not to mention I can't maintain highway speeds in D, it always searchs for the right gear). I already have a K&N cold air intake and flowmaster muffler, is there any other mods I can do w/o a supercharger to get more power and better mileage or would I be better off going back to stock tires/suspension?

 

regear to get stock or even lower than stock ratios back. Use the tire size calculator to decide what gears to go with.

 

Don't try to tow in D if it hunts- That'll damage your transmission.
Get rid of the Flowmaster cause that only hurts your power in sacrifice for sound.
And realize that towing that much weight is going to have bad mileage no matter what. I would say if you tow a trailer like that so often- I would get a larger truck.

 

You should most likely regear or get smaller tires and never tow in OD. Here's a link for geared 3rd's from East Coast Gear Supply.
http://eastcoastgearsupply.com/i-788575-tacoma-non-eld-t100-tundra-3rd.html