Concerned about using 285/75 R16 tire size without regearing.

I recently replaced my Tacoma and the new one I purchased has 285/75 R16 C load BF Goodrich All Terrain KM2 tires. This restricts me from putting the spare wheel under the truck which is crucial for me living out of the topper on the back. I currently have a swing gate tailgate, which I am selling. I would like to put 275/70 R16 tires on there in order to increase the acceleration and decrease the rotational weight (improving gas mileage).
But I noticed that the 275/70 R16 size tire only comes in an E weight. The truck has a 2" lift and a ARE DCU commercial 30"-36" topper on it, designed for living. So there is some added weight.

Should I care and will i ever noticed the difference in?
What would the benefits of regearing to 4.56 do

 

Just keep in mind that tire size is not very common. My discount tire doesn't stock anything in 275/70, they have to special order. You may be on your spare a while in the case you had a blowout/NR tire and needed a new one. But, don't let that stop you from getting the tires you want.

Now about the weight, I bought my truck stock with a leveling kit and 285/70/17 goodyear paper thin tires. It was pretty quick, and could do burnouts (4.0L). I put on same size STT Pros E rated and it put me just over that line where I can no longer do burnouts. They are heavy tires, we're talking ~65lbs. I then of course added a steel bumper (~120lbs) and a winch. The power difference really doesn't bother me since I don't race my taco and don't care much for burnouts. I get about 14mpg best case interstate driving. Cold air intake helped restore some power. The only time I wish I regeared is on the interstate, with that weight/tire combo my truck doesn't shift into O/D until I reach about 85, which is annoying to me because I don't like doing 10 over the whole time but also don't like my rpms in the 3,000+ range. And my exhaust is annoying on the interstate. If I had $1,000 to mod my truck would I regear it to 4.56? Probably. Would stock gears stop me from buying heavier tires again? Nope.

All depends on what you use the truck for. I like 10 ply tires, makes my truck feel stronger

 

just bend the tabs out that hold the spare in place

 

If this is for a 2nd/3rd gen truck you are able to fit those tires in the stock spare location with a little modification. I did not have to bent the tabs back. I did have to move the tire holding/lifting device rearwards. This required drilling two holes.

 

I hated the loss of power with 33's, and I had 255/85s. You being in Colorado,I would re-gear or go to 265/75s

 

It wasn’t too bad for me. Got 285 put on today and drive ability wasn’t bad at all. Had to put more pedal to the metal sometimes but I thought it would be A LOT worse.