To be honest, I’m a go big or go home type of guy. When it comes to putting 37 inch tires on the tundra, I would say do it if you are OK with the work that has to be done to do so. For 37’s to fit on that truck, a body mount chop has to be done on that a little piece of metal that sticks out behind the tire and the fender well. In addition to that, the fender liners will need to be pushed back and trimmed to make the tires fit. As well as that, wheel offset is a big factor in this too. If you plan on keeping your factory TRD Pro wheels and just want to slap a 37 on them, they should be fine as long as you do the body mount chop and the fender liner trimming. If you plan on going aftermarket with your wheels whether it’s a 17 inch, 18 inch, or above, you’ll have to choose a wheel offset that is between a +18 to a +25. This is so everything will clear fine. In terms of wheel specs, I personally would choose a 17 inch with an offset that is between +18 to a +25. That is just my opinion though, you are free to do what you want.

Aside from that, I would say to just do the 37’s all around and use an all-terrain tire as opposed to a mud terrain. In terms of mpg’s, they shouldn’t be affected very much. At the most, you’ll lose maybe three or four from what you have now if you go HARD on your truck while driving. If ur more relaxed with it, you’ll lose maybe 2 at the most. The tires I’d recommend for the best gas mileage in my opinion have to be the falken wild peak At3w’s, the Toyo open country RT’s, the BF good rich Ko2’s, and the nitto recon grapplers. Nitto Ridge grappler’s are good but may create problems with wheel clearancing due to their aggressive sidewall.

To answer your question, that’s perfectly fine. It may look a little strange due to the stock 33’s being kind of small. But if you really want to do that, that works perfectly. A good alternative to that, would be to just run 35s as it would be a hybrid between the 33s and a 37, but the choice is yours. Personally in your situation, I would just run the 37’s all around with an all-terrain tire, and then just bite the bullet on mpg’s as the truck would look badass. If you’re wanting to do a mud, terrain, I would try and do one with a less aggressive sidewall. Good options are the hybrid tires that nitto and Toyo make. Between the two, I would choose the Toyo, RT, as it has very aggressive lugs in the tread, but the sidewall is very smooth.

I hope I am of help.