Sure, it's small potatoes, but I wanna bump up from my current 31x11.5s to 33x12.5s on my 60 series w/2.5 inch OME lift. The question is whether that change will affect performance to any detectable degree. Mostly driving in desert these days, and beach, which is why I wanted the fatter footprint. Thots appreciated.

This sounds just about like the same thing my son did to his FJ60, it's his daily driver, he noticed no loss of performance other than above 65 mph, it is de smogged with a header, 3" Ironman kit, stock gearing.
he noticed a little change in taking off, on a hill in high range.
Butch

I swap from 235/75/r15's to 33x12.5's every spring and back every fall...When you put the bigger tires on, you don't really notice it a heck of a lot, the rig is a little more sluggish, but nothing major. But man-o-man, if you go back to the smaller tires that sucker will feel darn peppy!

But that's just on a '40 with 4:10's. Might want to go down in gears a teensy bit to make up for it. (long hills and such you really notice the tires)

Oh, and for top end...I could crank the 235's up to about 95, but i am stuck below 85 with the 33's.