I have a 96 Tacoma 4x4 with 31x10.50x15 tires on it.

It seems like every Toyota that I see like mine has 31x10.50x15s on it.
Lately I've been thinking that 31x10.50x15 is kinda silly and almost balloon like looking.

I have noticed the factory size recommended on the inside door sticker is much smaller.

It seems like many people use 31x10.50x15. Is there any reason why this is the standard for replacement tires even though the factory recommends much smaller tires? Is it just because 31x10.50x15 "looks cool" ? Or is it because it's about the biggest tire you can put on a stock taco without a lift? Is that where the trend came from?

I saw two Tacomas in my neighborhood today with sizes other than 31x10.50x15-

I saw one with 30x9.50x15 and one with 29x9.50x15.

One thing I noticed is the smaller tires give you way more clearance and overall seem like a much more sensible size. The smaller size is probably easier on your truck too- less wear and tear on your drivetrain I am guessing.

Have any of you gone from 31x10.50x15 to a smaller tire? What were the results? It seems like a smaller tire might be better? Am I right?

I am thinking of going 30x9.50x15 next time- seems like a nice compromise- and gives you more clearance and less of the balloon look.

 

The smaller diameter (31, 30, 29) will give you more "off the line power". It will also give you a higher RPMs at highway speed. The higher the RPMs the worse gas mileage. Also a bigger dia will require more power to hold a speed which can use more gas. A bigger tire will "roll" over bigger obstacles while off-road. A bigger tire is heavier which uses more gas also.

What size does the door tag say is stock?

You can also get a narrower tire in the 31s. Like a 235/75R15. it is 31x9.4x15

 

I know that 31x10.5 is stock size for my v6 auto Runner...

 

It's not necessarily the 'recommended' size, but just the stock size on 4x4's not taking into account optional packages where the 31x10.5x15 size is/was the OEM fitment.

I had a '93 4x4 SR5 extra-cab truck, with the door sticker that had the standard 225/75R15 tires listed. However, my truck was equipped with the optional 31x10.5R15's, with lower gearing installed in the diffs from the factory to compensate for the larger tires.

Of course you can do whatever you want, but I'd find out what size of tire your truck came with stock, before downsizing.