OHTSU is a cheap, decent tire brand.

based on your posts, with mileage, extra air pressure, etc. Why not try a 175/65r14? Its not too much of a compromise, its narrower for less rolling resistance, its taller for more distance per rotation, and a cheaply available tire. ($42.99 for a "common" FR380).

My tires are almost always around 10k miles. The mileage warranties aren't necessarily a warranty, but an expectation. If it is treated as a warranty, then it typically requires proof of maintenance that costs more than a set of tires over the time for the tread life (the rotations, alignments, etc) and most tire places I have been to rarely honor the mileage, I found one in my life.

The only things you can use to guess the length of life is the treadler rating, the higher the number the longer the should last. Its a standard number to directly compare between brands. The "miles" number is used as a similar comparison of this, not a guarantee of life with all the loopholes:

Understanding Tire Warranties

this is a good read.