Overwhelmed by tire choices. Need advice plz

[ben1620]

Hi I need new tires on my stock sport rims. Ive been reading old posts but have become more frustrated with so many choices. I have an '09 base +sport pkg. I am lookin to spend $300ish per tire or less. I can go higher if the advantages Re clear for my situation. But if there is a bargain tire that I should be looking at, I don't mind saving money. I don't plan on lowering my car. I wont be going to the track; just some twisty backroads. I would like better tread life and performance than stock tires(i just got my car with 12k miles on it and rear are almost gone). I won't be driving in the rain. Does anyone have an estimate for mileage on different tire for daily driving?

First, should I consider changing sizes? I don't want to change my tire rpm's much so it would be 255/40/19 and 285/35/19. Or maybe change one and leave the other? Advantages & disadvantages? Is it worth the inconvenience of the speedometer being off?

This larger tire setup would have a slightly larger side-wall. What effect would that have on a tire like Hankook with a softer side-wall?
I know this has most likely been discussed but I can't find a post that clears things for my situation. Thank u for any help.
Ben