Getting a new yaris, couple ?'s

[bzinn 1]

You can do 18s on the car with a mild drop like TRD and a few other springs too.

Try to get rims that are not heavy as it does effect milage quite a bit.My 17s with tires are 4lbs heaver tahn stock and best milage I got was 32mpg out of a tank.Many here get 35+

Strut upgrades are needed sooner once you drop,but it all depends on how car is driven.

As for rougher ride,mine feels just as good with 205 17 45 tires as it does withthe stock tires and wheels.