do the PSI change if I change the tire brand or model?
Short answer is NO. Always set pressures according to the owners manual, which for the R3 is 29PSI (200kPa) front and 36PSI (250kPa) rear. Pressures are the same for all load conditions, right up to the maximum load of 353 lbs. (160kg).do the PSI change if I change the tire brand or model?
That's true when you are making significant changes to tire sizes.The above answer also does not apply if you change tire sizes.