Does anyone know what is the SC OEM Tire Load Index number???
Today I went to the Costco for some new tires and they're hesitant to install 19s....(since it's not stock)
Costco will do it if the front Tire Load Index number need to be below 91Y and 96Y for the rear.

Thanks,

 

Do you know if the rim machine they have will damage the lip on the rims?

 

You should find that info on the drivers side door jam on a placard.
You can always ask Tirerack. They are a club Lexus sponser and you might get a better deal. Something you might consider as well, is the amount of p.s.i you can fill the tire to. my Michelin tires allow a 50 p.s.i inflation. I filled them up to the max preasure and I gained 2 mpg. That is an extra 40 miles per fill up! FREE! I am getting 23mpg now on my SC400! That is without trying. No cruise control and driving @ 75 to 80 mph!

 

It's in the SC manual. As I remember, it's above 91.