DJWLDW

Jim

Sounds like you are confused again

Dennis

jimisbell

Dennis, I am always confused. I am an engineer and OCD in an imperfect world. I dont like, "well, its close." I like perfection and wont find in in the automotive world. I have been collecting cars for over 60 years (more than 150 of them) and they are never perfect, but I expect them to be. for instance is the bolt circle 4.5" or is it 116mm or is it 114.7mm , not the same. But in the aumotive world, its close enough. Like playing whack-a-mole with handgernades. Itteldo.

Bgw70

Jim, this pic may help with the tire sizes…regular vs spare. Note they are very close even though one is 17” vs 18”
hope it helps…also, here is the link to the calculator to try different tires.
https://tiresize.com/comparison/

DshngDaryl

So buddy, did you ever do an ebay search for "sc430 Spare tire" ?
https://www.ebay.com/sch/i.html?_fro...pare&_osacat=0

DJWLDW

The correct Lexus part number is: 42611-24430

Dennis

Wilson2000

That's how I bought mine, and it fits perfect! I paid more than I wanted to, but got one that cleaned up to look brand-new. The wheel size is insignificant. The diameter of the spare tire is what needs to match the diameter of the other tires (not to mention bolt pattern and size). Jim: your concern about the differential wear is correct but would only be an issue if the diameter of the spare was different from the opposite wheel.