I have two front tires that are nearly bald, and two rear tires with a lot of tread life. I intend to go to non-runflats, but was wondering can I have runflats and non-runflats on the car until the other two wear out?

 

Yes you can. Put the better newer tires together on the rears.

Replace the older tires when you can with the same non runflats.

This has been discussed before, search for similar threads.
https://www.northamericanmotoring.co...d.php?t=107509

Try to keep the size the same front and rears- 205/45-17 but it is possible to mix sizes if it is very close like 215/45-17. Or similar if you have 16" wheels. 205/50-16.

 

IMHO, you'd have to be pretty desperate to run two different types of tires at opposite ends of the car. I can't imagine what the affects to handling would be, but I know I wouldn't do it (but then I'm just an old guy from the old school).

A good reason for rotating tires on a regular schedule. Then they all wear out at pretty much the same time.