Supply and demand and wholesale pricing factor into the tire choice. When you order your new car, even today it only says the tire size, not the manufacturer and model. You don't find out until you get it. And my in-laws and I had the same model, same year, same package car bought new but had different tire models. Running year change or substitution I don't know, but to the automaker tires are tires.
Goodyear Polyglas were more expensive than the Firestone Wide Oval, so not used on the base model cars; but on performance cars the extra cost also gave a performance boost.
I can attest for this being correct ,at least on Volvos...they came with Dunlop, Michelin and Pirelli from the factory...I used to look for the car that came with Michelins....today I think they come with only Michelins , unless there was a shortage of those at the time of building the cars...then they would mix in other brands,... but as Vikki stated before , BEST way to find out is if someone has the glove box kit with tire warranty left...it would then be "for sure"...
Last edited by Bjorn Sefeldt; 07/25/0702:17 PM. Reason: spelling
