I have a w209 Recently I got a flat tire and had to change it because I was driving back home on the highway because I can not go on the highway with my spare. The original tires that came on my car were the continentals sport (w rating). The only tire that was available was the michelin sport (z rating). So I was wondering if its ok to drive them until I have to change them even though they are different or do I have to chaneg them all to one kind of brand and/or rating?

for the most part, it isn't a big deal when u mix tires... just don't mix something like snow tires and summer tires. just wait till the conti's are worn out before u change to michelins...unless u have money to burn. there isn't anything available in another size? i find that hard to believe. was it online or local shop? try tirerack.com or tires.com...they have extensive selections.

Don't drive on different tires for too long. Handling will be completely out of whack especially in the wet. Make getting this fixed a priority.