Different Front/Back?

[8CA]

The front tires on my 330CI are worn (think i was driving around under-inflated too long) badly, and need to be replaced. Rears are in great shape.

I have Michelin Pilot Sports on there, but have been wanting to replace them with Yokohama's I had on my last car.

Is it crazy to replace the front tires with Yokos and leave the Michelins on the rear until they need to be replaced?

I don't want to replace all 4 if I don't need to.

[98M3_4]

You should be OK, although it's not the ideal. I suppose as long as they are both the same type of tire, i.e. both high perf front & back. I've done this with same brands but diff models front & back until I could change out the rears.