I've read many posts on replacing RF with non-RF which I plan on doing, but the one thing no one has mentioned...are you purchasing tires with the weight and speed rating suggested by BMW? If not how far off the rating did you go?

Mine are rated 87v's and am wondering how low I can go.

 

minimum, both on weight class and speed rating. On prior vehicles I have noticed the weight class can vary with different OEM diameters too (and not always higher w/ lower profiles like I would have guessed). Most relevant for high speed, high temp, high load use, but why compromise. So many good tire choices out there.

 

I would agree with those as the minimum requirements. I would be weary going below those.

 

My manual has approved examples a lot lower than 87V.

 

Honestly, most tires within a size range will have similar load ratings. Same goes for wheels you're going to be interested in running.

This is a case of worrying too much. The car weighs 2650lbs, it's rather light weight compared to a lot of other modern cars, that also use 205/45 size tires for 17" wheels (such as a VW Passat).

Unless you're trying to cheap out on tires? But that's foolish - what's your life worth?

 

One of the local shops told me I could probably get away with next lower speed rating but cautioned against going lower on the weight.

Another shop quoted me 87H tires and am thinking that might be too low. However, its a difference of 45 dollars a tire.