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Roadstars

    Roadstars (also known as BMW Style 40) are the original equipment wheels for Z3 M Roadsters and Coupes; the set that were on the car when I purchased it were showing their age and had sustained more than one curbing event. I wasn’t enthusiastic about mounting new tires on beat up wheels, and I also didn’t want the car perched on jack stands for a month waiting for the wheels to be refinished.

    After looking at available aftermarket wheel options that would fit the M Roadster, I wasn’t particularly interested in going to an 18″ wheel and couldn’t find a 17″ wheel style that I liked better than the Roadstars.

    What is it with BMW aftermarket wheel styling and the spiky antler look? Most of the choices with the correct bolt pattern, offset, and staggered fitment are variations of the same basic Y-spoke antler design.

    My tastes lean towards painted steelies with Baby Moon hubcaps, old school American Racing “Torq Thrust” in Antrhacite gray, or maybe a set of chrome Cragar S/S five spokes. Yes, I am a geezer. All three are not particularly lightweight, but I have no plans to track the car. If I ever go with aftermarket wheels, to get the right sizing and styling I’ll be looking at custom built wheels.

    After an unsuccessful search for a nice set of used Roadstars, I took the plunge and bought a new set:

    Rear 17″ x 9″ Roadstar

    The rear Roadstars are 17″ X 9” wide with a +8mm offset (ET8); fronts are 17″ X 7.5″ wide with +41mm of offset (ET41).

    Apparently BMW changed Roadstar wheel suppliers over the years; the original set of wheels have “OSO” cast around the valve stem mounting boss:

    OSO Casting Mark

    The new set of Roadstars were manufactured by BBS:

    BBS Casting Mark

    The new BBS wheels don’t have any sort of casting mark around the valve stem mounting boss:

    BBS Valve Stem Mounting Boss

    The roundel center caps supplied with the new wheels are also somewhat different than the originals:

    New vs. Old Center Caps