The compact spare saves weight, and is almost a perfect match for tire diameter. Great for flats when not far from home. But the owner takes long 400 mile trips, couple times per year, and although flats are rare, could happen 200 miles from beginning or trip end, and at night. With her prior Audi A4, I came up with a full speed spare, so she could install it or get it installed and be on her way at frequent 80mph speeds.

The Canadian C230 came stock with 16x7 47mm offset wheels (same offset as all C300 17" fronts) , and 205-55 tires. I searched TireRack for C230 wheels, picked one, and TireRack said no 16" wheel would fit --- caliper interference .

The C230, and US C300 Lux and Sport all have 11.6" front discs with BIG calipers, and 11.8" rear discs with smaller calipers.

I bought a wheel anyway, and fit tested it. Note that all the US W204 17" oem's are 47mm offset, and about 23 lbs.

Rial Como 46mm offset, 19.5lbs

It cleared the rear caliper easily, and had about a .21" minimum gap to caliper up front. The weights should be add between spokes to the exposed outer rim, and at the inner most area, for THIS wheel to maintain .21" clearance.

I check fitted the wheel in the trunk. I think with tire, the cover will be flat or close to it. I do need
to modify the anchored plastic cylinder (with round threads molded on the OD) that the plastic tool assembly engages to hold down the spare. It needs to be higher with the new wheel. Got a few ideas.

Another possible wheel that was cheaper and lighter:

Sport Edition F10 45mm offset, 17.5 lbs.

This would have to be test fitted. I'd be happy to give how-to details.

Two other 16" wheels that are known to fit:

Borbits + snows

MB Replicas, C300 owner

205-55-16's at all 4 corners would be THE BEST for winter tires in hard winter areas, or just a more comfortable ride with all season tires, but less crisp handling. The tires could have the same 91H SL load and speed rating as 17" oem's, but I'd go with 91V's for stiffer sidewalls as a spare.

Fuzion V rated All Season

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Well, the 16"x7" rial wheel noted above, with 205-55 Cooper 91H Response Touring tire, fit in the rear spare wheel-well perfectly, as predicted. Normally it takes ~3 turns of the jack-carrier-nut to hold down the temp spare, and now ~2.5 turns to hold down the new High Speed spare. The black cover board is still perfectly flat, but a bit more sturdy due to the tire support below.

Got a pic but can't post it, unless someone wants to host it who already has a photo site they use.

205-55-16 91H tires/wheels is a valid spare concept for C300's (and some C350's). For long high speed trips, it's a great convenience for that occasional flat tire. Cost is couple hundred bucks, and about 20 lbs extra. They can even be used as a set of MONSTER SNOWS for those in hard winter zones.

Post by C350 owner with 16" winter wheels ... read rest of 1 page thread.

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