cpeavey said:
I meant specifically the wider 8" rim width in the rear, instead of using 16x7" both front & rear. From a distance, can you tell? (Whereas I don't have any trouble distinguishing a coupe from a sedan at a great distance!)
To the uninitiated, probably no but to trained eyes, definitely yes. Those who know coupes can spot (relatively speaking of course, 10 to 20 feet) rim and tire peculiarities such as proper ride height, correct offset, correct tire width (too fat of a tire or too skinny of a tire). Looking at the rear of the CS is more obvious. Due to the rather narrow rear track an 8" rim with the correct 225/50 tires give the coupe a more proper and aggressive stance compared to the what has been described by some as "crab leg liked appearance" of the narrower rims and tires. The front ends of the coupe and sedan look almost identical, it's doubtful anybody can differentiate them from a great distance. Side of the cars, obviously.
Your view on using wheel spacers to widen the rear track is more complicated than it looks and sounds. Most modern cars that use spacers are mounted with lug bolts that can be simply lengthened by using longer bolts. The wheel mounting system of the CS uses nuts that are screw on fixed bolts that are attached from behind the rear axle hubs. Providing that you could find the correct longer bolts then the complete left and rear wheel axles need to be completely removed to disassemble and mount the longer mounting bolts. Also by using spacers that are thicker than 5mm, you'll lose the wheel mounting flanges that protrude from the axle hubs. To retain the wheels being hubcentric, the new spacers must have their own machined flange. If not then your rims and tires will be riding on the wheel mounting bolts and not on the hub creating a very dangerous situation for your car.
When Alpina designed this staggered wheel system back in the late 1970's, their engineering and designs were gleamed from their extensive experience in tuning and modifying Bmw's and also their 15 to 20 years (up to that point) of serious racing for Bmw's in particular the racing CSL's. Wheels are designed mainly to look good and if you are a world renowned company like Alpina which has unmatched engineering prowess then you could also design wheels for perfect wheel/tire dynamics--strength, lightness, handling and braking. These staggered 7" and 8" wheel sets were designed exclusively for the Bmw big coupes of this period, the 6 series and the CS, so the rather small front wheel well areas in conjunction with the suspension setups of these two cars might have also played a part for the narrower front wheels. These Alpina rims were manufactured by Ronal to Alpina design and specs.
What it comes down to is personal preference. Whether you prefer the same size wheels/tires all around or a staggered setup. It's up to you!!!
Bert
72 3.5 CSi
88 M6
PS. I've a newly reconditioned set of Alpina staggers but they have yet to be mounted on my coupe.
