Pontons were originally fitted with 13-inch wheels, but owners commonly move to 14-inch rims from later Mercedes (often with 123-chassis 300D hubcaps) for a better tire selection and to cure excessive sidewall flex, which meaningfully changes ride and handling. The correct original metric size is hard to source, with limited brand availability.
Wheels: 13-inch original, many upgrade to 14-inch
Mercedes-Benz Ponton · mechanical