Brand: Pirelli, Tyre Diameter: 15 | Porsche 924 Turbo 1979-1983

Part of the set of upgrades on the Turbo variant, the car gained 15 inch 5-bolt wheels with the standard Porsche PCD, and these were fitted with 185/70HR15. There was also the option of fitting a 16-inch wheel with 205/55HR16 tyres.

Originally designed for VW, Porsche bought the 924 design back in a clever move to expand their model range beyond 911 variants. Its sales success kept Porsche in business, and further development into the 944 and 968 mean the front-engined, water-cooled 4-cylinder range is a bigger part of the company's history than its branding would suggest.

Porsche's early adoption of road-car turbocharging, following its successful use in their competition programmes, made it an obvious choice for boosting the performance of the 924. There were upgrades to braking, suspension and cooling. A very effective performance car, it received an engine management upgrade in 'S2' form, and formed the basis for the competition variants of the 924.

Porsche has a history of working closely with tyre manufacturers to specify the best tyres for their cars, and these are commonly marked with a "N' number to indicate approved Porsche fitments (N0, N2, N3 etc).