In 1987 you could buy a Ford Sierra Cosworth RS500 for £19,950. In February 2023, the finest known example — a 5,192-mile black 1987 car kept with forensic attention to originality — sold at Silverstone Auctions’ Race Retro sale for £596,250. Against an estimate of £150,000 to £180,000. That is the story of the RS500: a blue-collar performance car that has quietly ascended into blue-chip territory.
What Made the RS500 Different
The Sierra RS Cosworth had already established itself as one of the greatest Group A homologation cars of the 1980s when Ford decided it needed to go further. To remain competitive in touring car racing, Aston Martin Tickford was commissioned to hand-build an evolved version from 500 existing RS Cosworths shipped from the Genk factory in Belgium.
What Tickford delivered was the RS500. Externally, the changes were deliberately subtle: a front splitter with additional cooling vents, a secondary rear spoiler beneath the iconic whale tail, and RS500 badging. Under the bonnet, the transformation was more significant. The 2.0-litre Cosworth YB engine received a Garrett T04 turbocharger, larger intercooler, twin fuel injectors per cylinder, and pressurised oil-cooled pistons — raising road output to 224bhp with the real prize lying in the racing versions, which reliably extracted 500bhp and beyond.
On the road, the RS500 was only marginally faster than the standard Cosworth — 0–62mph in 6.2 seconds, 153mph — but that was never the point. The RS500 was a racing car with a number plate. Its engine architecture unlocked power that the tuning industry seized upon immediately. With injector ports plugged, 350bhp was achievable with minimal effort. In the late 1980s and early 1990s, tuning firms competed to extract 500bhp from a car that still looked, from the outside, like a Sierra.
Group A Domination
On track, the RS500 was devastating. It dominated the British Touring Car Championship, won the European Touring Car Championship, and conquered touring car series across Australia and beyond. Andy Rouse, among the most celebrated BTCC drivers of his era, became synonymous with the RS500’s motorsport legacy after unlocking its full potential through a radical suspension setup.
Of the 5,545 Sierra RS Cosworths built, only 500 were converted to RS500 specification. Of those, the 392 finished in black represent the most recognisable — and now most sought-after — examples, though white and blue cars also exist.
What Is a Ford Sierra RS500 Worth Today?
The Silverstone Auctions world record of £596,250 commands the headlines, but the broader market tells an equally compelling story. An RS500 in average condition now commands around £100,000, with clean, low-mileage right-hand-drive examples regularly achieving £150,000–£250,000 at UK auction. The key value drivers are mileage, originality, service history, and — critically — that the car remains unmodified and unmolested. Decades of heavy modification and, infamously, high insurance premiums in the 1990s mean that genuinely original, standard RS500s are now exceptionally rare.
Buyer’s essentials: verify the matching chassis plate and engine number, confirm the Tickford conversion plates are present, check for period modification (injector plugging, turbo upgrades), inspect the bodyshell for accident damage repair, and seek out a full history file. Tremona Garage in Southampton and other recognised fast Ford specialists are the names to know for pre-purchase inspections.
Agreed Value Insurance — Not Optional at These Prices
The RS500’s trajectory from £10,000 in the late 1990s to six figures today makes one thing absolutely clear: standard insurance is wholly inadequate. Agreed value cover from a specialist who understands the Group A homologation car market is the only appropriate protection for an investment at this level.
QuoteZone lets you compare specialist quotes for your Ford Sierra RS500, alongside any other classics or performance cars in your garage, and every vehicle in your household — all from one straightforward search.
Five hundred built. One legend. The RS500 is the most valuable Ford Sierra ever made — and the gap to everything else keeps growing.
Use the QuoteZone link on this page to compare insurance for your RS500 and every car you own — the right agreed value protection, properly benchmarked to today’s market.
