Alan Kenny, courtesy of Silverstone Auctions

The original Ford Sierra RS Cosworth was the first Ford to wear the Cosworth badge and was presented to the public at the Geneva Motor Show in March 1985. Launched for sale in July 1986, and based on the 3-door Sierra body shell, it was designed by Ford’s Special Vehicle Engineering (SVE) and was powered by a Cosworth-designed 2-liter turbo engine of now-legendary repute.

In total 5,545 cars were produced — of which 500 were sent to Aston Martin Tickford for conversion to the Sierra RS500 Cosworth. If the RS Cosworth was a homologation car, the RS500 was an evolution special. The RS500 was announced in July 1987 and had a mechanically uprated Cosworth engine (more similar to the one to be used in competition), with power boosted to 224 horsepower, modified bodywork and the cachet of being hand-assembled.

Recently refreshed and with a fresh MOT, E378 TKN will be presented at Race Retro on its original wheels. Silverstone Auctions are proud to have been involved in the sale of many cars at world-record prices, many of them Fords. With Fast Fords seemingly knowing no bounds in their desirability, and this one believed to be the very best example of the ultimate 1980s Fast Ford, we invite and encourage any serious collector to inspect this superb, 5,000-mile Cosworth, as its type is unlikely to be found again.

SCM Analysis


Vehicle:1987 Ford Sierra Cosworth RS500
Years Produced:1986–87
Number Produced:500
Chassis Number Location:Plate riveted to hood slam panel
Engine Number Location:Right side of block between alternator and engine-mount bosses
Club Info:Ford RS Owners Club
Alternatives:1987 Alfa 75 Turbo Evoluzione, 1989–91 BMW M3 Evo/Sport Evo, 1989–91 Mercedes-Benz 190E 2.5-16 Evo

This car, Lot 508, sold for $707,302 (£590,500), including buyer’s premium, at Silverstone Auctions’ Warwickshire, U.K., sale on February 25, 2023.

Silverstone Auctions has always done well with Fast Fords, but this one tops the lot. It’s possibly the best of its type in the world and, following a battle between two determined bidders, it sold for four times what anyone expected.

The hottest hatch

These “Cossies” are hot stuff — literally. As well as being coveted by Ford fanciers as a latter-day Lotus Cortina (you’ll feel the DNA continuance if you drive them back to back), they were once the most-stolen car in the U.K. They were conceived and built so that Fords could win at touring-car racing, selecting the unloved “jelly-mold” rear-drive Sierra as the most suitable base, and using chassis-development knowledge gained from racing the Merkur XR4Ti (similar car, different name) in the U.S.

Cosworth created the engine using a twin-cam, 16-valve head and turbocharger on the faithful old Pinto bottom end, the resulting “YB” lump churning out a bit over 200 hp in road trim, or nearer 500 with the wick turned right up in a racer. The gearbox is the BorgWarner T5, as used in the Fox-body Mustang. The aero package with huge wing on the hatch was to negate the standard 3-door Sierra shell’s positive lift, the fender extensions were to allow fatter (though not fat enough) rubber for racing, and the nose intake was to feed air to the intercooler. Ford had to make 5,000 to qualify for racing in Group A — a class that appears fairly standard on paper but, with sinister, hunkered-down stances and flame-spitting exhausts, looks and behaves anything but. Smokey Yunick would have had a grand old time exploiting the rules.

For its “evo” cars, Ford took 500 of the Genk, Belgium-built RS Cosworths, all produced in December 1986, and trickle-fed them to Tickford, which had been responsible for finishing Ford’s RS200 Group B homologation cars. Most of the 500 were black, with only 56 in white and 52 in Moonstone (blue-gray). In the Sierra’s case, as well as some minor body and aero changes, the mods were basically a bigger (T04) turbo and an extra set of injectors to squirt in more fuel, though these aren’t functional on the road cars. Sadly, little could be done to address the Cossie’s main weakness as a race car, in that it didn’t have enough tire for its weight and power.

The RS500 wasn’t homologated until August ’87 but that was enough to win four rounds at the back end of the 1987 World Touring Car Championship, having taken poles in the last six. Other successes included the 1988 DTM Championship, 1987 and 1988 Australian Touring Car Championships (plus two Bathurst 1000 victories), 1988 and 1989 Japanese Touring Car Championships and the New Zealand Touring Car Championship in 1989, 1990 and 1992. It also won the British Touring Car Championship, but not until 1990 (the grids then being full of them).

Original and sublime

The back story on our subject car is that our vendor, “a knowledgeable and particularly fastidious enthusiast,” according to Silverstone, decided 15 years ago that he wanted an RS500 and focused on finding the best available. Where most Cossies had been extensively modified, this one was very original. Moreover, the mileage was nominal, showing only 5,192 miles, and it had patently been cared for.

Having secured an original car, the vendor tracked down NOS service parts, such as an original orange Fram oil filter. He also found a set of period RS500 wheels and tires so that the date-stamped originals, still wearing OEM Dunlop D40s, could be preserved.

During his ownership, though lightly used, it was regularly serviced and maintained by Tremona Garage of Southampton, a classic-Ford specialist with at least one previous concours win to its credit. Before sale, Tremona carried out a recommissioning service using all genuine parts, including OEM Motorcraft spark plugs and a black Weber fuel filter. The original Ford exhaust system is still in place, and the factory fog lamps are still in the boot — they were deleted on RS500s to supply more cooling for the racers but would have been fitted by the dealer on request.

This is probably the most perfect example you could encounter. The irony is that the RS500 is less nice on the road than the smaller-turbo versions, though bragging rights probably matter more to both owners and collectors. Interestingly, the Escort RS Cosworth that replaced the Sierra went the other way, starting with a big (T34) turbo and then quietly downsizing to a T25 once the required 2,500 homologation cars had been made.

So now that we have the perfect example of the most-collectible Sierra, what do we do with it? Not much, sadly. Its obvious problem is the very thing that attracted buyers to this pristine reference car in the first place. Having been properly preserved, putting miles or non-original replacement parts on it will hurt its value. That renders it practically unusable, though the new owner apparently plans to bring it out at one or two charity events and, according to the consignor, “He certainly isn’t planning on hiding it away.”

A staggering sum

The price? Insane for what most parties agreed both before and after the sale was a £120k car that might do £150k on a good day with a favorable wind — not far off Silverstone’s own pre-sale estimate of £150,000–£180,000 ($180k –$216k). The previous record price of £132,750 (then $177,739) was set by Silverstone on an 8,795-mile RS Cosworth in November 2022, having sold an RS500 in 2021 for $147,610.

This car isn’t unique, and the result might be repeatable by someone with sufficient reserves of money, patience and a stash of unused old-stock service parts. But it’s what sometimes happens when two people really want the same item, and the world-record (and then some) tag was a result of “a bidding war between an online bidder in Dubai and one in the U.K.,” according to Silverstone. Or a case of stubborn refusal to give up, if you prefer.

In the end, the British buyer prevailed, determined to keep this car in the U.K. You could call it foresight, but it’ll be many years before the rest of the market catches up with this investment. ♦

(Introductory description courtesy of Silverstone Auctions.)

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