During the 1960s, tyre manufacturer began to wake up to the advantages of radial technology, as first demonstrated by Michelin with their X used on the Citroen Traction Avant. A radial tyre is different to the then standard cross-ply by separating out the function of the sidewall and tread of a tyre. In a crossply, the textile plies of the casing run across the carcass diagonally, with each ply crossing the adjacent one at alternate angles. A radial tyre has plies which run around the carcass parallel to each other radiating out from the wheel centre, together with a layer of bracing around the tyre under the tread. This creates a tyre with a more flexible carcass but braced tread area.
Dunlop realised that they could harness this type of tyre design to create tyres which offered real advantages in performance, longevity and handling, and spent over 15 years researching the mechanics of grip in order to create their revolutionary SP Sport. This was a marked leap forward from not only cross ply tyres, but the SP68 and SP41 radials it superseded.
Dunlop focussed on the three main areas of achieving maximum grip. The carcass design should mean that the maximum amount of footprint is on the road. When this is achieved, on dry roads the main factor in grip is the type of rubber compound used. However it is on wet roads, or even damp ones, where the tread pattern really comes into play, and the Dunlop designers created a brand new type of pattern that actually “pumped” water away from the tread surface and out of special ducts on the side of the tread. These were known as aquajets, and that became the name commonly adopted for the new tyre. In this video: "Dunlop Aquajets in Action" you can see the aquajets at work. In fact they are so efficient, it was claimed that at 50mph they could “pump” a gallon of water a second.
As its advantages became clear and reputation grew, Dunlop’s Aquajet became standard fitment on the performance cars of the day, first being employed in different sizes on the Mini Cooper and Jaguar E type. It became the must have upgrade on anything from a Triumph Dolomite Sprint, through Ford Cortina, to Lotus Elan.
These great adverts from the period show how fitting an SP Sport could help you lead the life of an international playboy or spy when driving your Jaguar XJ6.
The Dunlop SP Sport Aquajet is still made from the original moulds, in England. The tyres produced today are better than they have ever been, as they take advantage of the latest compounds and rubber technology which means they perform and last brilliantly, whist retaining their authentic appearance and characteristics.
Now in stock are the 185R15, ER70R15 (205/70R15), 165R13, 145R10 and 165/70R10. This means the ultimate period performance tyre is available for lots of classics such as Jaguar Etypes, Lotus Elans, BMW 2002s, and Mini Coopers; and there are sizes being reintroduced regularly. If you drive an iconic car such as this, it makes sense to fit the iconic tyre.