Tyre Size: 145/80R13 (145R13) | Lotus Seven S3 1968 to 1970

The original minimalist sportscar for the road. Built from 1968 to 1970. Originally fitted with a 520-13 crossply tyre, with a 145SR13 radial option. A modern radial replacement for a crossply equipped car would be a 145SR15. In 1970 it was possible to order a car with wider tyres, such as 165SR13, or even 185/70HR13.

When the Lotus Seven Series 3 replaced the Series 2 in 1968, it took a true enthusiast to spot the difference. All Sevens now came with flared wings with no cycle wing option (the S2 was available with both designs) and the rear wings were widened to accommodate the Ford Escort Mexico rear axle that replaced the Standard 10 item fitted up to now. The front drum brakes were swapped for discs and the electrical system switched to negative earth.

While there was little to distinguish the Lotus Seven Series 3 visually, under the bonnet things were changed considerably. The base engine was a 72bhp Ford 1300 Crossflow unit, although 1598cc versions of this same powerplant was also offered; 84bhp in standard form or there was a 120bhp Holbay option.

However, the ultimate Lotus Seven Series 3 engine was the Lotus Twin-Cam unit which offered 125bhp and 0-60mph in just 6.2 seconds. Known as the Twin Cam SS, just 13 were made, priced at £1225 in kit form. These are now the most collectible Lotus Sevens of all.

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