THE ENGINE TO SAVE THE SEVEN

Caterham needs a replacement for Ford's out-of-production engines. Its solution is a 1.3 turbo from Horse Powertrain, a specialist owned by Geely and Renault. We get to know the new powerplant - and drive it in a prototype

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CATERHAM HAS BEEN FACING A conundrum.

Three of them, in fact. 'This is the first time in the company's history we've had to replace an engine, gearbox and differential at the same time,' explains CEO Bob Laishley. Ford's 1.6-litre Sigma, which has powered plenty of road- and race-spec Sevens over the years, ended production in 2020, so Caterham has been constructing Sigma engines from new spare parts in the interim, but a permanent replacement was required. Likewise, many current Sevens use the five-speed gearbox from older Mazda MX-5s and the limited-slip diff from the previous-generation BMW 1-series. Mazda hasn't manufactured the five-speed for some time, and although BMW agreed to extend the diff's manufacturing run for the Dartford-based firm, that too must now come to an end.

Caterham has examined replacement options for all of the above from multiple suppliers, but making them fit within the Seven's diminutive chassis is a complex challenge. For the engine, it has settled on a 130bhp 1.3-litre turbocharged inline four-cylinder from Horse Powertrain. Not a household name but a big operation: owned by a combination of Renault, Geely and Aramco, Horse has manufacturing capacity across 17 plants and five R&D centres across three continents, with its HQ in the UK.

The chosen engine's official name is the HR13DDT and it has a complicated history of owners prior to the formation of Horse Powertrain in spring 2024. Originally created under a prior Nissan-Daimler-Renault alliance, variants have appeared in cars such as the Renault Clio, Nissan Qashqai and Mercedes A-class. It's built in large volumes at a plant in Valladolid, Spain, and it meets emissions requirements to allow Horse to build the unit more than ten years from now.