Diesel power for the Discovery 2 came from a brand-new engine, which Land Rover called the Td5. Continuing the metrological theme, its development programme was codenamed ‘Storm’, and it began life as a member of a family of engines designed to replace Land Rover and Rover cars power units. The family was a development of the ‘Prima’ range of engines used in Rover cars and the Freelander, and was based around a 500cc per cylinder modular design. Approved in 1993, it survived for only a few months before BMW acquired Rover. Only the five-cylinder version survived the encounter, there being no suitable equivalent in BMW’S power-unit stable. It was innovative in using electronic unit injectors (EUIS) because common-rail technology was then not thought to be sufficiently mature. Each cylinder had a digitally matched EUI that injected fuel at extremely high pressure for maximum control. The control unit, codenamed ‘Thunder’, was developed in-house and provided a variably sensitive electronic throttle control. Serviceability was key, with another innovation in the form of a centrifugal oil filter allowing 12,000 miles (20,000km) between oil changes while a micron-fine filter and return fuel cooler provided the clean, cool fuel demanded by the EUIS.
The five-cylinder Td5 engine was the result of a major development programme that became one of the most well-respected and reliable of Land Rover power units.