Before 1994, Land Rovers wwere available with either the 2.5-litre 200 Tdi engine or the 3.5-litre Rover V8. The 2286cc 4cyl, ohv, indirect injection, diesel was first used in S2A, S3 and early 90 and 110s. A five bearing crank-shaft was introduced in 1980. The original transmission was a dual-ratio five-speed manual with drive via a transfer case with a lockable centre differential. ..
The 200TDI (1990 - 1994) 2495cc, 4cyl, ohv, direct injection, diesel (nominally 2.5L). natural aspiration developed 85bhp at 4000rpm, 150 lb-ft at 1800rpm. The turbo version developed 107bhp at 3800rpm, 188 lb-ft at 1800rpm. This engine is still in common use as a hardy, reliable power plant
In 1994, the 200Tdi engine was replaced by the 2.5 L 300Tdi 4 cylinder engine with Bosch electronic emissions control for certain models. At around this time, a stronger R380 gearbox was fitted to all manual models.
The Series II Discovery debuted in autumn 1998. The 2,495 cc Td5 in-line direct-injected electronic management was smoother, producing more usable torque at lower revs than its 300Tdi predecessor. The Td5 engine was derived from the Rover L-series passenger car engine.
Marketed as the LR3 in the USA, Land Rover introduced the Discovery 3 in 2004. The engines were all Jaguar / Ford/ PSA-developed 2.7-litre, 195 hp (145 kW), 440 Nm V6. These vehicles were fitted with multiple electronic traction control systems including the 'Terrain Response' systems where the on-board computer selected the gearbox settings, suspension height, differential lock and throttle response of the engine.
In 2009, the Discovery 4 was released with two engine options from Jaguar Land Rover's Gen III. The TDV6 Gen III was a 3.0-litre development of the 2.7-litre engine used in the D3 with twin-sequential turbochargers. Fuel economy, power, torque and exhaust emissions were improved. In 2011, the 2.7-litre engine was dropped and two versions of the 3.0-litre engine were made available – the TDV6 and the SDV6 (the latter offering 245 bhp).
Tuning the Land Rover Diesel engines
Just as with any other engine, no amount of tuning will improve an engine that is not running correctly in the first place. Also, an engine typically delivers less than half of its power to the wheels with every related system (air con etc) robbing power from the wheels. Unlike petrol engines, diesels are designed to provide maximum torque at the low end of the RPM range. It delivers its greatest power to climb hills, tow trailers etc at low and medium RPM.
The starting point is to ensure that the engine is performing as designed, meaning that fuel and air settings are correct, air intake is as efficient as possible, the exhaust system is clear of blockages and the injectors are delivering fuel at the correct pressure and spray pattern.