on both models was now mated to an all-new five-speed LT85 manual gearbox. The year 1986 saw improvements in engines to match the more advanced offerings by Japanese competitors. The "Diesel Turbo" engine was introduced in September, a lightly turbocharged version of the existing 2.5-litre diesel, with several changes to suit the higher power output, including a re-designed crankshaft, teflon-coated pistons and nimonic steel exhaust valves to cope with the higher internal temperatures. Similarly, an eight-bladed cooling fan was fitted, together with an oil cooler. The changes for the turbo diesel were kept as slight as possible, in the aim of making the car saleable in Land Rover's traditional export markets across the globe. The 2.5 diesel, 2.5 petrol and Turbo Diesel engines all shared the same block castings and other components such as valve-gear and cooling system parts, allowing them to be built on the same production line. The Turbo Diesel produced , a 13% increase over the naturally aspirated unit, and a 31.5% increase in torque to at 1800 rpm. Externally, turbo diesel vehicles differed from other models only by having an air intake grille in the left-hand wing to supply cool air to the turbo. Early turbo-diesel engines gained a reputation for poor reliability, with major failures to the bottom-end and cracked pistons. A revised block and improved big end bearings were introduced in 1988, and a re-designed breather system in 1989. These largely solved the engine's problems, but it remained (like many early turbo-diesels) prone to failure if maintenance was neglected. At the same time that the Turbo Diesel was introduced, the V8 engine was upgraded. Power was increased to , and SU carburettors replaced the Zenith models used on earlier V8s. Sales turnaround The new vehicles with their more modern engines, transmissions, and interiors reversed the huge decline in sales that took place in the 1980s (a 21% fall in a single year, 1980–1981). This growth was mainly in the domestic UK market and Europe. African, Australian and Middle-Eastern sales failed to recover significantly – Land Rover had not been immune to the poor reputation caused by substandard build quality and unreliability which had afflicted the rest of British Leyland, of which Land Rover was still part. In these markets Japanese vehicles such as the Toyota Landcruiser and Nissan Patrol gradually took over what had been a lucrative export market for Land Rover for decades.