A faster edition called the 111S, named after the Lotus type-number of the Elise (Type 111), was introduced in early 1999 and had the 1.8 Rover K-series engine also used in the Rover MGF. It featured a VVC system providing continuously variable lift and duration on the intake valves only. This technology produced a flatter torque curve from lower down the rev range and a declared , a small but useful improvement over the standard 16 valve Rover 1.8 L K-series inline-four unit. Fitted with a closer ratio manual gearbox and lower ratio final drive, the acceleration was improved. Minor changes include more padding in the seats, headlamp covers, rear spoiler, cross drilled brake discs, alloy window winders and a six-spoke wheels. The rear wheels being slightly wider than before necessitated the fitting of "spats" on the back of the rear wheel arches to comply with EU regulations. The 111S was also fitted with a "chipcutter" front grille. In 2000, the 340R limited edition model, based on a Series 1 Elise was introduced. This roofless car was a special edition, limited to only 340 cars being built. The name 340 originally referred to the 340 bhp/tonne (254 kW/tonne) power-to-weight ratio of the original prototype which had while weighing just . However, in production models the 340 refers to the number of cars built. The final production versions weighed and had a power-to-weight ratio of /tonne. A "Track Pack" was created that upped power to and weighed only , thus fulfilling its original power-to-weight ratio promise. In 2000, Lotus introduced the Exige — a hardtop version of the Elise with the engine from the 340R; as well as different front and rear body "clamshells", larger wheels, and a rear wing. Many models received an upgrade to with better driveability due to changes to ECU and cam timing. The Series 1 could not be produced beyond the 2000 model production year due to new European crash sustainability regulations, so Lotus needed a development partner to meet the investment requirement for a Series 2 car. General Motors offered to fund the project, in return for a badged and GM-engined version of the car for their European brands, Opel and Vauxhall. The Series 2 Elise, announced on 9 October 2000, was a redesigned Series 1 using a slightly modified version of the Series 1 chassis to meet the new regulations, and the same K-series engine with a brand new Lotus-developed ECU.