a separate, but integrated body and frame (IBF) structure. The fourth iteration, as of 2009 – like the series II, was again mainly an update of the new generation – marketed as the Discovery 4, or Land Rover LR4 for North American and Middle Eastern markets. The fifth iteration of the Discovery, introduced in 2017, no longer sports a numeric suffix. Unlike the previous two generations, it now benefits from a unitized body structure, making it lighter than its predecessor. First generation Discovery Series I (1989–1998) The Discovery Series I was conspicuously presented during the 1989 Frankfurt Motor Show and introduced to market in the United Kingdom in October that year, after the vehicle had been developed under the internal code-name "Project Jay". The new model was strongly based on the more upmarket Range Rover, using the same chassis, suspension and 4WD-system, and a derivative body design – especially the four-door copied much of the more expensive Range Rover's body structure. However, with smaller engines available, just two side doors at introduction, and other cost-reductions, the new Discovery was priced more affordably, for a larger, more middle-class market segment, intended to counter the Japanese competition at the time. The Discovery was Land Rover's first model that was positioned as a family car, designed to be both fully off-road capable and suitable as a daily driver for any family, even offering more luggage space and optionally more seats than the Range Rover. The Mark I Discovery remains the only model offered as a three-door, and was the only one available with a four-cylinder petrol engine until 2017. At launch, the Discovery was only available as a three-door model; the original 64 units sold in the first year (with G-WAC number plates) are increasingly prized. The five-door version followed in 1990. Both were fitted with five seats, with the option to have two jump seats fitted in the boot. Compared to the Range Rover, the Discovery was given a slightly longer rear which was further extended on the series II. In order to make room for optional third row jump seats, the spare wheel had to move to the outside of the car, fitted to a side-swinging rear door, instead of the Range Rover's split tailgate. The roof of the rear section of the car was raised, to create sufficient headroom in the third row. Combined with a safari side window cluster,