the four-wheel drive (4WD) versions. The previous generation had full-time connected front axles. The improvement saves fuel and by default goes into a wheel-locked position. Should a failure occur in the vacuum solenoid, system, or hoses, the wheel hub defaults to a 4WD position to keep from leaving a driver stranded. Internally, a three-valve version of the 5.4 L V8 was introduced and replaced the previous two-valve version. Externally, the 11th-generation model was different from its predecessor, with sharper-edged styling; a major change was the adoption of the stepped driver's window from the Super Duty trucks. Regardless of cab type, all F-150s were given four doors, with the rear doors on the regular cab providing access to behind-the-seat storage. Ford also introduced additional variants of the F-150. The FX4 Off-Road package available since the 2002 model year became its own trim level. A sportier version of the F-150 became available as STX, replaced by FX2 Sport in 2007. From 2005 to 2008, Lincoln-Mercury dealers sold this version of the F-150 as the Lincoln Mark LT, replacing the Blackwood. In late 2007 for the 2008 model year, the Super Duty trucks were given an all-new platform. While using the same bed and cabin as before, these are distinguished from their predecessors by an all-new interior and a much larger grille and head lamps. Previously available only as a chassis-cab model, the F-450 now was available as a pickup directly from Ford. Twelfth generation (2009–2014) The 12th-generation F-150 was introduced for the 2009 model year as an update of the Ford full-sized truck platform. Similar to its predecessor, these trucks are distinguished by their Super Duty-style grilles and Edge-style headlights; standard-cab models again have two doors instead of four. The Flareside bed was continued until 2010, dropped along with the manual gearbox; outside of Mexico, the Lincoln Mark LT was replaced by the F-150 Platinum. A new model for 2010 included the SVT Raptor, a dedicated off-road pickup. In 2010, Ford shifted its electronics from a general electric module base to the computerized and programmable body control module, allowing for fewer parts differences and programmable upgrade options from the dealer or factory. In 2011, Ford reintroduced the 5.0 in the F-Series with its new 5.0 Coyote dual overhead cam TiVVT engine with 360 hp. As part of a major focus on fuel economy, the entire engine lineup for the F-150 was updated