Ford's engineering team has started its quest to implement revised fuel-saving modifications to its truck and SUV lineups and has revealed its latest touched-up model, the 2009 Lincoln Navigator 4x2, with an improved fuel mileage of 14 mpg city and 20 mpg highway.
Prior to what Ford calls "architectural and engineering enhancements" for the 2009 vehicle, the 2008 Navigator with the same 5.4L Triton V-8 achieved an EPA fuel rating of 12 mpg city and 18 mpg highway. Key to bumping up the figures was the use of a revised six-speed transmission that employs wider gear ratios. Tuning to the truck's ECU lowers engine idling speeds and reduces excessive fuel usage.
Also utilized by the Ford engineers is a unique software that regulates gas consumption through a fuel shutoff system. Once deceleration occurs, the system quickly cuts fuel flow and regulates the critical air-fuel mixture to the engine.
"Deceleration is when you take your foot off the accelerator and you're coasting and the system very aggressively shuts fuel off," says John Rich, powertrain integration and program manager for Ford Trucks. "It sounds simple, but it's not at all simple. To make this work, we had to carefully manage the complex and constantly changing air-fuel mixture caused by aggressively shutting off fuel flow."
Ford's fuel-shutoff system is expected to be implemented on most of the brand's future trucks and SUVs, including the upcoming redesigned 2009 Ford F-150.
Source: Ford