Vehicles

A No-Sweat Stretch for the Navigator

LCT staff
Posted on January 1, 2003

As the few remaining really large sedans get lower and lower, and correspondingly harder and harder to enter and exit, operators and coach builders are turning to luxury SUVs as the basis for limousines. It was probably no more than a week after Lincoln launched the Navigator luxury SUV that the first coach-builder stretched one into a limo that both made a statement and was comfortable for a large group of riders.

The fly in the ointment for the coachbuilders was Ford Motor Co., the donor vehicle manufacturer. Cut the frame, and it cut the warranty. Still, Ford knew that the statement mad by a stretched Navigator would be good for them as well, and they wanted to have a vehicle for the coachbuilders which would pass the FMVSS standards.

The final items won’t come together until early in 2003, but as the vehicle on the cover shows, prototypes have already been built and the full testing regimen is underway on a factory-certified, 140-inch stretch on the Navigator.

Bus Rules

LCT spoke with Terry Dewey, the engineer at Ford overseeing the project. “Our research showed that wedding parties and graduation parties seemed to center on 14 people. We had originally decided to work on a 120-inch stretch, but the 14-passenger, plus driver, requirement took it up to 140-inches,” Dewey said.

He noted that even at the 12-passenger requirement, the vehicle went from being a passenger car to a bus, by federal standards. The goal of the engineers is to have it meet both the passenger car and the bus federal safety standards.

The 14-passenger capacity means the vehicle must have a Gross Vehicle Weight Rating (GVWR) of 10,000 lbs. Suspension, brakes, wheels and tires all have to work to this requirement.

A Work In Progress

As this written, final testing is being performed on brakes and suspension. As an internal requirement, Dewey noted that the company wanted to retain the air suspension that differentiates the Navigator platform from from its first cousin, the Expedition. The brake tests have resulted in the fitting of larger rotors and larger pads to the brakes, while the suspension testing seems to indicate that the air suspension will be up to the weight requirements with the fitting of a larger air pump.

LCT asked Dewey about wheels and tires for the increased weight. He answered that the optional 180inch wheels on the consumer vehicle are more than adequate, but sturdier tires are being specified for the 140-inch stretch models.

The final crash testing will be done with the two prototype vehicles. One can be used for both the front and rear straight-on tests, while the other can be used for the offset crash test. It may seem a shame and a waste to crunch two completed vehicles, but the feds require it, and the result will be that the ones actually built for sale will be safer.

Starting from Stock

LCT asked Dewey how, if at all, a Navigator ordered by a coachbuilder for a stretch, would differ from a Navigator sold to a retail customer. “It is almost the same,” he replied. The coachbuilder orders a “Limo Builder’s Package,” Dewey explained that the vehicle is marked in the VIN as having the package, so that it can identified later on. “They’ll have to order the stretch chassis parts separately, but the base chassis will come with the upgrades to handle the extra load. There will be one builder’s package for everything up to the 140-inch stretch.”

Related Topics: Ford, Lincoln Navigator

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