Built on the Dodge Sprinter chassis, a platform with a proven track record in Europe, Winnebago's all-new Class C motorhome was created specifically for the American market. The Itasca Navion uses a Mercedes-Benz 2.7-liter turbocharged I-5 that develops 154 horsepower and 243 pound-feet of torque. For 1500 miles, we put the Itasca Navion through its paces. In steady operation across the Mojave Desert at 75 mph, with the dash A/C on high, we averaged a respectable 14 mpg. While that's not bad, the Navion specs list the vehicle's fuel economy at 17-19 mpg.
Climbing 10,000-foot-high mountain passes, the Navion was just as responsive at these elevations as at sea level, thanks to the diesel's turbocharger. While a gasoline engine loses about three percent of its power with each 1000 feet of elevation gain, the turbo-diesel isn't affected because of its higher compression ratio and pull-feed airflow.
If you plan to tow, the Sprinter platform has an adequate (but not impressive) towing capacity of 3500 pounds. GVWR is 10,200 pounds. With a full fuel tank, fresh water, LPG, two passengers, and personal gear on board, the actual gross weight of the unit was 9820 pounds, which means cargo-carrying capacity is less than 400 pounds. Plan--and pack--carefully.
When parked next to a standard American-built Class C motorhome (built on a Ford or GM chassis), the Navion is significantly smaller; however, by utilizing clever design choices, Winnebago has done a good job of gleaning maximum liveability out of the Navion's smaller size. The interior ceiling height is an impressive six feet eight inches, and the living area features a slideout seating arrangement. Navions feature a full bath and galley and sleep three adults.
On the road, the independent front suspension yields solid comfort, good cornering, and stability. The cockpit isn't as cushy as those in some Ford or GM Class C motorhomes, but it's functional. Side and rear coach visibility are good. And, thanks to electronically controlled fuel injection and a high-pressure single-rail fuel-delivery system, diesel noise is quieter than expected.
The automatic transmission is a Mercedes-Benz five-speed. To downshift, tap the shifter to the left, and the transmission shifts to the next lower gear. Bump the shifter to the right, and the transmission upshifts.
The Germans (this chassis comes from Dusseldorf) do interesting things when it comes to using mechanical seat-adjustment mechanisms. Once you learn the right combination of lever pulls, you can move the seats up, down, fore, and aft, and can tilt the seat bottom. These manual releases also allow the seatback to reclined. Electric seats aren't an option from the factory. The Navion's 24-foot length and 7.5-foot width make navigating through urban settings easy--but this convenience comes at a price. Base Navion models start at $78,872, while our test unit, with quite a few of the extras, was priced at $85,518.
About Diesel Motorhomes
Born Free--6.0-liter Power Stroke V-8
Doug Spencer, CEO of Dodgen Industries, told Truck Trend that before the 6.0-liter Power Stroke's introduction, four percent of all of Born Free's motorhomes were ordered with a diesel engine. Since that engine was brought to market, though, the figure has jumped to 20 percent. The diesel option adds about $5600 to the price, but customers want it for its durability. Over the long haul, the diesel engine, Spencer says, offers three to five mpg better fuel economy, plus the engine has greater longevity.
Conquest Super C--6.6-liter Duramax V-8
Introduced two years ago, the Super C (built on GM's Kodiak platform) is offered with the Duramax. The option costs about $20,000, but includes more than the engine. The package comes with an exhaust brake, a diesel-powered 5.5 auxiliary generator, aluminum wheels, and a 22,000-pound GVWR.
Steve Lidy, director of marketing at , says approximately 40 percent of the motorhome enthusiasts who buy the Super C are choosing diesel.
Beginning January 1, 2007, nitrogen oxides and particulates must be reduced from 2004 levels (the current standard) by 90 percent. Allen Schaeffer (executive director, Diesel Technology Forum) says this can be achieved in a couple of ways. First, the sulfur content of diesel fuel will be reduced from 500 parts per million (ppm) down to 15 ppm. Second, exhaust filters or soot traps likely will be in all diesel exhaust systems.
But the year 2010 is the real milestone. Based on today's emissions standards, all nitrogen oxides and particulates must be 98 percent cleaner than the mandated levels are today. Bottom line: By 2010, diesel exhaust will be as clean as gasoline exhaust. Possible new technologies to achieve these reductions include the use of urea, which is injected into the exhaust stream, and new generations of catalytic converters.