Called the W22D and W20D, the 22,000 and 20,500 lb. GVWR diesel-powered chassis will now give RV buyers more new choices for the platforms that have become known for their exceptional ride, handling and performance. The W20D made its debut at the National RV Trade Show in Louisville this week. Two major motor home manufacturers also displayed models built on the W20D: the Itasca Sunstar and the all-new Four Winds Serrano, both with floorplans in the 32-foot range.
This evolution of the groundbreaking W20/W22 gas platforms marks the latest appearance of a Navistar MaxxForce engine on the motor home scene. This time it’s the MaxxForce™ 7, a 230 horsepower 6.4L V8 powerplant that puts out a hefty 620 lb.-ft. of torque to provide exceptional pulling power while achieving superior performance, reliability and fuel economy. Navistar also touts the MaxxForce 7 as a quiet diesel designed to greatly reduce the noise and vibration of the engine, providing an exceptional driving experience for the RV owner. Couple the MaxxForce 7 with the six-speed Allison transmission and the RV owner will experience a new level of driving ease.
The turbo with charge-air cooler is tuned to reduce noise, improve fuel economy and make MaxxForce 7-powered vehicles responsive and easier to drive. The MaxxForce 7 will provide a True Diesel™ emissions solution for 2010 that uses only diesel fuel, not both diesel and urea as required by SCR emissions control. Instead, advanced EGR and proprietary “In-Cylinder’ technology is used to meet 2010 emissions standards without additional after-treatment or negative impact on fuel economy.
“In today’s economic environment, product differentiation becomes even more critical to manufacturers,” said Workhorse Vice President of Marketing and Product Planning Tony Monda. “Navistar’s MaxxForce™ engines provide a one-two punch — differentiation and fuel economy. Even though prices have dropped recently, consumers are very sensitive to the issue.”
“The W20 and W22 are our most popular chassis. People love the maneuverability that comes with their 50-degree wheel cut along with the stable, comfortable ride these platforms provide. Now they also have the power and efficiency of the MaxxForce™ engine. This advancement brings diesel benefits well into the price range of the smaller gasoline coaches that are becoming more prominent.”
Both Workhorse and MaxxForce are affiliates of Navistar, “These new platforms typify the benefits of the great synergy we are developing within Navistar,” said Monda. “With this excellent engine now married to some of our most well-received chassis, the RV market is beginning to see some exciting new product developments.”
Service on the W20D and W22D chassis can be performed at more than 500 Workhorse Service Centers across the U.S. and Canada, while the MaxxForce engine will be serviced at RV participating International Truck and Engine Service dealers.

Nikki is a writer and editor for Do It Yourself RV, RV LIFE, and Camper Report. She is based on the Oregon Coast and has traveled all over the Pacific Northwest.
I live in Australia and have the pleasure off owning. A 2010 seranio motor home. I’m hoping I can buy a parts no book for the w20 6;4 v8 deisal motor as I am in need off parts my email is beamernominees@ big pond.com