RV Classroom

The explosive growth in RV chassis innovations has introduced a new dynamic to the selection process for your next RV.

There was a time when RVers would simply accept the chassis and engine the manufacturers provided with their motor homes. Very little consideration was given to the platform that the vehicle was built on because there were only a few RV chassis products available.

How To Choose The Best Chassis For You

How To Choose The Best Chassis For You

However, over the past five years the industry has seen a dramatic increase in the number of proprietary and customized RV chassis offerings being developed in concert with the RV manufacturers. What was once a given, is no more! Educated RVers are now looking very closely at the chassis and engine offerings and are studying the differences that will eventually determine their satisfaction with respect to the level of comfort, performance and maneuverability they are going to expect from their RV investment.

ROADMASTER CHASSIS, MONACO COACH CORPORATION
Roadmaster Chassis, a division of Monaco Coach Corporation, does only one thing – it builds the chassis for Monaco’s family of product lines. Each chassis is engineered to the exact specifications that will provide the safety, reliability and performance required by the RV model that will be built on it. Products in the Monaco, Holiday Rambler, Beaver and Safari product lines are built on one of seven Roadmaster Chassis platforms.

Their flagship RV chassis is the S-Series and depending on the model and floor plan, you may find your rig powered by a Cummins® ISL 425 hp engine with 1200 ft-lbs of torque at 1300 r.p.m. mated with an Allison® 3000 MH 6-speed transmission, a Detroit Diesel Series 60 engine offering 515 hp with 1650 ft-lbs of torque at 1200 r.p.m. coupled with an Allison 4000 MH 6-speed transmission, or a Cummins ISX 525 hp engine that also delivers 1650 ft-lbs of torque at 1200 r.p.m. and accompanies an Allison 4000 MH transmission.

Roadmaster Chassis products include cushion air-glide suspension that enables the left and right sides of the suspension to operate independently of each other. This provides the benefits of independent suspension without the complexity, cost and higher maintenance associated with conventional independent front suspension. Roadmaster Chassis is also known for its outboard mounted air bags that are placed approximately seven and a half feet apart on most models, providing a wider and more stable platform. The active suspension automatically adjusts the pressure of the air bags as you drive and virtually eliminates nose-diving and the side-to-side body sway associated with high wind conditions, curvy roads and emergency maneuvers. The power steering box on all Roadmaster chassis provides a 50-degree front wheel cut in both directions for easier maneuverability.

EVOLUTION CHASSIS, WINNEBAGO INDUSTRIES
The Winnebago engineers in Forest City, Iowa worked closely with Freightliner to design the Evolution chassis, an exclusive Winnebago Industries RV chassis. Its unique design features one-piece, precision-formed chassis rails that provide increased center section clearance that has resulted in an impressive amount of basement storage without compromising the strength and integrity of the chassis. The Evolution allows for greater design flexibility, as evidenced in the three 40’ floorplans being offered this year, especially the exciting 40TD with a huge front kitchen on the passenger side that flows smoothly into the dining and living room area. A large bathroom, accessible from the living room and master bedroom suite, makes this a very popular motor home. These floor plans are a perfect example of the outstanding results of design creativity matching consumer desired functionality.

The standard configuration is the Evolution chassis with a Caterpillar 7.2L turbo-charged 350 hp diesel engine, rear radiator, Allison 3000 MH 6-speed electronic transmission, NeWay front & rear air suspension, 160-amp alternator, 4-wheel ABS and exhaust brake. To meet the consumer demands for power, performance and great road manners you can upgrade to the Cummins engine configuration.

Also available on the Winnebago models is the new Maxum drop rail RV chassis which is a maximum strength chassis that provides an impressive 220 cubic foot cargo area.

LIBERTY CHASSIS, AMERICAN COACH
American Coach and Spartan have created the Liberty Chassis, which is the exclusive platform for American Coach models. The 40’ and 42’ units are configured with a Cummins 400 hp engine however the 42’ models can be ordered with the Cummins 500 hp or CAT 525 hp power plants. The 45’ models can be configured with a 500 hp Cummins or 525 hp CAT® matched with an Allison 4000 MH transmission. These units also offer 200 amp service to meet all of your home-on-wheels requirements

While many of the larger motor homes offer 10,000 lb. towing capacity, the Liberty Chassis offers a huge 15,000 lb. capacity so you can tow all of your favorite toys behind. Its 55-degree wheel cut and independent front suspension will allow you to efficiently maneuver smoothly and sharply through city traffic or tight quarters. The all-steel structure minimizes flex and contributes to a lower center of gravity which enhances the driving experience. Laminated storage liners that are made of a durable fiberglass-reinforced plastic along with an electro-coated structure will protect your investment against corrosion for many years to come.

DYNOMAX CHASSIS, COUNTRY COACH
Country Coach, a privately held company under the direction of Bob Lee and Jay Howard, is another quality manufacturer that builds luxury motor coaches from 34’ to 45’ and all of them are built on their proprietary DynoMax® chassis.

The hallmark features of the DynoMax chassis include 100% steel construction with no aluminum or wood framing. It offers independent front suspension with double wishbone construction, large bus-style air springs, ABS disc brakes and an IPD anti-sway bar. You will appreciate the dual fill fuel tank and cavernous, unobstructed pass-through basement storage compartments as you cruise down the highway on steel-belted radial tires and aluminum alloy wheels, protected by Koni heavy duty shock absorbers. Each RV chassis is designed to provide plenty of power to take on the most challenging mountain grades and is coupled with superior chassis performance features that offer excellent steering, acceleration, shock absorption, braking and high weight ratings.

The Country Coach models are destined for greatness with their stunning curb appeal and numerous features that leave nothing to the imagination in the world of luxury motor coaches today. Some of these vehicles will easily win over bus conversion aficionados when they jump into the cockpit and fire up the Caterpillar 625 hp C15 engine, delivering an incredible 2,050 ft. lbs. of torque, which is finely tuned and expertly matched to the Caterpillar CX-Series 6-speed transmission. Others are powered by a Caterpillar C9 400 hp, Caterpillar C9 8.8L 400 hp, or Cummins 400 ISL engine paired with an Allison 300 MH transmission. Select models can also be ordered with a Cummins 425 ISL engine that delivers 1200 ft. lbs. of torque at 1300 r.p.m., or for maximum power, a Cummins ISX 600 hp engine that delivers 1850 ft. lbs. of torque at 1400 r.p.m..coupled with an Allison 4000 MH transmission.

As you can see, there are a host of options and features that each manufacturer has incorporated into the design of their RV chassis products and the integration of that creation into an outstanding motor home that will deliver many years of pleasure and enjoyment to your RVing experience. Do your research before you buy and be sure to test drive the models of interest in order to evaluate the handling, acceleration, braking, turning radius, passing performance, noise suppression and overall comfort of your next motor home to be sure it is the best one for you.

Front or Rear, Gas or Diesel?

At the risk of totally confusing many of our readers, we would be remiss if we did not touch on the new developments that continue to be introduced by the industry’s leading RV chassis manufacturers. Freightliner has introduced the FRED chassis which is a unique front engine design that brings the diesel engine over the front wheels.

This chassis is powered by a 300hp Cummins 5.9L ISB diesel engine with 600 ft. lbs. of torque and has a 26,000 pound GVWR and a 30,000 pound GCWR. The FRED chassis has a 55-degree wheel cut and an impressive flat floor design which enhances the comfortability of the cockpit area.

Workhorse Custom Chassis continues to showcase engineering excellence with their new UFO (Universal Floorplan Option) chassis. The UFO provides manufacturers with the option of a rear engine gas or diesel configuration that provides added flexibility in floor plan design and carrying capacities. With the rear engine gas option one can enjoy many diesel-like features.

Some of the advantages of a rear engine motor home include less cabin noise, less cabin heat, and without the front-to-back drive shaft, less vibration as well as the ability to build in pass-through basement storage compartments. A rear engine gas RV chassis also allows the engineers to incorporate a front entry door and additional slideouts into their floor plans.

Ultra Low Sulfur Diesel

The technology that drives the country’s trucking industry also impacts the engineering of products specifically designed for RVs. The most current technological impact was the introduction of the Ultra Low Sulfur Diesel engines that started arriving in new motor homes this year. Often referred to as ULSD, ultra low sulfur diesel is a requirement established by the government that mandates that all new diesel engines shipped after January 1, 2007 use this new fuel.

Fuel that meets the ULSD fuel specifications will allow your diesel engine to operate your new motor home more efficiently as well as contribute to a greener environment. Under these new regulations, at least 80% of highway diesel fuel produced must have only 15 ppm (parts per million) sulfur by mid-2006 versus the 500 ppm sulfur fuel produced up until that time. The new formula is designed to reduce emissions and particulates to achieve the same emissions standards as gasoline vehicles.

Some service stations, including Flying J, have already begun changing over to ULSD and effective December 1, 2010 all service stations will be required to carry ULSD fuel. It is estimated that there could be a 1% reduction in fuel economy attributed to the new ULSD fuel and there should be no noticeable impact on power.

RVers will have to be careful when refueling at gas stations and truck stops that still sell the diesel fuels used by many of the older trucks on our nation’s highways. Putting the wrong diesel fuel into your new ULSD engine (referred to as misfueling) can damage the exhaust after-treatment system incorporated into these new engines. However, engines that were sold prior to January 1, 2007 can, and SHOULD, use the new ULSD fuel which will be distinguished on each diesel pump.

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