At least 10 manufacturers produce diesel-powered type A chassis for motorhome builders.
By Jim Brightly
As noted in last month’s “Type A Chassis: The Gas Pullers” story, only two manufacturers build gas-powered chassis for type A motorhomes today. At least 10 manufacturers are vying for the consumer’s diesel dollar. Of the 10 companies, seven produce chassis strictly for in-house motorhome production. Freightliner, Spartan, and Workhorse, on the other hand, focus on chassis production and supply their chassis to motorhome manufacturers.
While consumers have a limited say as to which chassis is used for the motorhome they wish to purchase, it is important that they know what types of chassis are available so they can make better choices when shopping for a motorhome. Perhaps the deciding factor between buying a new coach from company A or company B is the type of suspension used, or the horsepower rating of the engine.
In this article, we list only those manufacturers that produce type A diesel-pusher chassis; bus chassis are not included. Here are the 10 manufacturers in alphabetical order by company name.
Blue Bird Corporation
Blue Bird, C4, is one of the companies that builds chassis specifically for its own motorhomes. The Blue Bird chassis is pushed along by a Cummins ISL 400-horsepower engine (1,250 pound-feet torque at 1,300 rpm) mated to an Allison 3000 MH electronic six-speed transmission. Both are controlled by an electronic accelerator and transmission computer connection that links the two components together for precise shifting and rpm control. The chassis is equipped with a 145-gallon fuel tank.
The chassis used for Blue Bird’s 38-foot Wanderlodge M380 has a 248-inch wheelbase. Yet, even with a coach of this length, the chassis’ 54-degree turning angle allows drivers a comfortable curb turning radius of 29.7 feet and a wall turning radius of 35 feet.
The Blue Bird chassis is equipped with an ArvinMeritor suspension that includes an independent front suspension with two air bags and a rear system that utilizes four outboard air bags. Gabriel direct-acting, double-action, piston-type shock absorbers soften the ride on all four corners. The chassis is equipped with Meritor disc brakes on all four corners with a Bendix four-channel antilock braking system (ABS).
With a gross vehicle weight rating (GVWR) of 36,100 pounds and a gross combination weight rating (GCWR) of 46,100 pounds, the Wanderlodge can accommodate an estimated one ton of cargo and pull almost any size towed vehicle. Chassis of a similar design with a tag axle and GVWR of 52,000 pounds and a GCWR of 70,500 pounds will be used on Blue Bird’s M400 and M450 motorhomes, which will replace the LX and LXi; the new models are scheduled to be available in the spring of 2004.
Blue Bird Corporation, One Wanderlodge Way, Fort Valley, GA 31030; (478) 822-2400; www.blue-bird.com.
Country Coach Inc.
The DynoMax chassis is built by Country Coach Inc., C2132, for all of its motorhome models. The DynoMax features a semi-monocoque cage design. High-grade steel tubing is welded, not bolted, to the frame, which is said to strengthen the entire unit.
The chassis is equipped with a variety of engine and transmission combinations, each used for particular Country Coach motorhomes. The chassis for the Inspire is equipped with a Cummins ISC 350-horsepower engine (1,050 pound-feet torque at 1,400 rpm), along with an Allison 3000 MH six-speed electronic transmission. The chassis used for the Allure is equipped with the 370-horsepower Cummins ISL engine while the Intrigue uses the 400-horsepower ISL engine (both with 1,200 pound-feet torque at 1,300 rpm), and each are mated to the Allison 3000 MH transmission. The Intrigue also is available with the optional 505-horsepower Caterpillar C-12 engine (1,550 pound-feet torque at 1,200 rpm). The Magna, Affinity, and Lexa chassis are equipped with Caterpillar’s C-15 515-horsepower engines (1,650 pound-feet torque at 1,200 rpm) mated with the Allison 4000 MH six-speed electronic transmission.
In December 2003, the first DynoMax chassis using the new Caterpillar C-13 ACERT (Advanced Combustion Emission Reduction Technology) engine will be introduced. With 525 horsepower and 1,650 pound-feet torque at 1,200 rpm, this engine represents a new generation of air system management and engine electronics that is intended to provide a long-term solution for clean air regulation.
Weight ratings for the DynoMax chassis range from 33,800 pounds GVWR and 43,800 pounds GCWR in the case of the Inspire to 49,500 pounds GVWR and 56,500 pounds GCWR for the Lexa. Fuel tank sizes range from 110 gallons to 164 gallons, and all can be filled from either side of the motorhome.
The DynoMax chassis is equipped with a dual-circuit pneumatic braking system, with both antilock and automatic traction control systems. An engine exhaust brake is included with the Cummins ISC engine, while a Jacobs compression brake is used for the Cummins ISL and all Caterpillar engines.
The chassis features air springs at each wheel, which work with the chassis’ leveling system. In addition, a large ipd antisway bar minimizes side-to-side rolling while allowing the independent front suspension to travel freely. During and after construction, each chassis is sent to Country Coach’s DynoCenter where the alignment and braking systems are tested.
Country Coach Inc., 210 E. Sixth Ave., Junction City, OR 97448; (800) 654-0223; www.countrycoach.com.
Fleetwood American Coach
The Liberty chassis is a new foundation that is being used for all of Fleetwood’s 2004-model American Coach motorhomes. Fleetwood, C985, does not offer the chassis to other motorhome builders.
The Liberty uses a bridge-type frame that is said to provide the torsional strength needed to accommodate the weight and wall penetrations required for motorhomes with two, three, and four slideouts. Welded tubular steel members create the bridge portion of the chassis, while a process called Huck-bolting is used to attach the bridge to the rear frame rails that hold the engine, transmission, and the rear axle and its suspension components. Huck-bolting also is used to attach the front rails where the steering gear and the front axle and its suspension are connected. To fight corrosion, a military-spec electro-coating process is applied to the Liberty chassis frame.
Three Cummins engines are used to power the chassis, which has a GVWR of 34,600 pounds (44,600 pounds on the 42-foot tag axle model) and GCWRs of 46,600 pounds or 49,600 pounds (59,600 pounds on the tag axle model). The engines used are the 370-horsepower and the 400-horsepower ISL (both generating 1,200 pound-feet torque at 1,300 rpm), each mated to an Allison 3000 MH six-speed automatic transmission, and the 500-horsepower ISM (1,550 pound-feet torque at 1,200 rpm), which uses Allison’s 4000 MH six-speed automatic transmission. The Liberty has a 125-gallon fuel tank that can be filled from both sides of the motorhome.
Fleetwood Enterprises Inc., 3125 Myers St., Riverside, CA 92513-7638; (800) 444-4905; www.fleetwoodrv.com
Foretravel Inc., C236, manufactures two chassis that it uses on its production motorhomes. One chassis is used for U270 and U295 models, and the other is used on the U320 model. Although they are different, each has many similar features.
Those similarities include dual fuel fills (one on each side) for the 180-gallon fuel tank; a Firestone air bag suspension system (eight air bags on the U270 and U295 models; 10 air bags on the U320 model, which is equipped with a tag axle); and all-wheel air disc brakes with ABS.
Now we’ll get into the differences. The platform used for the U270/U295 models is powered by the 400-horsepower Cummins ISL (1,200 pound-feet torque at 1,300 rpm), which is mated to an Allison 3000 MH transmission. The chassis has a 35,320-pound GVWR and a 45,320-pound GCWR and is available with wheelbase lengths of 204 inches, 228 inches, 252 inches, and 276 inches.
The U320 model is equipped with a Cummins ISM 450-horsepower engine (1,450 pound-feet torque at 1,200 rpm) with an Allison 4000 MH transmission. Later model-year coaches may be outfitted with a Cummins 500-horsepower engine. It has weight ratings of 42,000 pounds GVWR and 52,000 pounds GCWR. This chassis, which includes a tag axle, is available in wheelbase lengths of 278 inches, 302 inches, and 326 inches.
Foretravel Motorhomes Inc., 1221 N.W. Stallings Drive, Nacogdoches, TX 75964; (800) 955-6226; www.foretravel.com.
Freightliner Custom Chassis Corporation
Freightliner, C1905, offers the XC Series diesel-pusher chassis for motorhome applications, which is available with several engine and transmission combinations. Choices include the 300-horsepower Cummins ISB (two versions: 600 and 660 pound-feet torque at 1,600 rpm); the 350-horsepower Cummins ISC (1,050 pound-feet torque at 1,400 rpm); the 370 horsepower or 400 horsepower Cummins ISL (each with 1,200 pound-feet torque at 1,300 rpm); or the Caterpillar 3126E with power ratings of 300 horsepower or 330 horsepower (860 pound-feet torque at 1,440 rpm). The XC chassis features the Allison 3000 MH six-speed transmission with all engines except the ISB 300-horsepower engine with 600 pound-feet torque, which uses the Allison 2000 MH five-speed transmission.
Wheelbase lengths run the gamut, with a dozen choices ranging from 190 inches to 276 inches. The GVWR ranges from 26,850 pounds to 32,880 pounds, and the GCWR ranges from 36,850 pounds to 42,880 pounds.
The XC Series frame is constructed using a combination straight and raised-rail design and carries either a 90-gallon, 100-gallon, or 150-gallon fuel tank that can be filled from either side of the motorhome. Neway air suspensions support the front and rear of the chassis, which also incorporates custom-tuned Sachs shocks. The XC chassis is equipped with air brakes (drum) and ABS. A drum-style, spring-applied, air-released parking brake is used on the rear axle. Steering is hydraulically assisted with a 20.4:1 ratio and a 50-degree cut angle. The new optional ZF independent front suspension features air disc brakes with ABS and a 56-degree wheel cut angle.
Freightliner Custom Chassis Corp., 552 Hyatt St., Gaffney, SC 29341; (864) 487-1700; www.freightlinerchassis.com.
Monaco Coach Corporation
Roadmaster is the exclusive diesel chassis division for all of Monaco Coach Corporation’s motorhome manufacturing companies. Currently, its lineup includes four chassis series: the R-Series; the RR-Series; the M-Series; and the S-Series. Each series may also include several variations of the basic chassis, depending on the number of air bags and shocks included, and the positioning of the radiator (either side or rear). For instance, the RR4S chassis is designed on a raised-rail frame (RR) with four air bags and four shocks (4), and a side-mounted radiator (S).
All Roadmaster chassis share several common features. First, each uses the company’s Cushion Air-Glide suspension system, which is said to deliver superior ride, effortless handling, and excellent roll stability. And each chassis’ fuel tank can be filled from either side of the motorhome.
The R-Series includes the R4R, which is a straight-rail frame chassis that uses the Cummins ISB 300-horsepower engine (600 pound-feet torque at 1,600 rpm) and an Allison 2000 MH five-speed transmission with a push-button shift pad. This chassis is used for the Monaco Cayman and the Holiday Rambler Neptune. The chassis includes hydraulic brakes with ABS and is equipped with a 75-gallon fuel tank.
The R4R is available in three wheelbase lengths “” 188 inches, 204 inches, and 228 inches “” and has a GVWR of 24,000 pounds and a GCWR of 28,000 pounds.
The RR-Series includes the RR4R (Holiday Rambler Ambassador, Monaco Knight, and Safari Cheetah and Sahara); the RR4S (Safari Zanzibar); the RR8R (Beaver Santiam, Holiday Rambler Endeavor, and Monaco Diplomat); and the RR8S (Holiday Rambler Imperial and Scepter and Monaco Camelot and Windsor).
Available engines include the 330-horsepower Cummins ISC (950 pound-feet torque at 1,400 rpm) that is used on the Ambassador, Diplomat, Endeavor, Knight, and Santiam models; the 350-horsepower Cummins ISC (1,050 pound-feet torque at 1,400 rpm) used on the Scepter, Camelot, and Sahara models; the 370-horsepower Cummins ISL (1,200 pound-feet torque at 1,300 rpm) used on the Zanzibar; the 400-horsepower Cummins ISL (1,200 pound-feet torque at 1,300 rpm) used on the Imperial and Windsor models; and the 330-horsepower Caterpillar 3126E (860 pound-feet torque at 1,424 rpm) used on the Cheetah. All are mated to an Allison 3000 MH six-speed transmission with electronic shifter.
All RR-Series chassis include full air brakes (drum, except for the Windsor, which uses disc front brakes) with ABS and a Pacbrake exhaust brake, except for the Imperial and Windsor, which have an engine compression brake. These chassis also are equipped with automatic traction control and either a 90-gallon or 100-gallon fuel tank, except for the Windsor (127 gallons) and Imperial (128 gallons).
Wheelbase lengths range from 204 inches to 270 inches, and all but the RR8S chassis boast GVWRs of 32,000 and GCWRs of 42,000. Within the RR8S chassis, the Imperial and Windsor each have a 37,600-pound GVWR and a 47,600-pound GCWR; the Scepter has a GVWR of 33,000 pounds and a GCWR of 43,000 pounds; and the Camelot has a GVWR of 33,000 pounds and a GCWR of 43,000 pounds.
The M-Series includes the M8S (Beaver Monterey and 37-foot Patriot) and the M10S (Beaver Marquis and 40-foot Patriot). Power plants used in this series include the 350-horsepower Cummins ISC engine (1,050 pound-feet torque at 1,400 rpm), which is used for the Monterey; and the 400-horsepower Cummins ISL engine (1,200 pound-feet torque at 1,300 rpm) for the Patriot. Each are equipped with an Allison 3000 MH transmission. The Marquis employs the 505-horsepower Caterpillar C-12 engine (1,550 pound-feet torque at 1,200 rpm) with an Allison 4000 MH transmission.
All M Series chassis are equipped with full air brakes (drum on the Monterey; disc on the Patriot and Marquis) with ABS and automatic traction control. The Monterey includes a Pacbrake exhaust brake, while braking assistance for the Patriot and Marquis is provided by a Jacobs engine compression brake.
Wheelbase lengths range from 220 inches to 310 inches. The Monterey has a 32,800-pound GVWR and a 42,800-pound GCWR. The 37-foot Patriot has a 36,300-pound GVWR and a 46,300-pound GCWR, while the 40-foot Patriot models have a GVWR of 46,300 pounds and a GCWR of 56,300 pounds. The Marquis has a 46,300-pound GVWR and a 56,300-pound GCWR. Both the Patriot and Marquis have 148-gallon fuel tanks; the Monterey has a 109-gallon tank.
The S-Series chassis is used for the top-of-the-line motorhomes built by Monaco, Holiday Rambler, and Safari. This group includes Monaco’s Signature Series, Executive, and Dynasty coaches; the Holiday Rambler Navigator; and the Safari Panther.
The chassis on which the Executive, Signature, and Navigator are built use Cummins’ 500-horsepower ISM engine (1,550 pound-feet torque at 1,200 rpm). An optional engine for both the Signature and Navigator chassis is the 500-horsepower Detroit Diesel Series 60 (1,650 pound-feet torque at 1,200 rpm). The Signature even has a third engine option, the 525-horsepower Cummins ISX (1,650 pound-feet torque at 1,200 rpm). All feed their power through Allison’s 4000 MH six-speed transmission. The chassis used for the Panther is pushed by Caterpillar’s 505-horsepower C-12 engine (1,550 pound-feet torque at 1,200 rpm) along with the Allison 4000 MH transmission. The Dynasty chassis is equipped with Cummins’ 400-horsepower ISL engine (1,200 pound-feet torque at 1,300 rpm) and Allison’s 3000 MH six-speed transmission.
For braking power, all but the Signature utilize full air brakes “” disc-style in the front and drum in the rear “” with ABS. The Signature uses air disc brakes with ABS all around. The tag axle is equipped with ABS as well. All use a Jacobs engine compression brake for additional stopping power, and an automatic traction control system. Wheelbase lengths vary with each model and range from 226 inches to 285 inches. The weight ratings for all but the Dynasty are 47,600 pounds GVWR and 57,600 pounds GCWR. The Dynasty is rated at 44,600 pounds GVWR and 54,600 pounds GCWR. The fuel tank used on the Dynasty and Panther chassis has a 130-gallon capacity, while tanks used on the Executive, Signature, and Navigator hold 150 gallons.
Monaco Coach Corp., 91320 Coburg Industrial Way, Coburg, OR 97408; (800) 634-0855; www.monaco-online.com.
Newell Coach Corporation
Newell Coach Corporation, C47, has been at the forefront of diesel-pusher technology since L.K. Newell, the company’s founder, incorporated bus-type rear-engine diesel power into a motorhome chassis when he designed his pusher chassis in 1970.
Although continuously updated through the years, today’s Newell chassis incorporates the main features of the then-radical design created more than 30 years ago by Mr. Newell. To maximize underfloor storage, Newell created a chassis that utilized a bird-cage or bridge-type structure rather than conventional bulky frame rails. In addition to opening up the “basement” for storage, the structure achieved another goal of Mr. Newell’s: the chassis was self-supporting, not relying on the body sidewalls for strength. Little did Mr. Newell realize that, 25 years later, his innovative approach would continue to provide Newell motorhomes with an exceptionally rigid chassis that allows for up to four slideouts.
The standard chassis is powered by a Detroit Diesel Series 60 engine that generates 500 horsepower and 1,650 pound-feet of torque at 1,200 rpm. The engine is mated to an Allison 4000 MH transmission. The chassis is available in several wheelbase lengths, depending on the overall length of the coach (308 inches for the 45-foot model); has a 234-gallon fuel tank that fills on the driver’s side; and has a GVWR of 59,580 pounds and a GCWR of 73,580 pounds.
The Newell chassis rides on a ZF independent front suspension with air springs and wide-base air bags on the rear axle. The active steering system on the tag axle reduces the turning circle of the 45-foot chassis by approximately 15 feet compared to a chassis using a more conventional tag axle design. Air disc brakes with ABS are used all around, with a Jacobs engine compression brake for extra slowing power.
Newell Custom Coaches, P.O. Box 511, Miami, OK 74354; (888) 363-9355; www.newellcoach.com.
Spartan Chassis Inc.
Spartan Chassis Inc., C3322, entered the type A diesel-pusher chassis market in 1985. Spartan offers four different chassis to motorhome builders: the NVS/NVSGT, Mountain Master, K2, and Me2.
The company’s patented Spartan Active Ride system is available as an option on the Mountain Master and K2 chassis. Using a combination of hydraulics, electronic sensors, and computer controls, the system is said to provide a tight, level, and smooth ride for motorhomes. Spartan Active Ride gathers input from the four corners of the coach; integrates data on driving conditions, braking, speed, roll acceleration, and steering angle; and then adjusts each wheel end to smooth out the ride. The system’s microcomputers analyze this information 400 times every second to deliver the best response to extreme road conditions.
The NVS and NVSGT are Spartan’s entry-level diesel chassis. While they share many of the same features, there are several differences that set them apart from each other. The NVS chassis is built on a straight-rail frame with a Cummins ISB 300-horsepower engine (600 pound-feet torque at 1,500 rpm) and an Allison 2000 MH five-speed transmission. The NVS has a GVWR of 25,500 pounds.
The NVSGT chassis starts with a raised-rail frame with a 330-horsepower (950 pound-feet torque at 1,400 rpm) Cummins ISC engine mounted to an Allison 3000 MH six-speed transmission. This chassis has a 28,000-pound GVWR and a 38,000-pound GCWR.
The NVS/NVSGT chassis is available in wheelbase lengths of 208, 228, and 252 inches and comes with a 100-gallon fuel tank. It includes Spartan’s independent front suspension, a Reyco rear air suspension, and Bilstein shocks. All 2004 models now have a 55-degree steering cut angle. Stopping power is provided by full air brakes with ABS.
The Mountain Master GT is available in wheelbase lengths from 252 inches to 276 inches. The chassis is built on a stacked-rail frame and is powered by either the 330-horsepower Cummins ISC engine (950 pound-feet torque at 1,400 rpm) or one of two versions of the Cummins ISL engine: 370-horsepower or 400-horsepower (1,200 pound-feet torque at 1,300 rpm for both). An Allison 3000 MH electronic six-speed transmission is paired with these engines. The Mountain Master GT has a GVWR of 34,600 pounds and a GCWR of 49,600 pounds. It comes with a 100-gallon, 125-gallon, or 150-gallon fuel tank.
All 2004 Mountain Master GT models ride on Spartan’s independent front suspension system, a Reyco rear air suspension, with Bilstein shocks all around. The chassis has a steering cut angle of 55 degrees on a 14,600-pound-rated front axle, includes a front sway bar, and is equipped with full air brakes with ABS.
Spartan’s K2 chassis is built on a stacked-rail frame. The chassis receives its power from a 500-horsepower Cummins ISM engine (1,550 pound-feet torque at 1,200 rpm) connected to an Allison 4000 MH six-speed transmission. Wheelbase lengths available on the K2 range from 276 inches to 320 inches. The K2’s GVWR is 34,600 pounds and its GCWR is 49,600 pounds. An available tag axle boosts the GVWR to 44,600 pounds and the GCWR to 59,600 pounds. The chassis rides on Spartan’s independent front suspension, a Reyco rear air suspension, and Bilstein shocks. It has a steering cut angle of 55 degrees, a front sway bar, and full air brakes with ABS. Its fuel capacity is 150 gallons.
The Spartan Me2 chassis shifts the engine and transmission “” the heaviest assembly in the chassis “” to the center of the frame, thus distributing the weight more evenly on the front and rear axles. This, in turn, improves the coach’s performance by providing a more stable ride and reduced sway. The powertrain placement also allows the motorhome manufacturer more flexibility when designing the coach portion of the vehicle, with options as varied as a sunken bedroom with a whirlpool tub; a rear garage for a small car, motorcycle, or golf cart; a traveling office, etc.
The Me2 chassis is available in four wheelbase lengths, ranging from 208 inches to 252 inches.
Available power plants for the Me2 are the 330-horsepower Cummins ISC engine (950 pound-feet torque at 1,400 rpm) and the 370-horsepower or 400-horsepower Cummins ISL engine (each generating 1,300 pound-feet torque at 1,300 rpm). The power is put to the road through an Allison 3000 MH electronic six-speed transmission. The Me2’s weight ratings are 34,600 pounds GVWR and 44,600 pounds GCWR. The chassis includes Spartan’s independent front suspension, a Reyco rear air suspension, and Bilstein shocks; a steering cut angle of 55 degrees; a front sway bar; and full air brakes with ABS. Fuel capacity is 100 or 150 gallons.
Spartan Chassis Inc., 1165 Reynolds Road, Charlotte, MI 48813; (517) 543-6400; www.spartanchassis.com.
Western Recreation Vehicles Inc.
The Peak Chassis was created more than six years ago when Western RV entered the diesel-pusher type A motorhome market with its Alpine Coach Limited models. Its sole purpose was to design and manufacture a coach chassis for this particular motorhome. At FMCA’s 2003 summer international convention in Buffalo, New York, Western RV introduced a second type A diesel-pusher, the less expensive Alpine Coach Avalanche Series.
The Peak Chassis used for each motorhome is basically the same. Most of the differences occur in the standards/options list on the finished coaches rather than the chassis. However, there are several variations that should be noted. The chassis used on the Avalanche Series includes a rear-mounted radiator (the Alpine Coach Limited has a side-mount radiator); steel wheels (the Alpine Coach Limited has aluminum wheels); and full air brakes with ABS and traction control (the Alpine Coach Limited has hydraulic disc brakes with ABS and traction control, with air brakes as a deduct-cost option).
The Peak Chassis starts as a raised-rail ladder-type frame with layers of polyurethane enamel primer and overcoat paint for protection against the elements. Powder-coated brackets and grade 8 bolts are used throughout.
The standard engine used is the 350-horsepower Cummins ISC (1,050 pound-feet torque at 1,300 rpm) with the 400-horsepower Cummins ISL (1,200 pound-feet torque at 1,300 rpm) available as an option. Both are mated to an Allison 3000 MH six-speed transmission with an electronic push-button shifter.
The chassis is rated at 33,000 pounds GVWR and 43,000 pounds GCWR. The Avalanche Series has a wheelbase of 252 inches while the Alpine Coach Limited is available with wheelbases ranging from 217 inches to 278 inches.
The Peak Chassis is equipped with an electronic throttle control that is designed to provide an electrical signal to an engine control module in response to the operator’s demand for power. Both chassis models employ a Jacobs compression brake for slowing assistance when equipped with the 400-horsepower Cummins ISL engine. All Peak chassis include a 100-gallon fuel tank.
A heavy-duty Neway air suspension, which is custom-tuned and engineered with individual height control valves at each air bag, automatically compensates for changes in road conditions. Bilstein shocks are utilized at each corner.
Western Recreational Vehicles Inc., 3401 W. Washington Ave., Yakima, WA 98903; (800) 777-4133; www.wrv.com.
Workhorse Custom Chassis
Workhorse Custom Chassis, C8291, known primarily for its gas-powered type A motorhome chassis, joined the type A diesel-pusher market in 2002 with the R Series chassis. The R Series chassis is built with either a straight-rail or raised-rail frame and comes in six wheelbase lengths: 208, 228, 242, 252, 262, and 276 inches.
The standard engine used in the chassis is the 350-horsepower Cummins ISC (1,050 pound-feet torque at 1,400 rpm), with the 330-horsepower ISC (950 pound-feet torque at 1,400 rpm) and the 370-horsepower and 400-horsepower ISL (both 1,200 pound-feet torque at 1,300 rpm) available. All power plants are mated to an Allison 3000 MH six-speed transmission.
Motorhome manufacturers also have options when it comes to the front suspension. An I-beam suspension that incorporates ArvinMeritor trailing arm technology is standard, while an ArvinMeritor Ridestar independent front suspension is optional. All four corners use air springs and Gabriel Ryde FX shock absorbers.
Ride comfort and turning radius are both affected by the different front suspension systems. While the chassis’ riding comfort might be subjective, the turning radii are not. Curb-to-curb turning radii will depend upon the coach’s wheelbase; however, each type of front suspension has a different cut angle. The I-beam suspension has a 50-degree wheel cut angle, while the independent suspension enjoys a 55-degree wheel cut for better maneuverability.
The R Series chassis is available in three weight ratings. Standard is a 28,000-pound GVWR with a 40,000-pound GCWR; the optional packages are a 29,000-pound GVWR with a 41,500-pound GCWR or a 32,000-pound GVWR with a 44,000-pound GCWR. Fuel capacity is 100 gallons (standard) or 150 gallons. The standard chassis has the fuel fill on the driver’s side, but Workhorse also offers manufacturers the option of adding another fill on the passenger’s side.
The transmission resides just forward of the Cummins engine and is coupled to the differential with a very short driveshaft to reduce rear end noise and vibration. The rear differential gear ratio in the Meritor axle is 4.63:1 with QuietRide ring-and-pinion gears to maintain a low sound level while on the highway.
Workhorse Custom Chassis, 600 Central Ave., Suite 200, Highland Park, IL 60035; (877) 294-6773; www.workhorse.com.