Never settle.

You’ve worked hard and earned the ability to explore new places and meet new people on your time. We’re here to make sure your journey is safe, smooth, and always first class. Entegra Coach and Spartan RV Chassis partner to be co-pilots on the adventure of a lifetime.

Entegra’s Cornerstone is built on the 45’ Spartan RV Chassis K3 605 chassis. Designed, engineered, and made in America with the finest components creating a premier foundation for the most discerning RV makers and owners.

Spartan RV Chassis makes the only chassis built exclusively for motorhomes. We didn’t take the easy route and modify a heavy truck chassis for our partners at Entegra. We knew they wanted an unmatched ride and uncompromising durability that was as smooth and quiet as it was safe and well-appointed. So, we built them the unique K3 605 chassis from the ground up. The highest-quality materials provide reliability and dependability, and constant innovation means you’re safe & secure. Spartan RV Chassis provides a comfortable customer experience, nationwide service, and the best warranty in the business.

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Premium Features

  • E-Z Steer for a smoother driver experience and reduced driver fatigue
  • Power tilt & telescoping steering column
  • Independent front suspension
  • Electronic suspension control system with self-leveling feature including air compressor for extended stays
  • Automatic heated moisture ejectors with color-coded lanyards
  • Side-mounted service center
  • Connected Coach digital dash with 15" display
  • Passive steer tag axle
  • 3-stage engine compression brake
  • 20,000 lb towing capacity
  • New SMART Steering wheel with Graphic Instrument Cluster navigation, screen view selection, wiper, phone, and media control
  • Push button start
  • Suspended adjustable pedals
  • Air disc brakes at all wheel positions
  • Auto headlamps
  • Rain sensing wipers
  • K3 605 Chassis



Peak HP

605 hp @ 1,800 rpm



Towing Capacity

20,000 lb


3-year/50,000 mile

Safety Innovations

Spartan RV Chassis Advanced Protection System – Cornerstone

  • Automatic Traction Control (ATC)
  • Adaptive Cruise Control (ACC)
  • Electronic Stability Control (ESC)
  • Collision Mitigation System with Adaptive Cruise Control
  • Tire Pressure Monitoring System (TPMS)
  • Safe Haul (The industry’s original factory-chassis integrated air supply for tow vehicle supplemental brake systems)



Parts Manuals

Operators Guides

Service Guides

Service Manuals

Wiring Manuals

Alternative Fuels


Ford Transit

RAM ProMaster