Get FinancingExplore The 2027 Cornerstone Luxury Coach Series 6 645D
The 2027 Cornerstone Luxury Coach Series 6 645D is designed for travelers who want every mile to feel as refined as the destination. Combining handcrafted construction with premium amenities and exceptional performance, this luxury Class A diesel motorhome offers an elevated ownership experience from the moment you take the wheel.
Built on Tiffin Motorhomes' exclusive PowerGlide SL chassis and equipped with residential comforts throughout, the Series 6 645D is designed for extended travel without compromising luxury.
Premium Performance Built For The Open Road
The Series 6 645D is powered by a Cummins X15 diesel engine producing 605 horsepower (451 kilowatts) and 1,950 pounds-foot (2,644 newton-meters) of torque, providing the power and confidence needed for mountain grades, highway cruising, and long-distance travel.
The RV’s PowerGlide SL chassis gives the coach a raised-rail design for improved handling and stability. Premium components such as an Allison 4000 MH automatic transmission, a ZF independent front axle, Koni custom-tuned shocks, and Bendix air disc brakes with ABS work together to create a smooth, controlled driving experience.
Additional features like the UltraSteer integrated tag axle and DriveTech ergonomic driving system with the OptiView all-digital gauge display help make every trip more comfortable behind the wheel.
Spacious Living With Residential Comfort
Inside, the 645D floor plan is designed to maximize both space and comfort. Quad slide-outs create an expansive living area, while panoramic gallery windows fill the interior with natural light and your choice of scenic views.
Luxury finishes are found throughout the coach, including genuine leather furniture, heated and cooled driver and passenger seats, and a full tile flush-floor shower. Buyers can personalize the interior with four décor packages and choose between modern or traditional furniture styles to create a space that fits their preferences.
Thoughtful touches throughout the coach create a residential atmosphere that's ideal for extended stays and cross-country adventures.
A Kitchen & Living Space Designed For Longer Stays
The kitchen is equipped with everything from quick breakfasts to full-course meals. A Wolf induction cooktop provides efficient cooking performance, while premium finishes and generous workspace make meal preparation feel more like home.
The AquaHot 600D hydronic heating system supplies continuous hot water while supporting comfortable interior temperatures, making the coach well-suited for travel across changing seasons. Dual inverters also allow air conditioning operation without relying on the generator, providing added flexibility when camping.
Handcrafted Quality Inside & Out
Every Series 6 645D is built with Cornerstone's True-Frame wall construction, creating a stronger, quieter, and better-insulated coach. This durable design helps reduce road noise while improving long-term structural integrity.
Unlike mass-produced motorhomes, the Series 6 is hand-built with an emphasis on craftsmanship and attention to detail. For the 2027 model year, production is limited to just 24 coaches, giving each unit additional care throughout the manufacturing process.
Confidence Throughout Ownership
Beyond its premium construction, the Series 6 645D is backed by a strong ownership experience. Every coach includes a two-year warranty, while a five-year, 100,000-mile warranty covers the PowerGlide chassis.
Owners also benefit from access to more than 450 Freightliner service centers across North America, including RV-focused Oasis locations, along with 24/7 factory-direct customer support for added peace of mind wherever the road leads.
Find Your Next Luxury Motorhome
Ready to experience luxury travel at its finest? Visit RVUniverse.com to explore new and used Class A diesel motorhomes built for exceptional comfort, craftsmanship, and performance.