2016 Entegra Cornerstone 45A

An In-Depth Review of Entegra Coach's Flagship Motorhome
Article Date: January, 2016

Article and Photography by Mark Quasius

Entegra Coach is one of the fastest growing motorhome manufacturers in the Class-A diesel pusher market. With a reputation for quality and customer service that goes well above the norm, this is understandable. Like most RV manufacturers, Entegra has made the usual upgrades in features and amenities with every new model year. But 2016 was a major redesign, featuring redesigned front and rear caps styled to a more modern look. I have to admit that I've admired Entegra's construction and quality since I first took a serious look at them back in 2010. But this time the floorplan as well as the features just all came together for us. We sold our previous motorhome and bought an Entegra Coach. In fact the 2016 Cornerstone reviewed in this article is the one that Leann and I now happily own.

Building a quality product the right way does take time and it takes seven weeks to build an Entegra Cornerstone. Three weeks are dedicated to the basic build of the coach while the next three weeks are spent in the paint shop. The final week is devoted to Final Fit and Finish as well as extensive quality control inspections. The result is a quality built coach that is ready to spend time in the new owner's hands rather than at the dealership correcting manufacturing errors. I was afforded the rare opportunity of being allowed to follow my coach down the assembly line during the build process. I've written an article about that, with extensive photos at This Page for more details, but for now, I'll just concentrate on the finished coach.

Construction Overview

The Entegra Cornerstone is available in a number of floor plans, all of which are 45 feet in length and are built upon Spartan's largest chassis - the K3. The Spartan K3 is a tough chassis, capable of containing all of the stress of a large motorhome with a massive 15 liter engine yet still delivering a smooth ride and excellent road manners. Entegra kicks that up a notch with a number of custom chassis tweaks that make this coach a real joy to drive, such as additional X bracing that further stiffens the frame and provides a solid surface to mount the coach on. The end result is a chassis that doesn't flex and a superstructure that will not twist and loosen up over time.
 

Click Here to view the 2016 Cornerstone chassis spec sheet.
 

The Cornerstone is powered by a Cummins ISX 15 liter engine that produces 600 HP and 1,950 ft-lbs of torque. To some this might seem like overkill but when climbing mountain grades or trying to accelerate up to speed on a busy Interstate's entrance ramp this engine is a welcome relief. You would think that this might be a costly engine to operate when it comes to fuel economy but in fact, it is not that thirsty. The big engine has so much torque that it never has to work hard and the lower gear ratio of the drive axle allows the engine to lope along at a lower RPM. The end result is that it gets the same fuel economy as the smaller 450 HP ISL 9 liter engines under most driving conditions. Large 365/70R22.5 Load Range L tires are fitted to the 20,000 lb. rated front axle while 315/80R22.5 Load Range L tires are fitted to the 20,000 lb. drive and 14,000 lb. tag axles. A 20,000 lb. towing hitch is standard and a 54,000 lb. GVWR and 74,000 lb. GCWR ensure that you'll have plenty of capacity to carry or tow anything you'll ever need. Six wheel disc brakes and the three speed engine compression brake do an amazing job of stopping this coach in short order.

The coach is equipped with Hadley SLS Active Air suspension system. This computer controlled system will adjust the suspension air bags while you drive to level the coach automatically to eliminate crown-of-the-road leaning and other artifacts. This system can also level your coach when parked so that you don't have to deploy the leveling jacks when pulling into a rest area or when parked on soft ground or hot asphalt. It also has the ability to raise or lower the ride height of the coach if you need a bit more clearance when parking or maneuvering at slow speeds. The Cornerstone is also equipped with an Equalizer Systems dual acting hydraulic jack leveling system for those times when you wish to use jacks.

Entegra Coach utilize a thick wooden floor structure that is placed over the steel framework and filled with Flex Foil and fiberglass batt insulation that give it an impressive R33 insulation value. Pex tubing for the hydronic heated floor is also installed. The wooden floor also helps to dampen noise and road noise.

All Entegra Coaches utilize a 2x4 wooden floor structure topped with 3/4" exterior plywood that is located over the top of the typical steel framed substructure. This helps to deaden any road noise, because the wood acts as a buffer to absorb and deaden any road noise or vibrations. It also provides additional room for insulation and gives every Entegra Coach an industry leading R-33 insulation value. An in-floor hydronic heating loop ensures that the ceramic floor tiles remain toasty warm on cool days or nights. The 2-1/2" thick sidewalls are fitted with 1/2" plywood on the interior and reflective flexfoil insulation and vapor barriers are installed before the fiberglass batt insulation, an acoustic grade found in high end studios, is installed. Extensive insulation is also found in the front and rear caps, which is not the normal practice in the motorhome industry. After camping in 97 degree Texas heat and heating the coach in cold Wisconsin weather we've found that the insulation and tight seals made the coach much more comfortable than we were used to. Our air conditioning and heat ran half as much as in our previous coach and the coach was much quieter, both when driving and when parked in a noisy location.

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