Super C Buyer’s Guide: Freightliner S2RV (Diesel) and Ram 5500 (Gas) Models Compared

## Super C Motorhomes Beyond the Ford F-550 Most Super C motorhomes ride on the Ford F-550 or F-600, which we covered in our [F-550/F-600 buyer’s guide](/blog/super-c-motorhome-buyers-guide-ford-f550-f600). Two other chassis matter if you’re shopping this segment: - **Freightliner S2RV**, a medium-duty truck chassis under the largest Super C coaches, with a Cummins diesel. - **Ram 5500**, a heavy-duty gas chassis cab, used by Dynamax for its Isata 5 Super C. The Freightliner is a diesel with a DEF system; the Ram 5500 coaches we fit are gas with a single fuel fill and no DEF. Both have a fuel fill with no locking door from the factory. ## Watch Out for Similar Names Several brands sell a big Super C on the Freightliner and a smaller one on the Ford F-550 under nearly the same name. Check the chassis before you compare prices or order parts: - **Jayco Seneca** is on the Freightliner S2RV, while the **Seneca XT** is on the Ford F-550/F-600. - **Entegra Accolade** and **Accolade XL** are on the Freightliner S2RV, while the **Accolade XT** is on the Ford F-550/F-600. - **Dynamax Isata 5** is on the Ram 5500 (gas), the **Isata 6** is on the Ford F-600 (diesel), and the **Europa S** is on the Freightliner S2RV. ## Freightliner S2RV Builders and Models - **Jayco**: Seneca (37K, 37L, 37M, 37TS, 37RB, 37FS) and Seneca Prestige - **Entegra Coach**: Accolade and Accolade XL - **Thor Motor Coach**: Inception and Pasadena - **Tiffin**: Allegro Bay (34DB, 38AB, 38BB, 38EB) - **Newmar**: Grand Star (3444, 3940, 3948) - **Dynamax**: Europa S - **Renegade**: Valencia (35MB, 38BB, 38RB) - **Nexus RV**: Wraith (30F through 37F) These are the biggest Super C coaches, often around 35 to 40 feet, with heavy towing capacity and an air-brake medium-duty chassis. They need more parking space and a chassis service center that works on medium-duty trucks. ## Ram 5500 Builders and Models **Dynamax** builds its **Isata 5** (28SS, 30FW, 34DS) on the gas Ram 5500. It is the only Ram 5500 coach we fit. (The Isata 6 is on the Ford F-600 diesel — see the [F-550/F-600 guide](/blog/super-c-motorhome-buyers-guide-ford-f550-f600).) The Isata 5 is shorter than most Freightliner coaches, easier to drive and park, and any Ram dealer can service the chassis. ## What to Compare When You Shop - **Length and parking.** A 38-foot Freightliner coach and a 30-foot Isata drive very differently. - **Brakes and service.** Medium-duty chassis may use air brakes and need truck service centers. The Ram uses hydraulic brakes and is serviced at Ram dealers. - **Towing.** Both chassis tow well. Check the coach’s hitch rating, not just the chassis. - **Fuel and DEF.** The Freightliner is diesel with a DEF tank, a second fill point to protect. The Ram 5500 Isata 5 is gas, with one fuel fill and no DEF. See our post on [DEF theft and contamination](/blog/def-tank-lock-rv-diesel-exhaust-fluid-security). ## How to Lock Down the Fuel Fill Neither chassis comes with a locking fuel door. Fuel is expensive and Super Cs often sit at campgrounds and storage lots, which makes them a target for siphoning and tank contamination. Here’s what our fitment database lists for **The RV Fuel Vault™**: - **Dynamax Isata 5 (Ram 5500 gas):** 1 small door, RVFV-1001S Small Standard Single, $159.95, plus the RVFV-SS100 single-door security screw pack - **Freightliner S2RV coaches:** RVFV-1002L Large Standard Single, $169.95 pre-order. Fit is confirmed on the Nexus Wraith. For the other S2RV coaches listed above, the fit is inferred from the chassis and still being confirmed, so send us a photo of your fuel fill before you order. [Check your coach in Find My Fit →](/#compatibility) | [Pre-order →](/#pre-order) ## Other Chassis Guides - [Super C: Ford F-550/F-600](/blog/super-c-motorhome-buyers-guide-ford-f550-f600) - [Class C: Ford E-350 and E-450](/blog/class-c-motorhome-buyers-guide-ford-e350-e450) - [Class A gas: Ford F53 and Workhorse](/blog/class-a-gas-motorhome-buyers-guide-ford-f53-workhorse) - [Class C and Super C: Chevrolet and GMC](/blog/class-c-super-c-buyers-guide-chevrolet-gmc-chassis) Questions? Call 941-732-0452.