Pros & Cons of a Diesel Super C

[Snowman9000]

Those of you who have or had a diesel Super C, what are the pros and cons of that class compared to a gas or diesel Class A?

[Explorer1016]

The class 5 braking system is much more substantial as well. The Freight liner M2 is available in several series chassis as well. You have the M2 Light with a low horsepower Cummins and Allison 3000 series trans and 19.5 tire/wheel combo then you can also get a heavier M2 chassis with higher tow capabilities, 19.5 tire/wheel combo and a heavier M2 with the 22.5 tire/wheel combo. Navistar offers similar chassis combinations.

[Explorer1016]

The F550 and the Ram 5500 only share the cab of their so called pickup counter parts. The chassis and drive train components are larger. As an example, my F550 utilizes the Dana 110 series read differential and the Dana 60 front differential. They share the engine but on the class 5 chassis series and above the horsepower is derated but the torque is still there. Steering components are heavier as are springs and perches. Etc.

[AAFD]

To me you have two different classes of Super C, Pickup based units (i.e. Ford F550 and Ram 5500) and large Freightliners.

There is a big difference, like air ride and brakes, 22.5 tires vs 19.5, larger motors (all though not always).

Just my .02 worth.

KC

[anav8or]

We currently have a Jayco Seneca which is built on a Freightliner M2 chassis. Previous to this, we had an E-450-based Thor Chateau.

Things we like:
- A bunch of additional interior space. With the main slide out, we can throw a couple of beanbags on the floor and spread out. The Chateau was rough on rainy days - just not enough room to relax.

- Huge improvement in exterior storage

- Extremely comfortable to drive. In the Chateau, I felt like I was constantly fighting the wind and passing trucks. I was exhausted at the end of a day of driving. The M2 doesn't get blown around at all.

Mileage has averaged around 10.5 mpg and most of our trips involve towing a Honda CR-V. Power up grades isn't tremendous, but we rarely drop below about 55mph. The Ford V10 did a bit better power-wise, but we were getting 7-8 mpg.

The ride in the Seneca is pretty stiff with the tires at max pressure. Once I had our rig weighed, I adjusted the pressure down and the ride improved significantly.

Overall, we're extremely happy with the Seneca. We've done a couple of multi-week trips (2 adults, 3 labs) and it has been great.

[Sites]

I think I would have a harder time trying to find 20k lbs of stuff for it to tow :B

rjstractor wrote:

Dune Hauler wrote:
At this point I am looking into a 600HP Freightliner Cascadia based Super C, that will pull a 20,000lb trailer with no problems.

No kidding, 20K is a light load for that chassis. Those class 8 based Super Cs are really in a class by themselves.

[rjstractor]

Dune Hauler wrote:
At this point I am looking into a 600HP Freightliner Cascadia based Super C, that will pull a 20,000lb trailer with no problems.

No kidding, 20K is a light load for that chassis. Those class 8 based Super Cs are really in a class by themselves.

[Explorer1016]

I have owned 5 gas 3/4 ton and 1/2 ton pickups and 3 diesel 3/4 ton and 1 ton pickups. Now I own an '08 F550 4x4 diesel Super C. Most of the Super C's are geared low because they are focused toward the towing crowd. We tow an enclosed trailer with a full width workbench (empty trailer weighs about 4000#) then I load it up with my 5000# Jeep rock crawler and every tool I can think of plus jacks, jack stands, coolers, extra gear, etc. My trailer weight comes in at about 9000+# loaded. You will have a very difficult time finding any gasser that will tow that type load cross country. We drive from Eastern Missouri to Moab almost annually for the Jeep Safari, we frequent Colorado and go east to where ever we need. Pulling through the Rockies is very hard on a tow rig and the gassers just have a hard time doing this. i'm not sure you can buy a gas powered RV with that high of towing capacity. My mileage is only about 8mpg but I am running a GCWR of about 28,000#'s. My Chassis weighs more that some other Super C units due to the 4 door Lariat Cab and 4x4 drive train and I have 3 slides.

The drive train and under carriage of a Class 5 or above chassis has bigger components than a Typical Class C. Even the gas based Class A chassis's aren't built as heavy as the Class 5.

I run 14 Ply Toyo's on all 4 corners and my rear duals load carrying capacity is higher than the empty curb weight of my RV. My load capacity on just my rears comes in at 15,000#'s.

[Dune_Hauler]

I have had a 5th wheel, class C then to A, now in a Super C. The only complaint is less living space verses length. The towing capacity structural strength and overall build of higher end Super C's can't be beat in my opinion. At this point I am looking into a 600HP Freightliner Cascadia based Super C, that will pull a 20,000lb trailer with no problems.

[RobbieH]

I have never put any type of fuel treatment in any diesel I have ever owned. It is not needed.

Oil change costing 4x as much is not true. And many diesels go much farther on an oil change than a gasser. For example, my 2006 Dodge's oil change interval was 15,000 miles. 12 quarts of oil, and oil filters are not too expensive (I get the Fleetguard Stratopore filters for $14 from Geno's Garage). I had my Super C's first oil change done at the stealership (Ford house) and it cost just at $100. I don't think a V10's oil change costs $25. And I could have done it myself far cheaper than $100.

I got mine, like Sites, for towing capacity. 95% of the time, I have 7,000 lbs behind me. And even in the Rockies, I'm in the passing lane, not the slow lane.

Initial cost for diesel is often offset by resale value, in some cases the difference in resale value can be more than the initial cost of the diesel. When I got my Super C, I sold my Ram for $25,000. I paid $32,000 for it new. Try that with an '06 gas truck.

I have never had to buy new spark plugs for any diesel either. 😄

[pianotuna]

No, I was not referring to DEF. I was referring to a product I used that appeared to work well to make the diesel run more smoothly.

BTW I drive my 28'5" 13,700 lb v-10 @ 49 mph and get an average of 11 MPG US.

I have no difficulties of any kind in the mountains, but of course do not get the same mileage as on the prairies.

Sites wrote:

pianotuna wrote:


Mileage is better but the difference is eaten up by fuel treatment.

I've seen the "diesel is better than gas because of mileage" argument a lot over the years. Not just RVs, but trucks in general. It's kind of a pointless statement if you think about it. Since in 99% of situations, there is absolutely no way the MPG gained will offset the initial premium cost associated with going with the diesel option.

And honestly, the fuel treatment (I assume you're referring to the DEF fluid?) really isn't a big deal. Its cheap and at least my MH seems to consume very little (I've only filled the DEF reseivor twice in 7k miles.) The second time was when I took it to my Ford dealer to change the oil and they just included it in the service for free.

Bottom line, go with a diesel for the additional power over a gasser. Not because of mileage.

[thethrillofspee]

In my old gas motorhome I was in the slow lane with that V10 screaming going over the Sierra's. In the diesel Super C, I'm in the passing lane. You will never make up the fuel cost vs the extra cost of the diesel. Gas was 6 mpg, diesel is 9 mpg going with the flow of traffic or 11-12 mpg going at V10 speed. The driving experience is much better with the diesel especially if you tow.

[Sites]

pianotuna wrote:


Mileage is better but the difference is eaten up by fuel treatment.

I've seen the "diesel is better than gas because of mileage" argument a lot over the years. Not just RVs, but trucks in general. It's kind of a pointless statement if you think about it. Since in 99% of situations, there is absolutely no way the MPG gained will offset the initial premium cost associated with going with the diesel option.

And honestly, the fuel treatment (I assume you're referring to the DEF fluid?) really isn't a big deal. Its cheap and at least my MH seems to consume very little (I've only filled the DEF reseivor twice in 7k miles.) The second time was when I took it to my Ford dealer to change the oil and they just included it in the service for free.

Bottom line, go with a diesel for the additional power over a gasser. Not because of mileage.

[Sites]

ronfisherman wrote:
Sites
Look like you are using a Equalizer type hitch. How does that work with a motorhome?

The exact same way as a truck. You still need to follow the max tongue ratings for the MH hitch.

[pianotuna]

Hi,

Diesel Oil change is approximately 4 times as costly.
Mileage is better but the difference is eaten up by fuel treatment.
RV is quite a bit heavier with diesel engine
Initial cost is 15 grand more
changing to winter fuel is necessary in the north