Ford 7.3 Liter Triton engine?

[Chateau_Nomad]

Originally Posted by Jimbo56

I’ve always wondered why Ford doesn’t use the 6.7L turbo diesel in an F53 chassis. My old set up with a 2015 F350 dually diesel pulling a 12000 lb 5th wheel used to get 15 to 17 MPG. And went up Black Mountain on I40 in NC like the trailer wasn’t even there.

I'd venture that it is more about economy of production. It's possible that chassis modification from gasser to diesel would increase retail price enough to push the units into the larger "standard" diesel territory, negating any perceived marketing gain.

The drag coefficient of your 350 dually is also MUCH lower than the typical square box of a class A. Even the front of the 5th wheel is rounded which greatly reduces drag.

But it is interesting how the diesels jump from the small Mercedes all the way to generally behemoth pushers... with no real middle ground. Missing too is a class C diesel...

[Chance]

I agree it’s likely due to economy — and or lack of demand for that combination due in part to higher cost.

Motorhomes are generally driven very little compared to trucks, so opportunity to recover higher initial cost is not there at same level. Diesel in F-550 is offered because development cost is spread over 1,000s of commercial trucks, whereas RV chassis are limited volume by comparison. In an F-53 application the cost could be much higher than $10,000 per unit.

FRED (front engine diesel) motorhomes have been manufactured but not very successful in sales. Noise and vibration of sitting pretty much directly over a Diesel engine with crappy insulation in between probably did not help.

[RACarvalho]

Originally Posted by Chance

....FRED (front engine diesel) motorhomes have been manufactured but not very successful in sales. Noise and vibration of sitting pretty much directly over a Diesel engine with crappy insulation in between probably did not help.

I would say this is probably one of the main factors.
I added sound deadening material to under the cabin region on my MH, including wheel wells, to reduce road noise and heat for the 7.3L V8 is a somewhat silent engine but the insulation is really poor in these RVs...
Can't imagine the noise level if a diesel was there....

But if someone wants to try, I believe a Cummins dealer can retrofit a F53 based MH with their 6L engine....

[EA37TS]

Originally Posted by Chance

I agree it’s likely due to economy — and or lack of demand for that combination due in part to higher cost.

Motorhomes are generally driven very little compared to trucks, so opportunity to recover higher initial cost is not there at same level. Diesel in F-550 is offered because development cost is spread over 1,000s of commercial trucks, whereas RV chassis are limited volume by comparison. In an F-53 application the cost could be much higher than $10,000 per unit.

FRED (front engine diesel) motorhomes have been manufactured but not very successful in sales. Noise and vibration of sitting pretty much directly over a Diesel engine with crappy insulation in between probably did not help.

All Super Cs are FRED and sales have been extremely successful.

[Chance]

Originally Posted by EA37TS

All Super Cs are FRED and sales have been extremely successful.

As far as I know Dave, most people would not refer to a Super C as a FRED, even though they have the Diesel engine in front.

I have always seen the term FRED used for Class A diesels to differentiate between a Diesel Pusher and a Front Engine Diesel.

In my opinion having the Diesel engine up front and separated by an OEM firewall as in your Super C makes a huge difference versus sitting above the Diesel engine with RV manufacturer’s floor and doghouse to control noise.

I looked at buying a FRED with Cummins 6.7 and noise was so bad that it was a deal breaker from start. The rest of unit was appealing at the time, though our needs are smaller now.

Thinking about it, the compact Mercedes Sprinter Class A FREDs from Winnebago with 3L V6 were not too bad as noise goes. Technically they were FREDs though I don’t recall anyone referring to them as such.

[Chance]

Originally Posted by RACarvalho

I would say this is probably one of the main factors.
I added sound deadening material to under the cabin region on my MH, including wheel wells, to reduce road noise and heat for the 7.3L V8 is a somewhat silent engine but the insulation is really poor in these RVs...
Can't imagine the noise level if a diesel was there....

But if someone wants to try, I believe a Cummins dealer can retrofit a F53 based MH with their 6L engine....

I think it would be easier and cheaper to trade for a FRED if buyer can find a motorhome they like; when having a diesel is that important. Engine swaps are too difficult and thus costly today for me to consider. And I have, just not to a diesel.

Over the years I’ve seen some smaller units with Isuzu engines, some with Cummins 6.7 (including Thor products) and also 4.5L V6 and 6.0L V8 engines made by International, and also branded by Ford for some of their trucks. Thor (brands) have manufactured a few in the past. I’m not aware of any presently.

[Muggs]

Speed/drag is a big impact.

1996 GMC Yukon with 350 Vortec...
17 to 19 MPG commuting to work/vacations.
12 MPG towing 5300 to 5500 lb open race trailer.
7 to 8 MPG pulling 20' open fishing boat 3600 lb. Wide hull.

Latter 2007 Chevy Suburban 5.3

21 MPG with 4 people before e10
12 to 14 MPG pulling 5300 to 5500 lb race open race trailer.

Drag with boat killed MPG on both. Yukon still owned by buddy and just passed 250k miles. SUV still in service.

Vegas still 9 to 11 MPG with ot without trailer.

[RVthereyet]

I realize I‘m late getting in this but the answer to Chat Nomads original post is in his 2nd post with the addition of the 1st posts by bothEA37TS and 16ACE27.