Best MPG from most popular MH engines

midnightsadie wrote:
if your looking mpg look at diesels the ones with v6 or the 5cyc mercedes benz diesel.

x2

Kit Carson wrote:
Just wondering if using cruise control is detrimental to achieving a reasonable MPG. I use my cruise control on flat ground but not up and down hills. Maybe I should not use it at all. My unit is a 29' Winnebago Class C and I average about 8 MPG w/o toad.

A while back I pretty much stopped using cruise control because I think I get better MPG when it's not on, particularly in hilly areas. In southern Fl. an overpass can be considered a hilly area. :B Just from watching my scan gauge I feel that not using cc is beneficial.
Obviously I could be totally wrong, but again it's just a feeling, nothing scientific, or any proof for the idea.

Nothing like a 6cyl diesel for inherent stability and inherent efficiency.

My 7700# Dodge 4X4 PU with 6cyl Cummins (2006) gets 18-20mpg unloaded and is one VERY fast truck. With a 2600 pound camper and gear (Pop-Up camper)I get 12-16. I cruise at 1800RPM at 65mph. Truck has just under 200K and only service has been a waterpump, oil, filters. I do have a "Juice with Attitude" tuner installed for over 400HP and over 750fpt

I frequently pull a 10,000#, 30' bumper tow trailer and performance and mileage doesn't change. The truck has never down shifted pulling hills in PA / WV and out west in Montana / Wyoming. It just pulls and maintains 65mph no mater the road conditions.

This is an amazing engine, I'm not sure why it isn't used in more MHs.

Rbertalotto wrote:


This is an amazing engine, I'm not sure why it isn't used in more MHs.

It is used in a lot of MH's. Just not in the smaller Class C's. Last weekend we attended a local RV show. Saw several low priced Class A diesel pushers with the 6.7 Cummins in them. They also had 2 of the Jayco 37' Super C's there with same engine.

Mine is the 5.9 24valve, which gets substantially better mileage than the 6.7. The best version of all was the older 12 valve version that could burn any fuel and I have friends that I've verified over 21mpg on a trip with about 1500 pounds in the bed!

Figure on 7-9 mpg under most driving conditions unless you are driving a short rig with little weight aboard, max tire pressure, in really flat country, no wind, and speeds no higher than 55mph without cruise control. Buying a rig with diesel power can get better mpg but extra cost of rig with diesel engine and it's maintenance, plus higher cost per gallon of diesel fuel, may not be cost-effective unless you drive 20K miles or more per year. On the west coast we have little flat land and our mileage with Ford E-450 and 27 foot rig is often around 7-8mpg.

MPG is only one major cost factor in motorhoming, there is depreciation, repair or replacement of appliances and devices, state taxes and registration fees, smog testing, insurance, emergency road service, and tire replacememt, plus routine engine, cooling system, and brake service/repairs and miscellaneous house box maintenance and repairs. Similar to owning and maintaining a cabin cruiser or an airplane. Buying an old rig can save money if you can do most repair and maintenance work yourself and have workspace,tools and time.

so this guy asks about 460's and 440's (old V8's) and folks suggest Mercedes Diesels? Come on now.

From your original list, all I'd do is change the GM version from a 350 to a 454. All the big old V8's are going to be similar, much more dependent on your right foot than anything else.

Why care about mpg, worry about how much time you have left to travel.

Given all else equal, I suggest this priority.....

1) Chevy (best fuel economy of the three)
2) Ford
3) Chrylser (worst fuel economy of the three)

I would not consider a......
Chevy older than a 1996 (get the later body design)
Ford older than a 1997 (get the Triton V8 or V10 engine)
Dodge unless it's a Sprinter

But the newer the better. For example the Ford got better mechanically around 2000, again in 2004, again in 2006, and again in 2008. I believe 2009 thru 2013 are identical. Fuel economy might have improved slightly in 2006 with the introduction of the current-day Torqueshift transmission with tow/haul mode.

I would never consider any carbureted engine for it's poor fuel economy and lesser performance.
I advised the Ford Triton because the 460 engine is prone to exhaust manifold cracking.