Could some of you give me an estimate on the gas mileage I would expect on a E450 Class C 32 foot long?I realize driving conditions, weight, personal driving habits all are factors however, I would like to get other's opinions. The current owner says he gets 9-10 mpg - no toad.

I consistent get 7.7 mpg on a E450 Fleetwood Jamboree 31M pulling a 2015 Ford Focus.

9-10 miles per Imperial Gallon would be ball park, from my experience oven 40,000 miles with a 28 foot 2004 E450 pulling a toad.

Hi,I drive 49 mph (78 kph). That gets me to 10 mpg US (12.5 Imperial) if there is no head wind. If I drive 50 mph (80 kph) that drops to 9 mpg US.I do have oversize tires and air tabs.

09 Cambria 31'. over the last 14,759 miles I averaged 8.23 MPG. Sometimes I pull a 20ft. trailer weighing just under 5ooo lbs. sometimes four down on my jeep. I have recorded as high as 11.12 and as low as 5.08 which was in the wind pulling the enclosed trailer. I made a trip to Las Vegas, one way around 275 miles and recorded the mileage, always do, next trip I pulled the jeep and the mileage difference was minimal. 62MPH is the sweet spot on my rig.

Depends a lot on the transmission. Our newest motorhome has the new 6 speed transmission. Driving at around 60mph, we averaged 11.2 MPG from West Virginia to Florida and back. The new tranny is much quieter, and we were able to use the cruise control for most of the trip.

Gas mileage E450 | Good Sam Community

pianotuna
Nomad III
May 11, 2016
I went to 235/85r16 from 225/75R16 which did require new rims to have the correct offset for the dual rear tires.

I did so for two reasons. One was carrying capacity, and the other was for a taller tire. I'm more than pleased with the results.
sullivanclan
Explorer
May 11, 2016
Great information. We are somewhat familiar with increasing tire size for our jeeps, but hadn't thought about the motorhome. That is helpful.

matt
pnichols
Explorer II
May 10, 2016
sullivanclan wrote:
Mr Nichols, when you say bigger tires, what was stock, and what tire size did you go to? Was there any concerns with space for the rear wheel wells?

Some great info people......

Thanks

Many U.S.-built Class C motorhomes come stock with 225/75R16 Load Range E tires. At the first tire change on our 10 year old E450-based Class C, I changed to 215/85R16 Load Range E tires. The weight-carrying specification is identcal between these two tire sizes of the same Load Range.

These 215 tires actually have a larger diameter than 225 tires do (but the 215 tires are slightly narrower, too). These 215 tires have about a 1.2 inch larger diameter ... which translates into lifting the entire motorhome one-half of that ... 0.6 inches. Lifting a vehicle using larger diameter tires results in not just a "frame and body lift" like as is the case with most "lifted" pickup trucks. Larger diameter tires lift everything on the vehicle up ... the axles, the differential(s), the springs and their attachment points, the shocks and their attachment points, the transmission, the oil pan, the front steering components, etc..

However, larger-then-stock diameter tires do cause the speedometer to read too-slow. Our speedometer now reads about 1/2 MPH too slow, which is trivial and of no concern to us ... but you do have to keep this in mind when trying to use odometer readings to keep track of gas mileage. What the larger diameter tires do is serve to make the overall drive ratio for the vehicle "taller" ... in other words somewhat counter the E450's lower rear differential ratio by making the E450's overall drive ratio closer to that of the E350 due to the E350's taller rear differential ratio. All other things being equal, this can increase E450 motorhome mileage upwards towards that of an E350 chassis ... while at the same time getting the other advantages of an overkill E450 chassis under a small Class C rig.

The slightly narrower 215 tires also provide a little more air space between the rear dual tires, which permits a bit more air flow between the duals' inner sidewalls for improved cooling when traveling in warm weather.

We like the little higher ground clearance when taking our Class C off-highway (we're rockhounds) - and for less chance of scraping when entering and exiting parking lots.

Some folks in these forums have replaced their Class C's tires with even larger diameter tires than what the 215 size provides. The Ford E350 and E450 wheel wells have plenty of room for larger diameter tires than that of 225/75R16 size.
tpi
Explorer
May 10, 2016
Desert Captain wrote:
"Probably in some cases the E450 could pull a hill in a taller gear than the E350."

Why? The E450 does not have more power than an E350, they both have the same motor and transmission. The E350 has 4:10 rear end and does not need the 4:56 that comes with the E450 {to handle the extra load}.

That's why the 350 will always be turning more slowly {as in burning less fuel}, than the 450. Also that same engine in the 350 will be pulling a couple of thousand pounds less {assuming both are loaded to their respective GVWR's}.

If you are going to be towing or loading heavy, as in near your GVWR, the extra payload (assuming there is any), of some 450's and lower rear end make a lot of sense but they come with a stiffer ride and less mileage. Many of the larger Class C's are so heavy to begin with due to slide(s), levelers etc. they may not have much remaining payload available right out of the showroom.

One thing to look for when shopping for an E350 is the 55 gallon {optional}, fuel tank that comes standard on the E450. IMHO: The standard 40 gallon tank on many 350's lacks sufficient range.

:C

I think you're quibbling here because that is pretty much my point. But as life is, it isn't always that simple. There very well could be a time when an equal weight E350 and E450 could be one gear apart on a hill, with the E450 turning slower. That hill could be pulled in 4th for example in E450 but not on the E350 due to the axle ratio. But as I said, after a complete trip, the total engine revolutions of the E350 is very likely to be lower. Certainly if the E350 was lighter or more sleek, that would contribute to lower total revs.
sullivanclan
Explorer
May 10, 2016
Mr Nichols, when you say bigger tires, what was stock, and what tire size did you go to? Was there any concerns with space for the rear wheel wells?

Some great info people......

Thanks
pnichols
Explorer II
May 09, 2016
We have only a 24 foot Class C (~11,800 lbs. loaded for travel) on the over-kill E450 chassis.

However we have reduced the V10's revolutions per mile by putting tires on it of a larger diameter than is usually used on Class C motorhomes (in the U.S.). These tires and the E450 chassis gives us: Better ground clearance all around, a stiffer chassis frame (slightly higher strength/thicker steel) for less coach structural stress on rough roads, longer brake life and reliability than an equivalent weight E350 Class C due to the E450's larger brake disk swept areas, a larger diameter main driveshaft for perhaps less vibration at certain speeds, and a wider (than the E350) rear stance for improved stability in cross winds and on road curves.

Chassis over-kill is usually a better way to go - if it's available - for a given size Class C and if one can afford the higher cost for it up front, and if one can put up with it's harsher ride. By the way, we have helped our harsher rear ride by installing Koni Frequency Selective Damping (FSD) shocks in the rear where the stiff leaf springs are located.

This whole "Ford E350 versus E450 or Chevy 3500 versus 4500" chassis option thing relative to small Class C motohomes really has me wondering what we would do in the future if planning to buy a later model small Class C. With all this OEM migration to use of the "more modern" lighter duty chassis ... when the E450 and 4500 options are no longer available ... it looks like future small Class C buyers may have to live with a no-other-choice chassis under their smalll Class C that is loaded very close to it's advertised maximum.

We can load our Class C with the freedom of no consideration for over-loading while at the same time it's "over-kill" chassis provides handling and stability that have been excellent under all conditions during it's over-60K mile life.

Note and FWIW: There a few Class C manufacturers that still at this time offer their small 23 - 25 foot long Class C motorhomes ONLY on the E450 chassis ... even though based on the finished weights of their products the E350 chassis is rated for it.
Desert_Captain
Explorer III
May 09, 2016
"Probably in some cases the E450 could pull a hill in a taller gear than the E350."

Why? The E450 does not have more power than an E350, they both have the same motor and transmission. The E350 has 4:10 rear end and does not need the 4:56 that comes with the E450 {to handle the extra load}.

That's why the 350 will always be turning more slowly {as in burning less fuel}, than the 450. Also that same engine in the 350 will be pulling a couple of thousand pounds less {assuming both are loaded to their respective GVWR's}.

If you are going to be towing or loading heavy, as in near your GVWR, the extra payload (assuming there is any), of some 450's and lower rear end make a lot of sense but they come with a stiffer ride and less mileage. Many of the larger Class C's are so heavy to begin with due to slide(s), levelers etc. they may not have much remaining payload available right out of the showroom.

One thing to look for when shopping for an E350 is the 55 gallon {optional}, fuel tank that comes standard on the E450. IMHO: The standard 40 gallon tank on many 350's lacks sufficient range.

:C
tpi
Explorer
May 09, 2016
Jbrowland wrote:
Interested to know if the E350 performs the same MPG wise as the 450? I have the E350 and consistently average exactly 10mpg at the end of a trip from say LA to Yosemie Valley and back doing an average of 59mph or so. I also have a 24 foot class C RV so I am likely lighter than the 30 ish footers discussed, although I would assume the E350 has to work a little harder on the hills than the 45o does?

Most of it is in the axle ratio and that is most beneficial when you're rolling steady in top gear. Keeping the RPM down on extended cruising will help the MPG. On mountainous terrain it just depends on what gear it happens to fall in on each hill. Probably in some cases the E450 could pull a hill in a taller gear than the E350. But overall the E350 probably accumulates less engine revolutions for a trip and saves fuel as long as you're in the weight rating.

These V10s don't have variable valve timing which can save a bit of fuel. The good thing is they aren't fussy about fuel octane and seem to burn low priced regular fuel without issues.

If you can stand going 55 MPH, that is probably the best way to save fuel on these RVs
Bordercollie
Explorer
May 09, 2016
Most RV's have flat fronts and rears, much aerodynamic drag which builds up drastically as speed increases past 50mph . Bucking headwinds and sidewinds, rolling resistance of tires due to weight of rig, climbing grades. RV's and box trucks are much heavier and not streamlined like cars, most of which don't get terrific mpg either when driven faster than 55 mph.
jrobert01
Explorer
May 09, 2016
JNorton wrote:
jrobert01 wrote:
Well i worked for my money and i like to take care of it any way i can and the more gas mileage the better.That said i must be the worst driver or the worst something.I have had several motor homes over the past 30 years except for the Toyota i never get more than 7 and i drive 55 or 62 on interstate brake slowly accelerate slowly and try to get the best mileage i can but that is my best.I have a 2008 32ft.four winds and i live in Tn.Do a lot of long trips. Tell me why i get so much less mileage than everyone else.Lets go with the sarcasm.

2008 Fleetwood 32' 8 mpg at 62 mpg. I just accept it as part of RVing.
Lot of hills in TN.

If the roads are hilly it drops to 7.

Forum Discussion

Gas mileage E450

About Motorhome Group

Related Content

rv gas mileage

Gas Mileage

gas mileage

Gas Mileage

2016 F250 6.2L gas mileage