Typical Class C GAS mileage

[Joe_T_]

All,

I am sure this question has been asked many times. But, I could not find anything using 'SEARCH' that was pertinent.

We considered a Class A. But, maneuverability and gas mileage considerations has changed my mind.

Our purpose for this vehicle will be affordable travel around the US and Canada. We will travel a month or so, go home and stay a month or so, then travel again. We plan to visit all of the US National Parks possible and many historical sites.

There are four priorities for this future vehicle:

1.) As large of water and waste water tanks as possible
2.) A generator
3.) At least one slide in the living area
4.) LEVELERS!!!

We plan to stay no more than one or two nights in any one spot. Most likely many nights will be spent at Truck stops, WalMart, etc., in addition to the parks. So simple setup and takedown are very important (LEVELERS and any other suggestions are appreciated).

We are considering purchasing a used Class C of 30' - 32', 5 - 10 years old. Most likely it will be a Ford chassis with the V10. It will probably be a Winnebago, but who knows. I want something that has depreciated significantly, but 'lightly used' for its age.

I am interested in what your true Class C gas mileage history has been. Also, any advice/guidance on our plan is appreciated.

Thank you in advance,
Joe T.

[Wiz]

I bought a 4 bolt on BAL scissor jacks for my Class C. Two under the front bumper and two in back just before where the frame was extended. I use a Ryobi drill or impact wrench to run them up or down. They can only raise a corner 3-4 inches so you need to be pretty level to start with.

[Jbrowland]

Not sure if this has been mentioned or not but class C's of the sort the OP is interested in typically don't have auto leveling jacks. IMHO, the OP would be better suited to a class A in the 30 foot range. Same gas mileage as a similar class C and more creature comforts for those one month trips.

[Rovin__Bones]

pnichols wrote:


Way off topic: That story above from the past reminds me of one of mine from the late 1960's involving (among other things) rear differential ratios. An owner once let me drive the real deal - his Cobra roadster. I red-lined her up to 110 MPH in 2nd with 2 gears left and then chicken'd out - enough was enough.

You lucky SOB. I'd donate body parts to be able to get behind the wheel of a Bona Fide Cobra and DRIVE it.

[pnichols]

Rovin' Bones wrote:
A taller gear like 4.10s will give you more top end speed for the same amount of RPM than the 4.56.

My first car was a San Jose plant built 1970 Ford Mustang. 302cu in. displ. C4 trans. rebuilt for street racing and 3.10 differential gear. After I punched it over .030 and added a dyno matched camshaft to the intake and a beefier 4bbl carb, I could hit 150mph at 4600 RPM and still have almost 2000 RPM until redline. It was a dog out of the hole but would really move you down the road in a hurry when you gave her her head. Also, with that low of a gear number in the rear, I could wind it up to 50 MPH in L1, punch L2 and glue you to your seat and not hit D until 95-100 MPH.

Way off topic: That story above from the past reminds me of one of mine from the late 1960's involving (among other things) rear differential ratios. An owner once let me drive the real deal - his Cobra roadster. I red-lined her up to 110 MPH in 2nd with 2 gears left and then chicken'd out - enough was enough.

Kindof back on topic: For our first RV the DW and I bought a new Dodge B250 gas delivery van - with a column shift manual 3-speed tranny and cruising ratio rear differential - that we converted into a camper van. The super tall overall gearing gave that camper rig around 18 MPG from it's 318 cu. in. V8 way back in the low-tech early 1970's (take that Sprinter). However, it was disappointing at times because there would be off-highway dirt roads back in the boonies that I dared not take it on merely because of the grades ... I didn't think I could slowly and carefully go up some of them without burning out the clutch because of the Dodge's overall tall gearing.

The 4:56 rear differential in our Ford V10 Class C probably doesn't detract much from gas mileage versus a 4.10 differential because we cruise 55-60 MPH at around 2200 RPM, and because I use tires of larger diameter than what came on it stock. I prefer the E450 chassis under our small Class C for other reasons ... plus the taller tires provide more ground clearance.

[Rovin__Bones]

A taller gear like 4.10s will give you more top end speed for the same amount of RPM than the 4.56.

My first car was a San Jose plant built 1970 Ford Mustang. 302cu in. displ. C4 trans. rebuilt for street racing and 3.10 differential gear. After I punched it over .030 and added a dyno matched camshaft to the intake and a beefier 4bbl carb, I could hit 150mph at 4600 RPM and still have almost 2000 RPM until redline. It was a dog out of the hole but would really move you down the road in a hurry when you gave her her head. Also, with that low of a gear number in the rear, I could wind it up to 50 MPH in L1, punch L2 and glue you to your seat and not hit D until 95-100 MPH.

[Desert_Captain]

Regardless of the gear ration {4:56 or 4:10}, Tow Haul still needs to be engaged unless you are running well under GVWR. I cannot understand why folks are reluctant to properly use their engine/drive trains. :h As noted the owners manual contains a wealth of information on the proper use of TH.

The engineers at Ford have been successfully designing and building these systems for a very long time. Another benefit of proper TH use is the engine braking on long down hills. Properly engaged you can descend long {as in 10 - 12 mile}, steep {6 - 8 percent}, grades without touching your brakes and you won't burn a drop of fuel.... what's not to love?

:C

[DrewE]

According to the Ford web site vehicle configurator, the E-450 has a 4.56 axle and the E-350 can be ordered with either a 4.10 or a 4.56 axle. Both come in limited-slip and non-limited-slip variants.

A bigger number for the axle ratio means higher engine speed for the same wheel speed (assuming, of course, the transmission is in the same gear). I understand that a bigger number is usually called a "lower" ratio (in the same way that a lower gear in a transmission has a greater reduction than a higher gear). This is indeed somewhat confusing.

[ron_dittmer]

pnichols wrote:

ron.dittmer wrote:
The E350 with the latest 6-speed transmission includes another change. It comes with the same rear axle gear ratio as the E450. So if he has an E350, he might be okay with the tow-haul off because of his naturally lighter load along with that change.

Ron, I couldn't find those rear axle ratios on page 22 of the 2017 E350/E450 Cutaway spec sheet. It does list the E450 as still having a larger differential ring gear diameter than the E350. Does a larger diameter for the E450 Dana differential mean it has a lower ratio than the E350 Dana differential?:

https://www.fleet.ford.com/truckBBAS/topics/2017/2017_E-Series_Cutaway_Stripped_Chassis-Specs.pdf

I get confused when talking "Gear Ratios". I don't know if "higher" means "Easier to pull but running at a higher RPM" or is it the other way around? I do know that since the E350 gets the same now as the E450, it can pull harder doing so at a higher RPM. But with the extra gear in the transmission, it might compare to the previous trans/diff arrangement.

[pnichols]

ron.dittmer wrote:
The E350 with the latest 6-speed transmission includes another change. It comes with the same rear axle gear ratio as the E450. So if he has an E350, he might be okay with the tow-haul off because of his naturally lighter load along with that change.

Ron, I couldn't find those rear axle ratios on page 22 of the 2017 E350/E450 Cutaway spec sheet. It does list the E450 as still having a larger differential ring gear diameter than the E350. Does a larger diameter for the E450 Dana differential mean it has a lower ratio than the E350 Dana differential?:

https://www.fleet.ford.com/truckBBAS/topics/2017/2017_E-Series_Cutaway_Stripped_Chassis-Specs.pdf

[ron_dittmer]

Desert Captain wrote:

The Logans wrote:
We drive by the tach, with the 6 speed tranny, 2,200 RPM gets us about 58 MPH, and 11.2 MPG. We never have to use tow/haul anymore, since we got the V10 / 6 speed combination.

If you are not using Tow haul you are slowly but surely cooking your transmission. Engaging TH even on relatively minor grades will drop your trans fluid temps by 12 - 14 degrees. Not much of an issue now but come summer.... Not only does the use of TH provide for a cooler running trans it also makes it much more efficient.

Tow Haul is there for a number of very good reasons and should be used most of the time the exception being if you are running nearly empty, well under your GVWR. Add a Scan Gauge {or comparable display}, and start monitoring your trans fluid temps and you will quickly see the damage you have been doing by leaving TH off. Your owners manual will have additional TH usage tips was well.

The E350 with the latest 6-speed transmission includes another change. It comes with the same rear axle gear ratio as the E450. So if he has an E350, he might be okay with the tow-haul off because of his naturally lighter load along with that change.

[Desert_Captain]

The Logans wrote:
We drive by the tach, with the 6 speed tranny, 2,200 RPM gets us about 58 MPH, and 11.2 MPG. We never have to use tow/haul anymore, since we got the V10 / 6 speed combination.

If you are not using Tow haul you are slowly but surely cooking your transmission. Engaging TH even on relatively minor grades will drop your trans fluid temps by 12 - 14 degrees. Not much of an issue now but come summer.... Not only does the use of TH provide for a cooler running trans it also makes it much more efficient.

Tow Haul is there for a number of very good reasons and should be used most of the time the exception being if you are running nearly empty, well under your GVWR. Add a Scan Gauge {or comparable display}, and start monitoring your trans fluid temps and you will quickly see the damage you have been doing by leaving TH off. Your owners manual will have additional TH usage tips was well.

:C

[The_Logans]

We drive by the tach, with the 6 speed tranny, 2,200 RPM gets us about 58 MPH, and 11.2 MPG. We never have to use tow/haul anymore, since we got the V10 / 6 speed combination.

[pnichols]

I pretty much compensate for not having a Scanguage by trying to drive as if we had one in our V10 motorhome. We cruise between 55-60 MPH, let the tach get no higher than around 3500 RPM, and drive in the Tow-Haul mode a lot more than we used to.

(I changed my driving habits after a blown transmission with only 61K miles on the RV.)

[Desert_Captain]

"With $20T in national debt, too bad the feds don't have a Scanguage-II type of devise to help them spend smarter."

What he said....


Good call Ron, I cannot imagine any RV'er running without a Scan Gauge {or comparable device}. I run with real time and average MPG along with coolant and trans fluid temps as my primary displays. The information provided by the Scan Gauge makes you a smarter, better informed, more efficient driver and who does not seek that? :S