Stupid Question on Generators

[91tiger]

Just starting to explore moving up from a class B to class C. Do most of the class C generators run off propane or gasoline? Seems like running off of gasoline from the unit's fuel tank would be the way to go. If a unit comes with a propane generator, would it be easy to switch out for a gasoline model of the same size?

The Coachmen Freelander specs say it is a "gas" generator. I assume that is gasoline not LP Gas?

[pnichols]

The OP's RV is probably on the Ford E350 chassis.

91tiger .... if so, will/does it have an approximately 36 gallon fuel tank or a 55 gallon fuel tank?

If it's the 55 gallon tank then IMHO it's a no brainer - go with the gas (Onan?) generator.

With that setup you either get about a 500 mile travel range with no generator run time ... or a whole bunch of generator run time plus a goodly amount of travel range on top of that.

We love that setup in our 24 foot E450 Class C and as a bonus the Onan is even fairly quiet and vibration-free for pleasant long runs of the air conditioner when drycamping. I estimate that our built-in Onan generator consumes around 0.4 gallons of gasline per hour when running the 13.5K BTU air conditioner (... if the compressor portion of the air conditioner is cycling some, not running continuously).

[91tiger]

Great information, thanks. While I absolutely love some of the diesel Super C's like the Jayco Seneca, they just aren't in my budget right now. I'm looking hardest at a Coachmen Freelander 22QB, which would be a gas coach and according to the information in this thread it should be a gasoline genrator too. That suits my needs perfectly because the Everglades Park, where I will primarily be using it, has gas at the Marina where I launch every day so running out of generator or coach fuel won't be an issue.

There are a lot of days we will have to run back in to the marina to dodge a thunderstorm and have to wait it out in the RV before we can head back out to fish. In my class B with no generator, we cook hanging out in the van unless we crank the engine. Having a generator to run the A/C and be able to catch a nap and relax will be stellar.

[Old_Crows]

Oh My! That didn't come out right...I think...

Newish Sprinters have 100L / 26ish Gallon tanks. 5.3 gallons are the "reserve" which gives about 20 gallons of "usable" fuel before the last bar on the fuel gauge disappears and starts flashing. 3/4 of 20 = 15. Leaves about 5 -8 gallons available to the Sprinter only. As I understand it, the generator pick up is set to 3/4 of tank. You might have as much as 18+ G or as little as 15ish usable to,the genny. At the campsite, it is what it is.... MINUS whatever you used getting there. Regardless, you may not have the mythical hours of generator run time with a diesel as the run time is limited by the actual fuel above the pick up. It is what it is....

I get nervous when that reserve warning fires up. I'm in Texas...it can be a very long ... very long... white knuckle drive watching that blinking light trying to get to a fuel point. So, I plan my fuel stop about every 300-340 miles, or roughly 20 gallons burned. That gives about 75-80 miles available on reserve... Just in case. Not keen on pushing this beast down the highway......

[Old_Crows]

Excellent question... I don't know. But on a Sprinter the fuel tank is under & behind driver's seat. Generators on Views and others are usually just behind the starboard duals. So you got to draw diesel through 15 - 20 of fuel line and up and over the drive line and rear axle. A SWAG says its a pain in the gas to suck fuel back to the genny on the opposite side of the RV. Unlike the Sprinter fuel system, I'm not aware of a return line to the fuel tank so its not likely self purging.

[Dusty_R]

Old-Crows.
Very good write up, except, if you use 15 gallons, getting to your camp site, with the 3/4 tank generator dip tube in a 20 gallon tank, there will be nothing left for the generator.

Question. If a diesel generator runs out of fuel, do you have to bleed the fuel injector pump? If so, is it a difficult job ? Is this one more strike against a diesel generator ?

Dusty

[Old-Crows]

Tiger, This may help...... a comparo I did for someone a while ago on LP vs Diesel Onans in Winnebagos. Cost advantage, weight advantage, power advantage at altitude and higher temperatures & separate fuel system, all go to the LP 3200. Although some of the advantages are narrow, weight for example, it may be only important if your weight capacity is small. Fuel consumption difference in lbs/hour is insignificant but the edge goes to the diesel if you are running at near rated output by a schoche if at moderate temperatures and altitude. Not significant since one hardly runs max output. The edge goes back to the LP's slightly lower consumption at mid-power output. Maintenance appears to favor the LP version due to diesels having the problems of all diesels... carbon, gumming up, fuel problems, etc.. LP burns cleaner and should 'theoretically' have less unscheduled maintenance/repairs. Significant disadvantage for LP is that it may have vaporization problems down around 20F. Do you camp in below freezing weather? No discussion about gelling diesel at those temps... which could be a problem. Last, you are going to carry LP anyway as the WH, fridge, heater all run off LP.

Noise levels are the same. Except.... diesels import more low frequency sound wave and vibration into the large panels in the coach. They have an annoying (to us) low throbbing noise inside and out side. The LP does not. Diesel is also stinky running.... your neighbors might appreciate that an LP does not smell as badly.

As before, if it's a diesel and on a Sprinter chassis, you can only access the upper 3/4s of the fuel tank. The wisdom of a seemingly endless diesel fuel supply is illusion. For a Sprinter, assuming a full 20 gallon tank, roughly 15 gallons is available to the generator ... MINUS what ever you have used getting to the campsite. So if you used 15 gallons getting there you have only have 5 for the generator before it shuts down... and that remaining 5 gallons is needed to get to more fuel .. not counting the 5 gallon Sprinter reserve. A working Class C Sprinter will get about 14-16 MPG. OTH, with an LP system you can arrive at the campsite with a near full LP tank with careful LP management it can last a long time.... and you don't eat into your diesel fuel. (MPG on a working 3.0L turbo diesel Sprinter Class C is about 14-15 MPG on the flats ... less in hills. So once you suck down to 1/4 tank you only have 5 + 5 gallon reserve. That's about 140-150 miles. Class C out of fuel is a really big boat anchor.....)

Quick assessment:
https://drive.google.com/file/d/0BzXeY3pXinO9SldITzlGNHFUNGs/view?usp=sharing

[mlts22]

To further muddy the water, some class "C"s like the Winnebago View have by default a LP gas generator. As an option, they have a diesel generator.

If the "C" is a diesel, it most likely runs on propane, perhaps runs on diesel. If it is a gasser, it usually will have a gasoline generator. However, it can't hurt to look at a picture of the generator or ask the seller about it.

[Bobbo]

Most built-ins burn the same fuel the engine burns. Gas units have gas generators, diesel units have diesel generators. Usually.

Most units are designed so the generator dies from fuel starvation when the vehicle fuel tank is 1/4 full. That is so you can't start the generator and run the RV out of fuel without knowing it.

[hotbyte]

If you do go with a class C, be aware that the fuel pickup for the generator is at the 1/4 tank level. So, once you are down to 1/4 tank of gas the generator runs out of fuel. At least all I've seen are this way...

[91tiger]

Exactly the information I needed, thanks. I would be powering mainly the A/C and fridge with the generator. Most of the campiing I do is while fishing in South Florida. The A/C is a must. It would be easy for me to refill the vehicle's gas tank inside the Everglades Park at the marina but I would not be able to refil propane so knowing most are gasoline powered really is good to know.

[navegator]

Most class "C"'s are built on a cutaway Ford or the Chevrolet chassis, very few are Diesel, the majority are gasoline and the generators are also powered with gasoline, having a separate propane tank is a waste of space and weight, specially today with slide outs that eat into the carrying capacity of the units.

Diesel "C"'s tend to be very loud in the cabin since part of the engine and all of the transmission are in a very thin dog house next to the occupants, I would not like the noise and racket next to me for several hours.

The generator taps into the chassis fuel tank and is designed to stop delivering fuel to the generator when the fuel tank reaches 1/4 full, this is done to prevent the tank being completely emptied by running the generator.

If you get one of the big "C" units built on a cargo carrying chassis then you have the option of having more fuel tanks since the chassis will handle more weight.

navegator

[mockturtle]

The only Class C's with propane generators are those with diesel engines. I've had both and propane burns cleaner. Since I have solar now, I hardly ever need to use my generator. 🙂

[pianotuna]

What do you wish to power with the generator?

[ronfisherman]

Most Class C motorhomes have Gasoline generators if chassis engine is gas. LP generators can be found in some Diesel Class C motorhomes. The Diesel option cost more than the LP model. If you do not plan on doing a lot of boondocking the LP option is OK.