Pros and cons of L.P. generators?

I have queried and read a lot of the generator information on the site here, but thought I would ask PW owners what their specific experiences have been.

While I have a large diesel gen set and a gas gen set on our property, our new PW is coming with an L.P. gen set. i know very little about L.P. generators. So, a few questions for those of you who have experience with L.P. generators.

- Do L.P. generators require the bi-monthly (or thereabouts) exercise that I understand the Onan gas gens need?

- Are there any specific ‘problems’ with L.P. gens?

I guess we will find out more information once our PW arrives, but thought I would see what I can learn in the mean time. Thanks.

LP generators run very clean and the fuel is very stable so they do not require the same exercise schedule as gasoline and diesel, the generator mechanics are simpler, and they have very low exhaust odor. The only real disadvantage is that runtime will be limited (depending on the size of the propane tank) compared to a diesel unit (which can use up to 3/4 of your main tank, assuming it was full to begin with.) Bottom line, for the typical 'few hours at a time' use over several days you will find your onboard propane supply to be adequate, but if you intend to run the generator for all day or days at a time then you would want the longer runtime of a diesel unit.

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It depends where you're located. I'm in a mostly very dry area of California, so I've gotten away with not running my LP generator for almost 2 years without issue. The clean propane does not gum up a carbouretor like the horrible gasoline does, so you can go much longer stretches of time between runs.
However, if you live in a high humidity area, you can't get away with leaving it idle for quite as long as I did because moisture in the windings and bearings and inner workings can do damage inside. You need to run it under load to warm it up and drive that moisture out.
Remember, these Sprinters and engines like to be used, not sit around idle to rust and rot. That's when the problems start. Use it, run it, drive it. Get it up to operating temperatures so you don't run into problems. Most issues that people experience are because RVs are sitting around for most of the year. Then people wonder when they want to use it, why something doesn't work...

I would concur with the last post. We have an LP generator on 05 P'way and much prefer it to a gas. Very little maintenance required. We live on the "wet" coast and although we go south each winter we sometimes don't leave until after Christmas, so the van is sitting outside for some pretty wet fall weather and again in spring when we return. I just run it under load for about 10 mins per month and have had zero issues all the time we have owned it. Just wish it was quieter, although the newer ones probably are.

Sheral, A timeless question. Should I gas, diesel or LP my generator.

I've got an standby gas generator for the house. Had it since early 2000's when hurricane came through Maryland. Probably less than 75 hours on it now. I 'exercise' it whenever I happen to think about it; or if a hurricane is going to strike the Texas Gulf Coast; or if there's really severe weather predicted for the Texas Hill Country (like not often); or, if my conscience bothers me....... It starts first punch of the starter & runs perfectly. The trick is: turning off the gas supply and letting it run out of gas and die. If you leave gas in the carb of most small engines they will eventually gum up if not used regularly.

I've had two ONAN LPs (2500 & 4000W) on two different Sprinter RVs. They did not get 'exercised' by the book. Like the gas genny above, I run them when I need to. I generally start them up to lay a quick charge on the coach batteries as needed. Other than that, they don't get run except to power the A/C or provide 110V power to the coach. And, that isn't a lot of run time. Our '14 View has now just over 23 hours on it. The advantage here of an LP set is that you can just shut it down and not worry about fuel gunking the carb or diesel injection and pump problems with a load of sketchy fuel.

IMHO, it boils down to how you intend to use your RV. If you are going to go out and 'dry camp' or have a special need to run the generator for hours on end.... the diesel would be your choice. It will have less of a fuel burn over time and you 'theoretically' have more fuel available from the Sprinter's fuel tank.* *Fuel available is likely much less than the 3/4 tank available.... so your run time may equal or be less than an LP unit.

If you are frugal with the use of the generator.... meaning you use it when you need to.... the LP will be perfectly fine as you are not putting hours and hours a day on it. You charge battery, run microwave & A/C unit when you need it. For 'light' work, you can use the battery powered 'inverter' system. It will provide maybe 1000W of A/C for light duties for several hours and then you have to re-charge batteries. All other systems generally run off LP (fridge & water heater) or 12V off the coach batteries. It's all about POWER MANAGEMENT and knowing and understanding your coach's systems and how they work.

Both units meet Forest Service noise requirements. So, it's about the QUALITY of the sound. Low frequency sound has more energy and travels farther than the higher frequencies. (Think of the obnoxious dude in the hopped up Honda with speakers bigger than the wheels..... yep, you can hear those base notes from a block away....and they make your whole car vibrate....) So outside, the LP's higher tone exhaust note is a little less obtrusive.

Inside, the low frequency vibes were transmitted to the coach's walls more than the vibrations of the LP's engine & exhaust. You are basically inside a drum. Just like having the Dude in the Honda in your living room. You could put your hand on the walls and 'feel the beat.' The LP not so much. LP is, then, a little more friendly inside when it's running.

Diesels stink. LP very little. And while on the exhaust..... you need to look at where the generator's exhaust spout exits from under the RV. My class B came across and exited on the off side behind the driver's side rear wheel. Perfect. The exhaust on the View extends from the generator cabinet to the rear of the RV.... probably at least 7 or 8 feet and exits below the 'bumper.' Pretty good. Some RVs, notably certain Winnebago Views dumped the exhaust out below the generator cabinet right into the 'patio' area. Pretty lame, that!

But again.... as yourself how you intend to use the generator. Is it going to carry a load constantly for a number of hours every day? Or, more of an 'as needed' supplement when you just 'gotta have' 110V AC for a shorter time? If it's the latter.... the LP would be your choice.

Back last year?, I took time and analyzed both the diesel and LP Onans available at the time, 3200 QD diesel and 4 Grand QG LP. I might not have gotten everything correct but it is 'right enough' for a decision helper.


Here's a linky to the 'analysis' I did several months ago.....

https://drive.google.com/file/d/0BzXeY3pXinO9N1JMMFo4VlpUWFE/view?usp=sharing

As above, the 'extra runtime' of the diesel is dependent on how much fuel you happen to have in your tank. If you can fill the tank just before you arrive at your destination then you will have about double or triple the runtime of a typical LP generator and tank, however if it's the end of a long day and you just want to stop and deal with fueling in the morning then you may end up with little or no runtime available.

Regarding the need for long generator runtimes in a Sprinter...

If you have a commercial or special application that requires routine very long generator runtimes then diesel is the only practical way to go. But for a Class B/small C RV the more typical use is bringing up the batteries when dry camping or some A/C when stopping for lunch and these applications are no problem for an LP unit. If you dry camp where it is extremely hot you might need all day or all night A/C and in those cases you would want the diesel, but personally I can't see why one would want to make a trip under those conditions. Plus it's not fun listening to a generator mounted in a Sprinter RV for hours and hours on end, I once tried it on a hot southern night in a Walmart stopover but it eventually became so annoying that I was better off just opening a window and using the Fantastic Fan to move air. A large Class A with a water-cooled, 1800-rpm shrouded diesel gennie that you can hardly hear is one thing, a Sprinter with a 3200QD right under your head is quite another (not to mention the social aspects of running the thing all night or all day long, unless you are pretty remote it won't make you many friends.) Basically you'll quickly find that the real-world reality clashes with the ideal.

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Maybe we need develop a decision matrix for choosing what genny to put in someone's RV??????

sheral said:

I have queried and read a lot of the generator information on the site here, but thought I would ask PW owners what their specific experiences have been.

While I have a large diesel gen set and a gas gen set on our property, our new PW is coming with an L.P. gen set. i know very little about L.P. generators. So, a few questions for those of you who have experience with L.P. generators.

- Do L.P. generators require the bi-monthly (or thereabouts) exercise that I understand the Onan gas gens need?

- Are there any specific ‘problems’ with L.P. gens?

I guess we will find out more information once our PW arrives, but thought I would see what I can learn in the mean time. Thanks.

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The lp generators are noisy because Pleasureway does nothing to insulate or isolate noise/vibration from interior. Outside noise is at best ,obnoxious. I've added the Onan silencer and super trap muffler, better but still a great deal louder. Frankly, while necessary, rude to your neighbors. Be thankful your new PW will not have the cheap,gaudy decals that deteriorate just before your warranty expires but PW does not seem interested in replacing. This does not help,but you should'nt be surprised by the noise ,now.

sheral said:

- Do L.P. generators require the bi-monthly (or thereabouts) exercise that I understand the Onan gas gens need?

- Are there any specific ‘problems’ with L.P. gens?

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ONAN says couple hours a month @ half load. Personally....I think that's old school thinking or maybe transferrance from emergency service requirements. Maybe under bizarre extreme conditions..... Sounds like needless wear, tear and fuel consumption IMHO. Just run it from time to time... Check operation as part of your pre-flight.

Haven't had any trouble with either one of mine. Although the LP regulator crapped out. IMHO...they are more reliable and have less maintainence requirements than gas or diesel....

Any engine should be run at regular intervals, especially in a humid environment, to prevent rust and condensation issues, plus keep the critters away. Onan uses the same boilerplate exercise recommendations for all their small gensets but propane-powered units are not subject to the fuel aging issues of diesel and especially gasoline (far and away the most typical causes of under-use problems) so it's not as critical for LP units, typical normal/occasional use is enough. LP units also have much simpler fuel delivery systems, since the fuel is already gaseous the carburetor is extremely simple and there is no need for fuel pumps, etc. The low maintenance requirements are why propane and natural gas-powered generators are commonly used in standby applications.

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Add a Yamaha or Honda to that matrix. I decided to not get the Onan gen when ordering my Winnebago MH. I carry a motorcycle on the back and wanted to save some weight. I think I saved 200 lbs and $2000 when installing a Yamaha gen. The gen runs on gas, but the propane was already plumed to the compartment. I modified the carb to run on both gas and propane. It usually runs on gas. The carb can get gummed up when not used. I switch to propane and it starts right up. Once it's running, I can go back to gas.

Old Crows said:

Maybe we need develop a decision matrix for choosing what genny to put in someone's RV??????

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A matrix of what to put in someone's RV is only good if you have a choice. The latest responses have been from Winnebago owners who have a choice between diesel and propane. PW does not give a choice. The diesel powered Sprinters get propane. That's all. The gas powered chassis get gas generators. There are no gas powered Sprinters that were used by PW, so that combination doesn't exist either.
The pro's of propane have been provided in the responses already.
Anyways, just thought you'd want to know that there is no choice.

Now that we have had our van for a bit, we are pleased that our gen is in fact the propane version. For the amount we will use it, propane just seems to make sense (in our case).

One of the driving forces for propane generators is that CA more or less banned small diesel generators on RVs. Saying this in a politically correct way, the people who work at the AQMD are "not proponents of diesel engines".

As far as exhaust porting, sometimes I wonder if it would be possible to vent the exhaust "up" so there were no fumes near the ground, regardless of fuel type.

HarryN said:

One of the driving forces for propane generators is that CA more or less banned small diesel generators on RVs.

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This is interesting, can you please provide a reference? I'd like to read the details.

Here are some examples:

http://www.aqmd.gov/home/programs/business/business-detail?title=voucher-incentive-program

Just do some searches on the California AQMD and diesel engines. I am not saying that diesel engines are perfect, but these people are politically focused on the issue, which is why they jumped all over VW so hard.

Essentially what has happened, is that the cargo ships come in burning heavy fuel oil, and we have to offset the particulate and NOx pollution by increasing the regulations locally. The oil refineries took a huge hit on allowable emissions. We can't even have a fire in our fireplaces for Thanksgiving or Christmas so that cargo ships can use heavy fuel oil. It is a really screwed up arrangement.

The methods of enforcement have driven companies away. To give you another example, they came up with a VOC rule called "the 5 lb rule". If you emitted more than 5 lbs per day of organics (example 5.2 lbs, about 1 gallon ) then you had to eliminate 99% of the emission, no matter how dilute and no matter if the plant covered 100 square feet or a square mile. On the other hand, if you emitted 4.9 lbs, you didn't need to do anything. It only applied to industrial companies while, dry cleaners and bakeries, which routinely emit more than 100 lbs per day, were exempt.

It is all just done to charge fines and build fancy office buildings.

Ok, but I don't see what that reference has to do with banning diesel generators on RVs.

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HarryN said:

We can't even have a fire in our fireplaces for Thanksgiving or Christmas so that cargo ships can use heavy fuel oil. It is a really screwed up arrangement.

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Well, don't think California is the exclusive bastion of craziness like this. In Seattle, we aren't allowed to have bonfires on the beaches because of the carbon emissions. Never mind that despite being one of the the computer capitols of the world (Microsoft and Amazon), we can't install computerized traffic signal management to minimize the carbon emissions of untold thousands of cars stalled in traffic--even though several much smaller communities seem to have figured out how to do it.

Rock Doc

Rock Doc said:

Well, don't think California is the exclusive bastion of craziness like this. In Seattle, we aren't allowed to have bonfires on the beaches because of the carbon emissions. Never mind that despite being one of the the computer capitols of the world (Microsoft and Amazon), we can't install computerized traffic signal management to minimize the carbon emissions of untold thousands of cars stalled in traffic--even though several much smaller communities seem to have figured out how to do it.

Rock Doc

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We have the computer controlled traffic lights here. It turns out that the police like to play games with people at night and leave someone sitting there at a red light, with virtually no one around, to see if they will eventually run it and they can hand out a ticket. I have sat through some pretty long light cycles, and so have my kids. Kind of annoying.

The system is also less reliable than traditional timers, so while it helps sometimes, it isn't unusual for it to go down, and then we are all playing "artificial stop sign" at intersections with 3 - 5 lanes in each direction, plus 1 - 2 turn lanes. It isn't always that easy to figure out when it is your turn to go.

smiller said:

Ok, but I don't see what that reference has to do with banning diesel generators on RVs.

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Hi, you are just as good at internet searches as I am. The link is an example of CA AQMD pushing on methods to reduce diesel use in small engines, off road use, etc.

Sorry but I cannot dig through every law and agency rule - there are 1000s per year and I am not a lawyer.