LP Generator Run Time on Class "C" RV LP Tank

TrailerFool · 08-21-2008, 01:49 PM

Any REAL WORLD experience would be helpful...I'm attempting to figure-out the pros and cons of having a LP generator versus having a gasoline generator in a Class "C" Winnebago. Does the LP tank empty more quickly. If so, how much more quickly? How long can I expect a LP generator to run on a full tank of propane (assuming Air Conditioner is ON and intermittent use of other electrical appliances)? Is the somewhat lower wattage output of the LP generator significant?

TrailerFool · 08-21-2008, 01:49 PM

Any REAL WORLD experience would be helpful...I'm attempting to figure-out the pros and cons of having a LP generator versus having a gasoline generator in a Class "C" Winnebago. Does the LP tank empty more quickly. If so, how much more quickly? How long can I expect a LP generator to run on a full tank of propane (assuming Air Conditioner is ON and intermittent use of other electrical appliances)? Is the somewhat lower wattage output of the LP generator significant?

skigramp · 08-21-2008, 05:21 PM

This webpage shows some of the information that you are looking for

Onan LP Genset

I believe that most LP tanks can be filled to 80% of their nominal capacity ... so if you have a 20 gallon LP tank ... the most it can contain is 16 gallons of LP. One of the disadvantages of LP gen sets is that you can't bring a 5 gallon can of LP to you motorhome when you run out ...

You need to check to see if the amperage is sufficient to run the air conditioning unit ... make sure that the gen set has enough power for the start up ... AC always have a large load at start up ...

TrailerFool · 08-21-2008, 06:08 PM

Hmmm....is that what class "C" Winnebago/Itasca Diesel motorhomes come with - a 20gal LP tank? Is that a dedicated tank for the LP generator (separate from the other LP tank(s)?

RedT · 08-21-2008, 06:20 PM

I think the real answer to your question lies in your usage - and the difference in cost between propane power and gasoline or diesel power genset.

For me, I seldom use a genset, therefore the ~$4,000 extra cost for the diesel generator did not make sense. Having said that, diesel or gasoline has more BTU's than propane. A propane genset running under a load will burn approx 1 gallon per hour. My experience with the propane genset is that it starts easily, provides plenty of power and has been trouble-free for five years.

autofish · 08-21-2008, 07:01 PM

LP gensets require less maintenace because lp is a dry fuel but have about 10 to 20% less watts for same gen on gas. Fuel usage will depend on gen size and load. Typical RV gensets use from 1/3 to 1 gal per hour. If genset is mounted in rv makes sence to run on rv motor fuel gas or diesel hope this heps.

porscheracer · 08-21-2008, 08:34 PM

I would only consider an LP generator if I didn't plan to use it - ever. It would be handy as a backup - but running full time at high load on a typical class C LP tank (16 gallons usable is about right), you'd be lucky to get 24 hours' use. Whan you're out of propane, you're out of everything - no electricity, refrigeration, cooking . . . nothing but gas to go get more propane.

I prefer diesel, but they're only available / practical if you have a diesel MH. And the only diesel C Winnebago makes is the View. As a comparison, the 7500W diesel in my Vectra uses about 10 gallons a day, full time boondocking at 90+ degrees, with the AC going as hard as it will go - plus all the other normal living usages. In other words - easy to make a full week on 4/5 of a tank of fuel (before the low fuel shutoff) - and by that time we're out of water and the holding tanks are full.

TrailerFool · 08-22-2008, 06:01 AM

I wonder why Winnebago's Diesel "C" motorhomes (I'm only looking at used models) are only available with an LP generator. It seems like a diesel generator on those models would make perfect sense!

porscheracer · 08-22-2008, 08:45 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TrailerFool:
I wonder why Winnebago's Diesel "C" motorhomes (I'm only looking at used models) are only available with an LP generator. It seems like a diesel generator on those models would make perfect sense! </div></BLOCKQUOTE>

They were available with diesel generators. However, since the majority of C's sold are dealer stock items, the dealers are reluctant to add $5000 or so to the price for the diesel over the LP. There's always the (not inexpensive) option of retrofitting.

TrailerFool · 08-22-2008, 07:50 PM

Is it possible to add a second LP tank to fix the LP capacity problem related to the LP generator?

skigramp · 08-23-2008, 02:55 AM

People who stay in one spot for extended periods of time use one of these

LP extended stay adaptor

You could use one of these with a small LP tank like you have on your BBQ grill

Darryl · 08-23-2008, 05:32 PM

The LP generator is a good unit, and works well. You might also avoid some the the carb problems that the gasoline units can get from not being exercised regularily. However, it is a big issue if you dry camp. About 1 24 hr day or slightly more, depending on your usuage, is about all you will get with most LP tanks.

This is a big problem if you go to dog shows like me. Most shows are 3 or 4 days. This is a well known issue amongst the show people and also the reason most opt for either gasoline gen sets or diesel (if the coach is diesel). Unfortunaley, I have a diesel coach which I love, but it came with an LP genset which I hate. As a consequence, I only go to dry-camp dog shows in early spring or late fall, so I have a small, limited time that I need air conditioning. If I don't need A/C but 3 or 4 hrs a day, it works out just fine.

porscheracer · 08-23-2008, 06:16 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by skigramp:
People who stay in one spot for extended periods of time use one of these

LP extended stay adaptor

You could use one of these with a small LP tank like you have on your BBQ grill </div></BLOCKQUOTE>

A small (20#) LP tank would run a generator for maybe 4 hours, on moderate load. Rather an expensive way to go. If you're going to be using it much, I'd think a retrofit would be more cost effective in the long run - never mind the convenience.

BTW - and totally OT - skigramp . . . we were through your fine town about 2.5 weeks ago, after staying a couple of nights at Fond Du Lac, and on the way to the Keweenaw.

Jeeperrmartin · 10-02-2008, 04:52 AM

I have a a lp generator on diesel coach. I have spent over $10 an hour to keep it running. On the frits again. I don't run it that much because there is always something wrong with it. I will run it every month even if we aren't using it, but most of the time it doesn't work.

My solution is, I carry a Honda 2000 watt generator with me that we have probably well over 5,000 hours on it. I keeps the batteries topped off, will run the microwave if tv is not on. We never run the AC with it, but turn on all the exhaust fans, open the windows, and have a Vornado fan running in hot weather. Will usually keep the coach within 5 degrees or less of outside temps. This would be 5 degrees warmer than outside. We just learned to live with the temps.

We dry camp close to 6 months a year.

Honda generator will usually give us 10-12 hours on a gallon of fuel, also extremely quiet. You can stand right over it and carry on a conversation.

tderonne · 10-02-2008, 07:17 AM

"Class C Winnebago Diesel"

Do you mean Dodge Sprinter based stuff? Or perhaps the rare Ford Powerstroke equipped F350/450 one?

2008 View/Navions offered a diesel generator as an option. No diesel was available before that on them. I suspect the lack of a small diesel generator also means that the Ford based ones would all be LP generators.

FrontRangeRVer · 10-02-2008, 07:21 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TrailerFool:
I wonder why Winnebago's Diesel "C" motorhomes (I'm only looking at used models) are only available with an LP generator. It seems like a diesel generator on those models would make perfect sense! </div></BLOCKQUOTE>

Please double check on that. I believe that you can get the diesel generator as an option on the Dodge based Sprint Chassis.

For us, having a propane generator would be a deal killer.

porscheracer · 10-02-2008, 11:48 AM

It's a matter of usage - as I've stated. We have an Onan Quiet Diesel 7500 on the Vectra, and it has ~1600 hours on it (in ~3 years). Cost of operation is approximately 1/2 gallon of diesel an hour, plus oil and filter changes - about $0.50/hour netted out. It is powerful, flexible and quiet. The only downside is it still smells like a diesel.

Our '08 View has the optional Onan 3500 Diesel. It is nowhere the unit that the QD is (nor the price). It is not as quiet as any of the premium diesel or gas (Honda), more along the line of a traditional 4KW gas MH generator (although significantly quieter than our 6500 Emerald on the LQ trailer). I'd have no problem running the Vectra one in a moderately quiet area - like a parking lot - not so the one on the View. It does, however, seem to only use about a quart an hour of fuel.

Why do we need a big genset? Over 50% or our "boondocking" is at sports car races, on paement in the paddock area, where absolutely no electricity is available. The ambient air temperatures range (frequently) into the 110* degree range, and there is NO shade. Alternatively, we may be in any sort of weather

We are on site for anywhere from 60 to 150 hours at a time. So, everybody who touts diesels isn't crazy!!

tderonne · 10-02-2008, 05:16 PM

Warning off topic...

I hear Topeka does have quite a parking lot to run that generator in. After 12 years of RunOffs, Topeka just didn't seem worth it. Road America....hmmmm....

Tim
(HP Festiva sitting in the garage)

porscheracer · 10-02-2008, 06:05 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by tderonne:
Warning off topic...

I hear Topeka does have quite a parking lot to run that generator in. After 12 years of RunOffs, Topeka just didn't seem worth it. Road America....hmmmm....

Tim
(HP Festiva sitting in the garage) </div></BLOCKQUOTE>

Yeah - all 200 hotel rooms in Elkhart Lake should be pretty busy next year.

chasfm11 · 10-02-2008, 06:19 PM

We have an LP genset (Onan 6.5K). It came with our used Class A. It runs both A/C units (13.5)just fine but as pointed out, it will suck about 1 gallon per hour if it is really hot outside. Most of the time, we use the genset to power just one A/C while driving in hot weather and it runs about 1/3 gallon per hour. We have 38 gallon take so, under most conditions, we can use both A/C for about 30 hours continuously on one tank.(remember it is 80% fill).

If we were locked in for several days in one place, the Lp genset would be a pain. I'd prefer diesel, where I could jerry jug in fuel if I needed to. We haven't really had that condition in the 4 years we've had the RV so the only annoyance is having to stop where they have propane and diesel on the road. Flying Js are great for that. Without those, sometimes we have to hit towns to find a propane distributor and some of those lots aren't very big - for a MH and toad.