Generator year.

[Guysakar]

Hi guys,

I originally was going to get a class A mid 30 foot motor home and was basically talked out of it. I am glad I was, as a shorty (low to mid 20's) is more of what I need.

Anyway, my price range is about $15K which is putting me at the year 2000 range.

I have seen some older model motor homes which have a generator which is not very quiet and runs at a constant RPM, regardless of load, which I really, really do not want.

Do you think that that is going to be a problem with 2000 models? One in particular that I am looking at has a 4K watt Onan, but the owner is an elderly couple and doesn't know much about it.

It is several hundred miles away, so....


While I'm at it, what kind of MPG can I expect from a Class C 22-25 footer, with a slide? I gather that the larger ones get around 8 MPG highway. Will the smaller class C get much better?

Thanks for any help.

[Guysakar]

mlts22 wrote:
All inboard generators will run at either 1800 RPM (older, pressurized models with four poles), or 3600 RPM (newer gensets.) The only exception will be some diesel models that use an inverter.

Portable generators are a different story.

The key for the inboard generators is how it is installed. The Onans can be pretty quiet if the generator is shock mounted, acoustic insulation is used, pipes are vibration dampened, and an exhaust resonator is used.

As for MPG, I'd say 8-12 with a Ford E-350/E-450, 12-17 with a Sprinter chassis.

OK, that is what I was looking for. I am familiar with the Honda EU2000i, which reduces the RPM's under light load, etc...

You are saying that most motor home generators just run at a constant RPM regardless of load?

So what does that do for fuel consumption? I assume that motor home generators are nowhere comparable to portable generators, then.

I wonder why they can't use the same tech that is in the portable ones in a motor home.

So on a 4K watt Onan, you think 1/2 gallon an hour?

It might be more cost effective to just buy a portable gen and never even mess with the onboard gen, if doing a lot of dry camping.

A Honda 3000 (peak) 2800 (constant) watt gets .17 gallons an hour at 1/4 load and .47 at max load.

[KD4UPL]

It's extremely rare on even a new MH to find a generator that doesn't run at a constant RPM, their all either 1,800 or 3,600. Some of the very newest most expensive units have diesels that will vary their speed because they work in conjunction with an inverter.
With your price range of $15K you won't be buying a unit with one of those I'm sure.

[Guysakar]

crickeydog wrote:

Guysakar wrote:
1. Do you think that that is going to be a problem with 2000 models? One in particular that I am looking at has a 4K watt Onan, but the owner is an elderly couple and doesn't know much about it. 2. What kind of MPG can I expect from a Class C 22-25 footer, with a slide?

1. That question can only be answered by knowing the complete maintenance history of the generator. From your statement, "the owner is an elderly couple and doesn't know much about it", I'd say you're probably looking at a generator that has not been properly maintained. That'll cost and I'd bet it'll cost you dearly to get the generator up and running properly. The only way to know what you have in the way of the generator is to have it surveyed by a factory trained Onan repair facility.

2. "What kind of MPG can I expect"? In a word...bad. But nobody buys an RV for the great fuel mileage. Again, a lot will depend on how the engine has been maintained. You may have a gem, then again you may have a lump of coal. In great running condition you can expect 6 to 10 MPG depending. Again, the only way you'll know for sure what you have under the hood is to have the engine, drive train and entire chassis surveyed by a certified mechanic for the particular chassis you have under the hood.

Good luck.

Happy camping!!! See y'all down the road!!!:)

Hi, thanks for your reply. I wasn't talking about the state of the generator, but how the generator was designed.

Some of the older motor home generators ran at a constant rpm and did not cycle down when load was low, resulting in poor fuel consumption.

And some of the older ones are much louder than the newer ones.

[mlts22]

All inboard generators will run at either 1800 RPM (older, pressurized models with four poles), or 3600 RPM (newer gensets.) The only exception will be some diesel models that use an inverter.

Portable generators are a different story.

The key for the inboard generators is how it is installed. The Onans can be pretty quiet if the generator is shock mounted, acoustic insulation is used, pipes are vibration dampened, and an exhaust resonator is used.

As for MPG, I'd say expect 8-10 with a Ford E-350/E-450, 12-17 with a Sprinter chassis.

[the_bear_II]

Most Onan generators from that timeframe if it is a model designed for use in an RV will be quiet. My definition of quiet is if you can barely hear the generator running when you are 20 feet away it's quiet. If you are inside of the RV you barely hear the generator, you may feel a very slight vibration but only hear a muffled rumble when it's running. That's what I consider quiet.

Any RVer whether they have a motorhome, van or vehicle towing a TT or 5th wheel can expect 6 to 12 MPG. Most will fall in the 10 MPG range at best.

Also since you are looking for an RV, keep in mind most RVers start off thinking they need a small RV. However the statistics show the typical RVer over the course of their RV life will end up with larger RVs. Ususlly will go through 3 RVS until they get one big enough to truly meet their needs. The normal course is to start off with a truck camper or 15-20 foot travel trailer then move up to a 25 to 30 foot TT, MH or 5th wheel... then land on a 35 to 40 foot MH or 5th Wheel/ TH.

[crickeydog]

Guysakar wrote:
1. Do you think that that is going to be a problem with 2000 models? One in particular that I am looking at has a 4K watt Onan, but the owner is an elderly couple and doesn't know much about it. 2. What kind of MPG can I expect from a Class C 22-25 footer, with a slide?

1. That question can only be answered by knowing the complete documented maintenance history of the generator. From your statement, "the owner is an elderly couple and doesn't know much about it", I'd say you're probably looking at a generator that has not been properly maintained. That'll cost and I'd bet it'll cost you dearly to get the generator up and running properly. The only way to know what you have in the way of the generator is to have it surveyed by a factory trained Onan repair facility. Be prepared for some expensive bad news.

2. "What kind of MPG can I expect"? In a word...bad. But nobody buys an RV for the great fuel mileage. Again, a lot will depend on how the engine has been maintained. You may have a gem, then again you may have a lump of coal. In great running condition you can expect 6 to 10 MPG depending. Again, the only way you'll know for sure what you have under the hood is to have the engine, drive train and entire chassis surveyed by a certified mechanic for the particular chassis you have under the hood. Be prepared for some expensive bad news.

Good luck.

Happy camping!!! See y'all down the road!!!:)