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harvnlois 06-24-2019 06:56 PM

Vegas AC While Driving
Hey All,
We are still in the early stages of trying to determine which make and model are for us. To that end, we have put a deposit on 1 weeks rental of a 2019 Vegas 27.7 for mid August.
In discussion with the owner, we were told that since it will be hot, we will probably want to run the roof AC while driving, and to do that we would need to run the generator. Of course, that would mean many hours charged for excess generator use.
Is the owner correct? Does running the roof AC while driving require running the generator? Is this just on the Vegas, or across all Class A motorhomes?
Look forward to all your helpful comments.
RVer Wannabes
NW Arkansas

MJC62 06-24-2019 07:28 PM

The roof A/C on all motorhomes Class A, C or B runs off 120 volt ac current. That requires the generator to operate while off shore power. If it were me I would see if the dash a/c was sufficient to cool the coach while traveling before running the roof ac. Besides the genny hours adding up running roof a/c will burn more fuel. To help with air flow we always open the farthest rear roof vent to allow the cool air to flow through the motorhome.

Oneilkeys 06-24-2019 07:43 PM

You can use the search function to see all the mods that have been made to the Axis/Vegas to cool down the front. I have added window tint to the top side windows, a curtain that runs behind the chairs to keep the cold air in and two clip on fans mounted at the top corners of the windows. In addition I installed a ďpillowĒ in the front vent. For most conditions we have not found it necessary to run the roof A/C down the road. However, with that big front window, when heading west into the sun on +100 degree day, it can get hot.

turnerdh 06-24-2019 07:57 PM

On our Las Vegas trip last summer, we found that running the roof and cab a/c to our desired temp then just using the cab a/c to maintain the temp was enough while on the road. We have a 25 foot Siesta.

bevedfelker 06-24-2019 08:02 PM

I have a 2015 Vegas 24.1. We lived (and used it) in FL from Aug 2015 through Jun 2018. In all the driving we did in FL (and up and down the east coast in summer) we never ran the generator and used the roof AC. The engine driver AC set on MAX A/ was always enough cooling for us (and my wife likes it really cool when we are traveling). The RV has over 19000 miles and most of that was driven in FL, GA, SC, and NC.

And the windshield on the 2014 & 2015 Vegas/Axis was way bigger than the ones in the 2017 - 2019, models. Our windshield makes you feel like we are in a fishbowl.

The Gritz Carlton 06-24-2019 08:04 PM

Three things you are doing right...trying one out before you buy, renting it in August...(if it works in August it will work anytime)...and thirdly, understanding you most likely will need to run generator full time in the summer to keep coach cool. It's the nature of the Class A Gas Beast. Many have made significant modifications to the cab insulation, engine box insulation, window modifications, etc. to cut back on the heat up front. Some to the point of hanging curtains just behind the front seats to keep the cab cool with just the dash A/C (if it works correctly). With this being a rental unit...chances are these modifications have not been made. Play it safe and plan on the additional expense of running the generator a lot while driving. Not trying to be negative here...just factual...and I base this on what owners of these units have said...not personal experience...isn't this what the owner has already warned you about?. This is one the biggest reasons I didn't buy a Class A.'s the perfect storm as far as what a motorhome floorplan should be. It's all about a quality cab...or the lack thereof.

Chance 06-24-2019 08:07 PM

Since itís a rental motorhome, and you canít make upgrades, the only other thing Iíve seen done, besides running generator, is to install a temporary curtain behind the driver and passenger seats ó much like a bulkhead. That can help by reducing the size of the cab to be cooled, but comes at a price. For starters it makes cab area feel enclosed, and also doesnít work with other passengers or pets in back. Extra cooling in cab means less for the rest of the coach.

I tried it once on my Class C by hanging a clear curtain down from bed area but it wasnít worth it because the A/C was good enough, so I didnít even drive with it that way. I did use it to reduce A/C load once parked, but thatís a different problem than youíre asking.

Mr Sunshine 06-24-2019 09:13 PM

Kudos to you for doing the rental route before deciding on a purchase. The answer to your question, it depends. You didn't say how much you will be charged for generator hours.

Our dash air does great on the highway, not so good when idling. We run the generator when we start out, if the coach is too warm. If you are more patient (and frugal), you might just tolerate being too warm until the dash air does the job. It was the same with our previous 33' Class A. More space meant more help from the roof A/C.

For us, we would pay the charge for the generator as needed. Gas use is around a half gallon per hour, so not a big factor. Now if you are crossing Death Valley, you will likely need both.

Long & Winding road 06-24-2019 09:56 PM

yeah, kudos for trying it out before you purchase one. :thumb:

Do what they said above and expect to run it "some". You Need to be confortable and enjoy yourself.

How much to they charge "per an hour" of generator use? Do you give you like 10 hours free with the rental?

Once your in a camp ground (with electic hookups) you can cool down that RV and NOT be using the generator.

Plus cool down the RV real good before you leave your camp sites so it wont take much to keep it cool (at least for a couple of hours before the heat really kicks in).

Let us know if you have any more question. Many folks here have many years experence with the same or simular RV.

TurnerFam 06-24-2019 11:26 PM

I think for a single week's trip, you won't want to do anything or certainly spend any amount of time or money making any 'changes'...just use the coach as it is designed and see how it works for may find that the normal vehicle air conditioner will be just fine, or you may find that trying the roof a/c with the generator to see how it works will be a nice trial, in case you need to do that after you 'buy' one....

we travel a lot, and hardly ever run the generator just for the a/c unit, and our coach is 35' with two roof airs.... it might get warm in the living areas behind the driver and passenger, but that's just part of traveling in the heat of hot summers with lots of humidity... you can certainly also easily plug in floor or table top fans if you have an inverter in your RV, which adds a lot to the 'coolness' of the RV while traveling.

Don't sweat it! A lot of people may 'say' things that might scare you, but getting out there and finding out yourself is the best course - some folks like it really 'cold', while others are very content with 'cool', while some of us others just open the windows and let mother nature do her job! : )

ducksface 06-24-2019 11:36 PM

Due to owner knowing an inadequacy(in his view) tell owner to step up and trim the generator fee to compensate for his faulty(in his opinion) rental equipment.

Then try it both ways. It won't matter if the owner admits to the deficiency and mans up or're test tests.
Then decide.
Your experience is the only opinion that carries any weight.
It's nice to ask opinions, it's required that you sort them as they'll suit you.

As far as extra fuel used.
Do the math and see how little it affects mpg. It's surprisingly little.
You Might come up with 120mpg to run that generator on YOUR RV when you buy one.

16ACE27 06-24-2019 11:38 PM


Originally Posted by TurnerFam (Post 189490)
while some of us others just open the windows and let mother nature do her job!

We used to call that "255 AC" in the days of the fuel crisis: 2 windows open at 55 Mph.

TurnerFam 06-24-2019 11:46 PM

255 AC, nice : )

also, you'll find that the generator uses barely noticeable amounts of fuel...hardly worth the concern or fear...use it as needed, don't when you don't need it... it will hardly matter either way.... when you travel a lot, you'll find that a little use of the generator is not going to greatly impact fuel is very, very efficient - plus, you'll probably be plugged into Shore Power most of the time you're parked, so the outcome of any use of the generator is negligible.

jannnda 06-24-2019 11:55 PM

We travel with three Irish Setters. Two of them are in crates where the dinette was. We have fans above each crate. The other dog rides on the bed in the back of the MH. Living in Houston TX it can get really hot so most of the time we do run the generator and both roof A/Cís and the dash A/C. If its cooler out we can run the dash A/C and the fans. May wife tells me itís all about the dogs.

Muggs 06-25-2019 12:14 PM

On my Vegas 24.1 I run the generator for A/C only when we have the Grandkids with us. If it just the 2 of us, dash A/C is good enough. Dog gets tethered to passenger seat pedestal. We will on occasion run generator for a bit prior to stopping to pre cool unit. when we are heading to single day race will exercise generator on way to track if unit has sat for 2 weeks.

In 3 years of ownership, we have 388 hours on generator. Had 74 hours when we purchased unit. I have a $320 Champion RV ready generator on racecar trailer that is used at track and it likely has upwards of 3000 hours by now. From inside RV it sounds same as internal Onan.

Realistically, the extra fuel use is negligible in grand scheme of things. I cannot see generator use being a major restriction unless crazy pricing, especially a rental in August.

Test everything completely and enjoy the trip and the experience.

Had we tested, we likely would gone larger. Once we learned how to apportion storage, we are very happy with size we have. We both quickly learned carrying 14 rolls of TP, 16 rolls of paper towels, enough dispoable plates and dinnerware for a couple decades everything fits great along with racecar stuff. That is another learning curve.

The ability to park virtualy anywhere and fuel at a regular pump is wonderful. Stopiing at rest stops for pup and having own restroom is really appreciated by the wife. The ability to use unit with slides in is a major plus.

Best of luck and enjoy the trip.

The Gritz Carlton 06-25-2019 12:27 PM

I met a mobile mechanic a couple years ago as he was making his way through a CG in Port Canaveral. He said 99% of every issue he sees with all makes and models of campers is directly related to three things...extreme overloading, lack of preventative maintenance (also failure to see arising issues from lack of regular inspections) and improper tire inflation. The first thing he checks on every service call is tire pressure...9 out of 10 have serious differences in pressure. Pack lightly, do a daily walk/look around and check tires often.

Bob Denman 06-25-2019 12:29 PM

I like the idea of adding a temporary curtain behind the front seats, and opening up the windows and vents!
Good luck: please let us know how your "rental adventure" works out for you! :thumb:

jannnda 06-25-2019 12:34 PM

I agree with the tires. On my class A they are not like that on my car. My car change but not that often. On the MH the psi changes all the time. Preventive maintenance is something I done for every so not an issue for me.

Chance 06-25-2019 01:19 PM

On rentals weíve always been charged for generator use on an hourly basis. For the most part weíve only used generator to power microwave for a few minutes during the day, so it hasnít added up to much cost ó certainly negligible compared to rental costs and gasoline.

The only time I recall running generator for A/C while driving was while climbing out of Death Valley eastbound when old motorhome started to struggle a bit and started to overheat a little. I turned off dash A/C to help engine a tiny bit, so ran the generator and roof air conditioner for maybe an hour.

With Cruise America rentals if you run the generator all the time while driving, it could add up. On a 5,000 mile trip you could see about 100 hours or more of generator charges. I donít recall hourly charge but itís significant.

Long & Winding road 06-25-2019 07:01 PM


Originally Posted by TurnerFam (Post 189490)
we travel a lot, and hardly ever run the generator just for the a/c unit, and our coach is 35' with two roof airs.... it might get warm in the living areas behind the driver and passenger, but that's just part of traveling in the heat of hot summers with lots of humidity... you can certainly also easily plug in floor or table top fans if you have an inverter in your RV, which adds a lot to the 'coolness' of the RV while traveling.
: )

Wow, thats great. My wife like it cool while we travel .... so if its like 85 deg (or more) outside I have the Genny on and AC running full blast. I will shut it down for a few hours if its a cloudy day (and the dash air is holding its own) or after once it turns dark while traveling.

Or if we are taking a long work break I will crank it up and shut the Chassis engine down.

It was cool on our last trip (two weeks ago) and the highs were only in the 70's so we never ran the house AC unit. :thumb:

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