efficiency/effectiveness

A fridge will run out a battery in a day or so, maybe two ... not effective to run Fridge on battery for very long.

I'd keep it on propane unless you have elect hook ups. We run fridge on battery while we travel a long distance, and keep battery charged as we drive. Battery alone does not usually keep the fridge cold enough even when driving, especially the freezer ... we ran 8g wire direct, and it's still not enough.

The 12v option is a keep cool, it does not do the same amount of cooling as lp or 120v

Run it on lp, unless you are out of lp
It really not good for much, except a emg backup

It will suck your batteries down fast, 10 amps or more continuous draw

Not all that much to go on. I was able to see that a Pleasureway Ascent is a Sprinter based Class B motorhome. OK, but their website doesn't tell us which fridge it has. That said, since it's a motorhome (as opposed to a small camping trailer, popup, A-Liner, Hybrid, etc. Rather a Fridge that runs on a 120VAC heater (powered by Shore Tie, Generator, or Inverter), an LPG Burner, or a 12VDC heater that should only work when the Sprinter's road engine is running. So if it's wired correctly, only the 120VAC and LPG options are available when the Sprinter isn't running. Try to use "battery" overnight and you actually should get NO cooling.
BUT!!! Remember this: Most RV fridges like Norcold N6xx and Dometic RM26xx use 12VDC to CONTROL the 120VAC and the LPG modes. If your Coach/House battery is down (probably 10-11VDC or less), it won't activate the 120VAC element or the LPG burner.
www.bryantrv.com has a lot of tech documents to help with troubleshooting, but you have to know the appliance Make and Model.

To answer your question: use propane. It will provide more cooling.

The 12v option is for when you are towing a trailer or driving a motor home. If used on the RV's battery when nothing is charging that battery, it will run the battery down in quick order.

It is used for maintaining a cold temperature, but is not powerful enough to cool one that needs cooling.

Hi,

My 12 volt fridge works well--if I'm plugged into shore power. Otherwise there is too much voltage drop on the wiring and so the fridge warms up. The "power" changes with the square of the voltage. So 34 amps @ 12 volts (144) is quite a bit lower than 34 @ 13.6 volts (185). That's about 23% more @ 13.6.

There is little difference in cooling on propane or 120 volt.

I don't find any difference between the cooling for 12 vdc, gas or 120 vac on our Norcold. Ours is new and we can only run on 12v when the engine is running, but we can put in a tray of water in the morning, drive all day, and have ice for cocktails when we set up in the evening. That pretty much meets my requirements for cold :).

Dave

Propane may cool the refrigerator down faster from warm, but once the freezer and frig are down to temperature, it shouldn't matter which you use, propane or electric to maintain the cold temps.

To all who responded here...thanks very much!

We've just retired and are intending on doing a lot of travelling over the next decade. If any of you are up our way (Tobermory, Ontario) look us up, we've got a place for you to park and hook up!