What are some ideas in trying to decide between the two ?

consider current events, alot of people are reporting diesel shortages ahead of gas because stations stock more gasoline than diesel.

diesel.

you can store the fuel forever. you can also use home heating oil and all sorts of home made fuel mixtures to get around.

Semi's are parked everywhere. You have a hand pump. You get your tank filled
SHTF no brainer.

I went with gas because I had two other vehicles with the same engine and transmission.
But I will be doing a trade-in with fuel efficiency being the big factor as I want range on my BORV.
If all goes well I want one of those MB diesels pulling my jeep.
I get 4-5 mpg in mine with a 6.8 v10 even with a 50-gallon tank you're not going far.
My neighbor has a sprinter that he gets 16mpg towing.

That's brilliant!

not really.
I would not count on being first to steal from a parked semi.

I want something like this built in so that I could pull up next to a tank and grab it fast.
I don't want to spend a long time or be distracted. Pull up open hatch drop hose in tank flip switch and then keep an I on my surroundings while it pumps.

In and out in 5-10 min.

It is an interesting idea but if things get really bad how many scenarios are you going to encounter where a vehicle is abandoned, unattended with fuel in it?    I would suspect that most of our drivers would use their trucks to get home and then get their families out.  

This reminds me of the guys that pick a caliber because it is used by .mil or LEO.   They say that they can forage from abandoned LEO vehicles etc....   Sorry, but if things are bad then I cannot imagine a vehicle with ammo abandoned willingly.   And if they are abandoned (even unwillingly) then they would be picked over VERY quickly.  

And I suspect that you did hear the story about the looter that was shot in the head when he discovered that the abandoned house he broke into wasn't actually abandoned?  

Planning on being able to efficiently steal fuel is a terrible idea on multiple levels.

Gas is still more common. parts are more readily available and they are easier to work on for most people.

It's not the plan just one of many backups.
Currently, we don't travel further than we can get home with what we carry.
1200 for the pickup and 1000 for the RV with the jeep.

The problem with new SCR diesels is that if/once your DEF tank runs dry you're dead in the water.

Have a pickup and pull a camper.

You can ditch the camper if need be, and you can create a stationary home base and not have to take the RV every time you are out.

99.9% change your bugging is civilized

Buck, Harbor freight has a similar pump at ~ the same price.

We're using one now to pump insecticide and they aren't self priming.

Gas (pros)

cheaper engine, cheaper fuel, cheaper repairs
more reliable (vs modern EPA screwed diesels)
gas can be found nearly everywhere
can share stored fuel with gas vehicles

Gas (cons)

less efficient
less range (vs same size fuel tank in diesel)
more difficult to store (flammible vapors)
less power and less payload/towing (usually)

Diesel (pros)

pulls loads with ease
fuel stores much easier (transfer tanks in pickups, etc.)
more range
more efficiency
reliable (if EPA crap removed)

Diesel (cons)

more expensive to buy
more expensive repairs (if out of warranty)
more expensive to make reliable (EPA equipment removal)

Overall, I think having an emissions deleted diesel with an auxiliary fuel tank is the best option, but it's also very pricey.
If you're not made of money, a gas option will work "out of the box" with no problems, however you will have to stop more often to fill up, and will have to rely on gas stations always having fuel.
Having an EPA equipment intact diesel is a risky option, and can leave you stranded when it's inconvenient or dangerous.

Size of rv will often determine engine choices.

Smaller ones don't have a diesel and bigger ones don't have gas.

If playing with common "rv" stuff then watch quality of assembly.

If you want a bug out RV...

Try to find something older that has the 12 valve Cummins 5.9L.  I don't know if the ones they put into motorhomes ever came with the Bosch P-7100 injector pump but that would be the one you want if you can find it.

It is completely mechanical. Extremely reliable. And pretty good on fuel too. Newer diesels all have tons of emissions crap, electronic everything.. etc. I would not buy a new diesel engine.  I literally spent over a year finding a good dodge truck with that cummins engine in it basically just for that engine. In a dodge 2500 empty I get 19-20mpg with that truck and I have done some mods to the injector pump for more power. Obviously in a motorhome you would not get that kind of mileage but there is something to be said for the simplicity and reliability of that old engine. As long as you can get it started it will run.

I saw today on my local craigslist a mitsubishi fuso that had a custom camper on the back of it. Pretty sweet looking little rig. I'd take that over any RV anyday if it was going to be something to "bug out" with.

Here in Texas Diesel was generally easier to find during Harvey.

Siphoning from abandoned cars was quite common last week during Harvey when many stations were shutdown or closed.

Trains also run on diesel.

So do the back-up gens on the shitter lift pumps.

I'm curious what kind of mad Max bugout is being envisioned where it is acceptable to steal....

It's never acceptable to steal.
But any scenario where there are abandoned trucks and trains sitting around with no drivers or sounds like a virus has wiped out a good chunk of the population or a nuclear war has broken out and EMP has knocked out most of the vehicles and everyone else has fled on foot. Or both at the same time! And zombies don't forget zombies.

I sure hope I'm not vacationing when this happens but if my immune system keeps me alive and my RV keeps running I will not hesitate to scrounge for fuel to get home.
Oh, and If we do die please help yourself to our shit if it keeps you alive another day.

Being prepared for the worst case is called being a prepper.

Yes I do realize it for talking an actual apocalyptic type scenario take whatever resources you can get ahold of because the owners are most likely dead. However that said 99.9% of any evacuations are going to be civil and less zombies. that's where the practicality comes in. I still like the idea of two separate units tow vehicle and a recreational trailer because you can drop the trailer and make Basecamp or if you absolutely had to you could drop the trailer to increase your range of driving. That and a motorhome that sits around and almost never moves is going to have a lot of mechanical problems when you all of a sudden put it on the road. If your total vehicle is something that is driven regularly it is likely to keep driving regularly when you need it to.

My opinion only of course.

+1.

Plus, the tow vehicle can carry extra gear/supplies.

I considered going diesel but once I realized the downside to the SCR engines because of the DEF issue I went back to gas.  And the newer gas engines (Ecoboost) offer pretty good power and mileage within their designed performance range.

What is the RV?  We have a 36 foot RV and its a pain in the ass to drive around and get to places.  I cannot even imagine taking it for a SHTF vehicle.

My RV is 23 feet long, drives easier than my F350, and has a tighter turning radius.

It depends if you plan to use the RV for frequent travel. If yes, a diesel version, IMHO. is a better choice because it's a lot more fuel efficient, more durable and has a much higher resale value (higher initial cost as well).
If you are looking for an older RV that won't "break the bank" and will only use it for occasional camping, then a gas version is probably a better choice. They are a lot cheaper to buy used than diesel powered RVs. Gas engines usually have weaker transmissions and generally don't last long. I've seen transmission and engine failures at 20,000 miles.

As far a diesel availability goes, I think it will be a lot easier to obtain during SHTF. Usually when fuel supply chain has an issue, gas is first to disappear. You can also always barter for diesel much easier than gasoline. Many commercial trucks or even locomotives run on diesel. When people get desperate, during a real SHTF, they will simply steal diesel from where they work and barter it for food or anything else of value.

As mentioned in previous threads, look for an older RV with a 5.9L Cummins, all mechanical diesel, without the modern particulate exhaust filter that requires DEF fluid. I've seen some nice class A RVs, with a diesel pusher engine, for sale at around $20,000. November through late February is the best time to look for deal.
Many people who travel a lot or live full time in their RV, choose to have a diesel 4x4 truck with a truck camper in the back. This allows them to park just about anywhere and to go places where no other regular RV can make it. Some guys buy 4x4 diesel vans and convert them into a small camper RV. Obviously, it only works for a small family or a single individual.

You may not find "fuel", but almost every car will have transmission fluid and motor oil which after being filtered can be run in some diesels.  Also add in vegetable oil, used motor oil, peanut oil, kerosene, etc.  All will need to be prefiltered and some will need to be heated to run properly - none of which is a big problem if you prepare.

As to the OP's question, as others have said, newer diesels do not make great bug out vehicles b/c of the EPA crap (e.g., urea tanks).  Older diesels are the way to go, such as the already mentioned 5.9 cummins or a 7.3 Powerstroke.

Yet another aspect is - how much work are you willing to do, OP?

If you get a diesel get something without a computer, like a GM 6.2l, Ford/Navistar 6.9l/7.3l, or Dodge/Cummins 12V 5.9l. The Navistar engines are incredibly easy to work on, short of a windowed block there's nothing you can't repair on it on the roadside using a toolkit that fits under the seat. They'll burn kerosene or jet fuel (not very well in the summer due to low viscosity), heating oil, or any oily liquid.

Stealing semi fuel is like stealing a horse with the same consequences

I have an 02 Excursion with the 7.3 - it has a computer. I put a chip in it to get a nice power increase.

I don't know if you have started shopping yet but you will also find diesel RVs are a lot more expensive then gas.  I think in our model when we bought new it was another $100k to move up to a diesel pusher.

Diesel.  For the reasons listed above. I just sold a 95 34 ft diesel pusher ( Cummins 12v and Allison transmission)that got 10 mpg and had an 80 gallon fuel tank. Would haul up to 6000 lbs of trailer. Sold it for a newer toy hauler.

Driving through mountains with a gasser sucks.

What kind of rv are we talking about