If you are wanting to go for extreme horsepower, Banks Power has a "double-shot" water/methanol kit for the Ford V-10, which pretty much does the same thing as nitrus, adding 150-200 horsepower without tuning.
Definitely not something to do if a vehicle is under warranty, and I've not read about how this affects the life of a V-10 long term (and I doubt it doesn't help things). However, if one feels the Ford V-10 isn't up for the job, this is a solution. Of course, how the transmission and drivetrain can take the added torque/HP without grenading is another question.
I did have my LP gas cover go flying... but that was when opened it, and found that over the summer, it became an apartment complex for a hive of wasps. Thankfully it was cold weather, so they were not active. My reaction tossed it a good distance for something as un-aerodynamic as that cover.
Since you want a toy hauler, I'd highly recommend you consider a fifth wheel. You can tow a longer rig, and it is a lot easier to pull than a travel trailer.
As for slide-outs, make sure they have an awning/topper. That will help with most of the water intrusion issues. After that, change out the rubber wipers every 5-6 years, as they rot just like tires do.
How many times have you been rear-ended over the past five years?
How about the past ten years?
Yes, it CAN happen. However, what are the chances it WILL happen?
Yes, I have heard all about "It is just good insurance!" Unless, of course, whoever makes the statement doesn't agree with what you want to do, then "good insurance" has nothing to do with it (whatever "it" is...)
Then again, those who wonder why anybody would need that much propane have a point, too.
Of course, the bottom line is: It is YOUR rig, do what YOU want with it. If I see a rig that worries me, it behooves me to stay as far from it as I can!
Oh, yeah, the base question: While it might cause a huge ball of fire, I doubt if it would be a "mushroom cloud".
I was using a bit of hyperbole on the topic line, but it did get the point across. Since I do boondocking in the winter, having additional propane is a good thing to have. My current rig is easy -- I put a couple cylinders in the truck bed. However, when I go for a motorhome, and most of them have a fairly small tank, it would be nice to have a cylinder or two for supplemental reserves via an Extend-A-Stay kit.
This is definitely going to get filed under the "bad idea" section, just because a good number of intelligent people confirmed that this isn't exactly the brightest idea to be mentioned on here.
Looks like my best bet would be to see about a small trailer, carry the propane on the nose section. That way, an impact has to go through a lot more before it affects the cylinders.
I am looking to buy a hitch mounted cargo rack with high sides, then bolt (using Loctite Red) onto it a propane rack, and a padlock for the handle, so it doesn't work loose. This would be useful for storing an extra pair of 20 pound propane cylinders on the back of a trailer, or a motorhome.
The bottles will be well anchored, but my biggest worry about rear-enders. Would I be going too far into Ford Pinto territory with this setup, especially behind a motorhome?
Edited -- bad idea, confirmed... won't happen.
When I was looking at truck campers, there appears to be a few modern fridge models which, if they don't have battery, will still cool using propane, but just won't have manual thermostat function, nor will they be able to automatically ignite or put out the pilot light. Not sure which they are, though.
Another idea is to get a Dometic "ice chest" fridge. Not a "thermal electric" cooler -- those are worthless. Buy a true refrigerator with a Danfoss compressor. This can be run off the cig lighter/power port on a vehicle, but it can around three amp/hours so it would be wise to run the vehicle at least daily to counteract this draw. However, this will keep one's stuff cold. Another idea is to set it to 0 degrees F, and use it as a freezer to freeze hard sided gel freezer packs, then rotate those out with coolers. That will help provide more cubic feet for cooling, but will demand more amperage.
I know the OP doesn't want a generator, but I would seriously consider -some- model, even if it is the el cheapo $100 ET-800 knock-off from Harbor Freight. $200 gets you a four stroke Champion 1500 watt model that is relatively easily maintained by oil changes and can be turned off at the petcock so fresh gas can be kept in the engine, while the carb bowl remain dry (to prevent varnish buildup.) The advantage is that it takes a lot less gas to run a small generator than it is to keep a vehicle's engine running, and making fuel go longer is key in a disaster.
You could run jumper cables from your vehicle as well, perhaps even attach an inverter to it for some 120 volt usage. However there is one caveat to this:
I may sound like a doomsayer, but from my experience, come a disaster scenario, stores will be completely cleaned out. There will be no water, gasoline, propane, or other items available. Even if there is a chance of a hurricane going in an area, there will be a run on all stores. By the time there is news of an evacuation, it will be way too late. Stuff will be gone days beforehand.
Generator? If you find one, it will likely be the most expensive models sold, but most likely there won't be anything around.
Gas and diesel? Same thing. Pumps will be empty, and if not, be turned off because the shop owners have locked down everything, and gotten out.
If a hurricane is bearing down, one pretty much either has what they need already stashed well before the weatherman predicts the path coming in, or they are going to be joining the other refugees packed to the rafters in the high school gymnasiums.
Trick is to do a little bit of planning. I personally keep a few 5 gallon gas cans, each with Star-Tron fuel preservative, and rotate those out every 3-6 weeks. I also keep 2-3 extra 20 pound propane bottles as well. In my TT, I tend to keep the FW tank full, as well as keep a few gallon jugs of drinking water.
Food-wise, I keep a 72 hour MRE kit in my TT, as well as some other long shelf life items. The goal is to be able to keep going comfortably for about 3-7 days. That should be rotated out every so often as well.
I have not read about many propane tanks being replaced.
Other than getting the hoses out of the way, there can be the issue with the tank mounts being rusty as well, so it may take some prep/fab work to make sure a new tank can be installed without existing rust being an issue down the line.
Earlier today, I saw this article in passing which had a good guide to wrapping a manifold so the heat stays there, and doesn't wind up in the vehicle.
Another idea is to use HushMat/DynaMat/FatMat (whatever is either the thermal or both thermal/noise... just the noise without thermal will melt) insulation on the floorboards. This is something that I definitely plan to do around the doghouse area.
Worth every penny. Pine cones need to fall on the ground, not get wedged in your slide's mechanism. Plus, it is one additional barrier against water intrusion.
I miss the Solera slide boot/sleeve as an option as well. Even when the slide came in, the water stayed on the outside. However, that company got bought up by LCI, and it looks like that product was discontinued.
On an extreme, I'd consider having the brake shoes replaced. It is $100 or so plus labor, but the most important thing isn't going to be how you climb the hill, it is how you are going to be stopping.
Another item that might come to mind is the transmission cooler. Using this post as a reference, I'd consider replacing the transmission cooler with an aftermarket cooler which has a lot more area. Transmissions function up to a certain temperature... then when they start hitting an inflection point (180-200 degrees), they cook quickly. This is especially important if towing.
Of course, with a newer model of class "C" with an OBD II port, having a Scangauge is good for temperature monitoring.
I have seen tarps chew up rigs after a while, especially when they tear and start billowing. Here in central Texas, between the UV light in the summer and buzzsaw winds in the winter, tarps do not last long. The blue tarps turn to powder in the summer, rip apart, then flay the rig alive come January to April.
The best improvised solution, if at all possible, is what ronfisherman described -- get some schedule 80 1.5" PVC pipe, some clear solvent cement (no need for the purple stuff, since this is about aesthetics, not being water tight), and go from there. The one thing I might add to that would be to have some form of fan (even if it is just a cheapie) to blow air over the top just to keep mildew from forming in a humid climate.
Of course, the absolute best solution is a carport, because if build solidly enough, one can toss solar panels on it, which can always come in handy (or maybe I am just a fan of using any south facing horizontal surface for something productive.)
There are three engines to choose from with US Sprinters:
OM602 -- 5 cylinder engine.
OM642 -- 3.0 V6
OM651 -- 2.1 four cylinder engine.
The OM642 is a smooth engine. The five-cylinder model is noticably rougher, but it can handle a higher percentage of biodiesel. The four-banger has had some good results, but it is more designed for short stops in a city as opposed to going up and down hills and long distance travel.
I have not seen a properly maintained Onan wear out.
On the other hand, I've seen many 10+ year old motorhomes with 5 hours on the clock, which almost certainly means a carb replacement, not to mention that the oil in the genset is likely sludge, and the windings are likely corroded and worthless.
If I had a choice between a model with thousands of hours on the generator (and the owner has done basic Onan upkeep like oil/air filters), I'll take that any day over a genset that has not been run since the PDI when the rig was new.
In LA, I'd say 20 feet is as long as you can go, and there are no "C"s that length, except for a Majestic 19 footer, which has no bed except for the cabover and dinette.
Closest you can go is either a van or a truck camper.
There are ways to mitigate doghouse issues. Winnebago has a trimline drink holder:
More info here.
It won't get rid of the doghouse, but it might just make it less of an issue.
With so many people tossing their absorption fridges for compressor models, I wonder if it might be good for creating a guide of replacement compressor fridges that can most accurately fit into the aperture left behind when the compressor fridge is removed.
This way, someone who has upgraded their solar panels and has a beefy battery bank wouldn't need to have a LP gas fridge, but could pull their existing model of fridge and replace it with something that fits almost exactly in that space.
I can give an anecdotal account. My F-150 is the last year of the 5.4 V-8. The vehicle is about 7000, and can move a 7000 pound trailer slowly, but surely. If that relatively little engine can move that much stuff up and down hills, it can move a 9000-10,000 pound coach decently.
Of course, the V-10 is a lot better, but the V-8 is not too bad.
As for the V-6 with the Sprinter, it isn't bad either.
It sucks either way. More people out there, the more clods doing stupid stuff causing parks to get shut down or new rules made. However, when gas is high and the economy is in the black tank, parks are the first thing to get defunded.