RotoPax Question

[Dano]

Pretty much a novice in the off-road realm but made the transition and am trying to learn as much as I can hoping to optimize my introduction.

Not sure what future adventures may hold but there’s a good chance I’ll be bringing some extra fuel along for the journey. I’ll be mounting RotoPax container on my roof rack (they’ll be lying horizontal on their flat side). Been reading a bit about heating and thermal expansion and hoped to avoid problems. Not sure if this is a real vs theoretical issue. Would it help to include a reflective or white exterior top cover to reduce the heating?

At the risk of getting some lol comments about how I could just use my tinfoil hat for this purpose, was curious if a reflective surface is a good or bad idea.

Thanks!

 

[EOD Guy]

I, for one, would never mount a container full of flammable liquid on the roof of any vehicle, where if that container should leak and subsequently catch the vehicle on fire, the said fire would prevent me from exiting the burning vehicle.................

 

[RideWithYanu]

Hopefully you don’t mind I’m not answering your actual question, but since you’re new to this consider how the ride will be impacted by adding weight to the top of your vehicle. You probably won’t notice a single 5 gallon too much, but generally you want to keep your center of gravity as low as possible.

My eventual plan for carrying additional fuel will be mounting to the rear bumper.

 

[Mtn40]

I agree with the others, though I've considered roof mounting my Wavian fuel cans if needed. Bumper would be better, but I see way more rear-end collisions than rollovers. Rollovers are way worse. ...that's another rabbit hole.

As for the heat, a reflective cover would reduce the heat and therefore pressure in the container. It's not a bad idea, but maybe not necessary.
There's a lot of good reading on the Rotopax FAQ page. They recommend venting occasionally and keeping the container either full or empty to minimize fuel vapor inside. Good idea for any aux fuel container.
RotopaX | Frequently Asked Questions | RotopaX

 

[rysn]

I would advise against it, personally. I do see a lot of people doing it & even some brands with adverts clearly showing an extended roto on the roof.

You do risk leaking fuel & it obviously will add weight increasing your center of gravity. Keeping it in the boot is also a hard no so, this is the most cost effective way to extend your range. So, do some more research outside of the forums, reach out to Roto, they might be able to provide more insight. Edit: Someone posted a FAQ for you.

If you end up enjoying off-roading & end up not mounting on the roof, I would suggest investing in a few upgrades that can help manage this.

A new rack that can support rear window saddle panels, check out Prinsu. If you have a sunroof, Toyota makes a 2/3 rack similar to the Prinsu rack. In my opinion, the only other viable option that keeps off-roading top-of-mind is a new rear bump with a swing.

You can always pick up a hitch mounted carrying system, but I don't recommend that option.

Since you are new to off-roading hitch mounted anything increases the likelihood you will get hung up on something. Try to avoid anything being left in your rear hitch as much as possible. This is why I do not recommend getting a carrying system for the hitch.

In the future Long Range America will be releasing their 16g Saddle Tank & 24g AUX Reserve Tank in The States. They should go for $2400 - $3000 based on current inventory.

 

[45.BWhite]

I've got a couple of Rotopax mounted on my roof and wanted to share my experience.

I actually had one of my Rotopax burst and start leaking on my recent southwest trip. It was a full tank. I drove from Vegas (101 degrees) to Zion (107 degrees). The tank was vented in Vegas while parked in the shade, but I think between the elevation change and being parked in direct sun, it was just too much pressure.

As for the weight on top of the vehicle, I run two 3-gallon tanks plus a Waterport, and honestly, I haven't noticed any change in feeling or tippiness. The Land Cruiser handles the weight really well, which is definitely a good thing. The battery mounted lower in the back really helps lower center of gravity.

 

[EOD Guy]

A lot of valid points above. (I don't think top heavy would be a factor) If you don't plan on doing any rock crawling or hard core trails, I think a receiver hitch mount would do you just fine. A very simplistic "L" shaped mount would be more than strong enough to support a couple of rotopacs and if you really needed to, you could remove the mount to get past a tough spot, then reattach it.

(edit) any welding shop should be able to fab something like this in 30 mins.

 

[Dano]

Thanks to all for the reply’s - some of which got my sphincter clamped down to an 8 outa 10! As was stated, I too have seen plenty of pictures of even 4gal tanks adorning roof racks like big sunbathing lobsters; I figured this was routine.

Take home for me is that the side window panels are likely the best way to go (though a bit pricey). Appreciate the good advice.

 

[45.BWhite]

Regarding side mount rack options, I recently spoke with the owner of Prinsu. He mentioned they're looking into some designs that would work with existing factory racks.

My main concern was definitely wind noise with side-mounted items. However, he told me that with their design, the mounts would be far enough back that any wind noise generated wouldn't be close enough to the driver to be easily audible.

 

[Dano]

$900 for a couple side panels seems a bit steep but it will lower my center of gravity, minimize leak potential, and perhaps prevent my becoming a human candle. Interesting point about noise and associated drag tho. Self fulfilling prophecy of sorts: will further reduce my mpg requiring me to potentially carry more gas.
The suggested hitch mount solution would offer similar or better benefits but I don’t yet trust my driving skills to take this on.

 

[EOD Guy]

$900 for a couple side panels seems a bit steep but it will lower my center of gravity, minimize leak potential, and perhaps prevent my becoming a human candle. Interesting point about noise and associated drag tho. Self fulfilling prophecy of sorts: will further reduce my mpg requiring me to potentially carry more gas.
The suggested hitch mount solution would offer similar or better benefits but I don’t yet trust my driving skills to take this on.

You're only giving up an inch or two of horizontal clearance and that shouldn't make a big difference unless you get into a serious departure angle situation (like a bowl).

 

[what_have_they_done]

Are you in USA? Only time I get range anxiety in USA when I'm in mountains moving back and forth between spots and not really leaving area, otherwise there is gas every 60 miles max. Just make sure you really need that extra fuel, my rotopaxes filled with water lol.

 

[Jeff Cooper]

While I am not necessarily a fan of mounting fuel on top, I did just that prior to a 3 week, 3,000 mile trip from southern Arizona to northern Wyoming last month. Our elevation ranged from 3,600' up to over 10,000' coupled with temperatures ranging anywhere from the low 70's to as high as 110. Because of that, I only put 1.8 gallons into each (2 gallon) containers. We had zero issues the entire trip

 

[RideWithYanu]

While I am not necessarily a fan of mounting fuel on top, I did just that prior to a 3 week, 3,000 mile trip from southern Arizona to northern Wyoming last month. Our elevation ranged from 3,600' up to over 10,000' coupled with temperatures ranging anywhere from the low 70's to as high as 110. Because of that, I only put 1.8 gallons into each (2 gallon) containers. We had zero issues the entire tripView attachment 44332View attachment 44332

As with just about any liquid-storage container in existence, refraining from filling to max capacity is very prudent!

 

[Dano]

I thought I had read that it was best to fill the Rotopax container FULL with gas to minimize vapor layer volatility and expansion (though still need to vent it periodically). However, less than full filling seems to make sense!

I’m in the USA and unfortunately appear to have a lead foot. I’m getting 17.4 mpg city driving, and figured things would be worse when exploring. You’re still probably correct that a gas station isn’t far away, but I am a little bit paranoid re low fuel situation when in the sticks.

 

[kruising]

Victory 4x4 makes an LC250 side panel for just over $200 that fits on the factory rack with the only mod being opening up the top angle a little bit. A machine shop did the bend for me for a $20 donation to their donut fund.

 

[45.BWhite]

Victory 4x4 makes an LC250 side panel for just over $200 that fits on the factory rack with the only mod being opening up the top angle a little bit. A machine shop did the bend for me for a $20 donation to their donut fund.

View attachment 44756

That metals is a little thin. How is the stability

 

[kruising]

That metals is a little thin. How is the stability

It's quite stable because it's just hanging on the rack. I did add a second suction cup on the window.