Someday, overlanding will be an electric-powered activity, with long-range electric engines in most rigs. But for now, most explorers are petrol powered and need to invest in overland gas cans to store extra fuel.
One of the benefits of an internal combustion engine is that you can extend the range of your vehicle simply by bringing additional fuel. In this guide, we go over some of the basics for fuel planning and storage on overland trips. We’ll also give you some tips on buying fuel cans and offer specific recommendations.
- Overland and Off-Road Fuel Planning
- Best Gas Cans for Overlanding and Off-Roading
- Overland Fuel Storage Best Practices
Overland and Off-Road Fuel Planning
First, we’ll dispel a myth. You don’t always need extra fuel when going off-road. In fact, I carry extra fuel only on a small percentage of my backcountry adventures.
I often go on day trips to hit local trails and use less than half a tank of gas. In such a case, where you are just a few miles away from a paved road and have plenty of range with your stock gas tank, carrying extra fuel is just carrying unnecessary weight.
That said, there are plenty of good reasons to carry extra fuel. If there is any chance I could run out of gas on the trail, I bring a gas can as a precaution. Some off-roaders like to bring extra fuel even though they don’t need it, just for peace of mind. And some trips are long enough and remote enough that bringing additional fuel to extend your range is required.
How much extra gas should I carry?
The short answer is that you should bring enough for your trip and some extra as a hedge against unforeseen circumstances.
Really, when considering how much fuel to bring, there are a lot of different factors to consider.
How far will you travel between gas stations?
This is the most fundamental calculation. You’ll need at least as much gas as it takes you to get from gas station to gas station without running out of fuel.
You can calculate this basic number by dividing the distance between fueling stops by the gas mileage of your vehicle. So it looks like this:
Distance between gas stations/gas mileage = fuel needed
As an example, let’s say I will need to travel 100 miles between fuel sources in my Jeep Wrangler which gets 15 miles to the gallon. The equation looks like this:
100 miles ÷ 15 miles/gallon = 6.7 gallons
So I’ll need a minimum of 6.7 gallons of gas in my fuel tank to make it from gas station to gas station. Somewhere in that stretch, I’ll travel off-road, but what really matters is that gas station to gas station distance.
How much buffer are you comfortable with?
Personally, I get nervous when I’m on a trail and the needle on my gas gauge tells me I’ve got less than a quarter tank. Ideally, I like to have at least a quarter tank left when I get back to the gas station to refuel after a trail ride.
Planning for that gives me some wiggle room to deviate a bit from my planned route, and gives me a decent margin for error – for instance, in case a route is impassable and we need to reroute.
What is your vehicle’s maximum range?
The size of your gas tank and your gas mileage will determine the maximum range of your vehicle. The way to calculate this range is simply to multiply your gas tank volume by your gas mileage. The equation looks like this:
Gas tank volume x gas mileage = vehicle maximum range
For my gas-hungry Jeep Wrangler with its 20-gallon tank, the equation looks like this:
20 gallons × 15 miles/gallon = 300 miles
One thing to note is that this uses my average gas mileage of 20 gallons. If I was traveling slowly on rough terrain, my gas mileage would be lower which is something I’d need to account for.
Putting it all together, if I was to go on a trip that required 200 miles of travel between refueling stations, I would use a little over 13 gallons of gas. That would leave me with around a third of a tank of gas when I arrive at the refueling station. I’d feel comfortable taking the trip without bringing extra fuel if the route was fairly predictable.
If I was exceeding my maximum range, I’d do this calculation to figure out how much extra fuel I can carry:
Extra fuel needed = (Trip distance – Maximum range) ÷ Vehicle gas mileage
So for my Jeep, on a 400-mile trip the calculation would look like this:
(400-mile trip – 300-mile maximum range) ÷ 15 miles/gallon gas mileage = 6.7 gallons extra fuel
To account for a quarter tank extra in case of unforeseen circumstances – an unplanned detour, for instance – I’d add 5 gallons to the extra fuel need (see below for more on assessing the risk of a detour).
How risky is your route?
Even if your planning shows that on paper you should have plenty of fuel if your route is particularly precarious it is a good idea to bring extra fuel. For instance, if inclement weather like rain or snow might require you to take a long detour, bringing an extra can of gas is wise.
Another type of risk is how dangerous it could be if you were to run out of fuel. If you are in an extremely remote area, or a region with extreme temperatures such as hot deserts or freezing tundra, running out of fuel could be disastrous. Better safe than sorry.
Lastly, longer routes present greater chances of long detours. Needing to reroute on a day out on a short local off-road route may require just a few extra miles of driving. In contrast, a hundred-mile detour in the Alaskan backcountry will suck up quite a bit of gas. Again, better safe than sorry.
What is your vehicle’s payload?
Every vehicle has a maximum payload, which we explain in depth in a separate article. So the amount of fuel you bring needs to be accounted for in your overall payload planning. For reference, one gallon of gas weighs around 6 pounds (in metric units, one liter of gas weighs 0.75 kilograms).
Because gas weighs so much, it’s best to only bring as much extra fuel as is necessary to cover the required distances and have a buffer in case of surprises.
Best Gas Cans for Overlanding and Off-Roading
To carry additional fuel on overlanding and off-road trips, you’ll need gas cans and some way of carrying them. Below, we’ll list a few types of common fuel containers and mounting systems and highlight some good options for each.
Gas Jerry Cans
First developed for the military during World War 2, jerry cans have long been the fuel cans of choice for overland expeditions and off-road enthusiasts. Jerry Cans have several benefits.
They are just the right size for a single person to pick them up comfortably, which makes them relatively easy to lug around (that said, a full jerry can is pretty heavy, which can be a downside if you have a bad back or other physical limitations). Some jerry cans are available in half sizes if weight or space is a concern.
Another advantage is that If you buy a jerry can that is to NATO specs, they come in a standard size. This means you can easily find mountain brackets to hold them and may even be able to swap them between racks on different vehicles.
Rotopax and FuelpaX
One of the criticisms people have of traditional jerry cans is their large size. They can be heavy when full and take up a lot of space, even if you don’t need a full can for your outing. The company Rotopax addressed this by developing a more modular fuel can system for overlanding and off-roading.
The Rotopax system uses smaller plastic fuel designed to stack onto a specialized mounting bracket. This allows you to easily flex how much fuel you bring on a trip – adding additional cans as you need more fuel. Because the individual cans are smaller and hence lighter, they are also easier to carry.
The primary downside of these modular systems is their high cost. As I’m writing this, I can buy a 5.3-gallon jerry can from Wavian, a quality brand name manufacturer, for about $90. In contrast, a 2-gallon Rotopax can cost around $85. So you are looking at nearly twice the cost for the same volume (actually a little less volume).
FuelpaX is another line of gas cans made by the Rotopax company and seems to be their answer to the high cost of the Rotopax cans. The Fuelpax cans are blow-molded and have thinner walls, which presumably makes them a bit less durable than the Rotopax cans (which are rotational molded).
It’s a bit difficult to compare the costs of the mountain brackets, as there are many different versions for both types of cans, but I’m going to go out on a limb and say they are roughly similar.
Another issue that I’ve run into with Rotopax is that they need to be vented when you change elevations. I was driving up a mountain one day and my Rotopax can started spewing gas out of the gasket between the lid and the can due to the pressure change.
Rotopax says you need to vent the cans when you change elevation, but that can be a pain. I’ve heard other people tighten the lids quite tightly to prevent leaking. I haven’t had this same issue with jerry cans, possibly because they are larger and I don’t fill them as much so there’s more room for the air to expand. Just a guess, no science behind that.
Large Fuel Storage Tanks
If you are planning a long expedition such as traveling one of the transcontinental overland routes, refueling stops at times may be few and far between. Routes like the Pan American Overland or the Cairo to Capetown route across Africa will require you to carry larger amounts of fuel to cross areas where none is otherwise available.
For most people, carrying multiple smaller jerry cans or modular systems such as Rotopax make the most sense, but a large tank may have advantages in terms of weight to fuel volume and overall cost of the tank.
For some models of vehicles, it’s possible to replace your existing gas tank with a larger one or to add a model-specific auxiliary gas tank. Companies like Long Range America and Titan Fuel Tanks make a variety of auxiliary tanks. Alternatively, there are vehicle agnostic tanks that are available that can be carried in a truck bed or trailer.
Overland Fuel Storage Best Practices
Once you’ve figured out how much fuel you will need and how you will transport it, there are some other best practices to keep in mind when carrying fuel into the backcountry.
Over time, gasoline stored in containers will degrade due to oxidation and evaporation, which can make it burn less efficiently in your engine. If you are planning to store gasoline for more than three months, it’s a good idea to add a fuel stabilizer to prevent degradation. A good option is STA-BIL Storage Fuel Stabilizer, which will prevent gas degradation for up to two years.
Where to store a gas can on a vehicle? This can be tricky, given that you may have spare tires, Hi-Lift jacks, and other gear to carry on your rig.
It’s tempting to put cans on the roof, and sometimes unavoidable. But doing so raises the vehicle’s center of gravity making it less stable and the cans will slosh around more.
The ideal location to store fuel cans when overlanding and off-roading is near the rear bumper. It may go without saying, but avoid storing fuel cans inside the vehicle to avoid fumes and fire danger.