Quick Answer: What is a jerry can? It is a rugged, portable container for fuel or water, usually holding about 5 gallons (20 liters). It has three handles for easy lifting and a sealed spout for pouring. Overlanders use it to extend range, carry water, and refuel generators.
Picture a dusty fuel stop 120 miles behind you and a trailhead 90 miles ahead. That is the moment a spare can earns its spot on the rack. Below, I answer the questions new RV and overland travelers ask me most, one straight answer at a time.
Please note: This article is for general educational and planning guidance. It does not promise specific results and works alongside advice from qualified professionals. Some tasks, such as propane work, electrical installs, and heavy-duty mounting, are best handled by a trained technician. Please check your vehicle’s owner’s manual, weight-rating labels, and current local and campground rules.
Q: So, What Is a Jerry Can, Really?
A jerry can is a tough, portable container built to carry fuel or water. The classic shape is a flat-sided rectangle with three handles across the top, a screw or cam-lock closure, and pressed ribs that add strength. Most hold about 5 gallons (20 liters), a size one adult can lift without too much strain.
On a long weekend in a Class C, I mostly use mine to top off a portable generator. On a backcountry trip in a Tacoma, the same style of can adds range between pumps. One container, many jobs.
Myth vs reality: Many people think any red plastic gas can counts. In reality, the true design has flat sides that pack tightly, three handles for passing it along, and a gasket-sealed lid meant to resist leaks on washboard roads. Plenty of look-alikes exist, so check the build.
Takeaway: Think of it as a sturdy, stackable, sealed container made for rough travel.
Q: Where Did the Design Come From?
The design was developed in Germany in the 1930s and widely copied by Allied forces during World War II. It lasted because it works. Flat sides pack tight on a vehicle, and the handles let people pass cans along a line.
Three Handles
One handle lets you carry the can alone. The other two let you hand it up to a friend on the roof or pass it down a line. Gloves fit easily, which helps in cold weather.
Flat, Ribbed Sides
Flat faces let cans sit side by side without wasted space. The pressed ribs stiffen the walls so the can holds its shape when full.
Sealed Lid and Gasket
A rubber gasket sits under the closure to help block drips and fumes. It is the part that wears first, so inspect it often.
Spout and Vent
A flexible or rigid spout directs the pour. A small vent lets air in so fuel flows smoothly instead of glugging and splashing.
Takeaway: Every feature solves a real trail problem: carrying, packing, sealing, and pouring.
Q: Steel, Plastic, or Water Can: Which Should I Choose?
Each material suits a different trip. Steel feels bombproof, while plastic is lighter and often cheaper. Water needs its own dedicated can.
Jerry Can Types Compared
A common US habit is red for gasoline, yellow for diesel, and blue for kerosene, with a separate blue or white can for water. It is a convention, not a rule everywhere, so label every can with a permanent marker.
Decision rule: Choose steel if your rack takes hard knocks. Choose plastic if you want light weight and low cost. Pick a dedicated water can if drinking water is the goal.
Q: Will It Fit My Rig and Trip Style?
Almost every rig can use one, but where it rides changes with the vehicle. Fuel containers do not belong in living areas, so plan an outside spot first. Many owners find that one or two cans cover most trips.
Rig Fit Guide
Here is a quick look at how many cans different trip styles usually call for. Treat it as a starting point, not a rule.
0-1 fuel can
1 fuel, 1-2 water
1-2 fuel, 1 water
Plan by range math
The more remote the trip, the more the can count depends on your fuel range and local fuel stops. Add cans only as weight and mounting space allow.
Q: How Do I Fill, Carry, and Pour Safely?
Good habits matter more than expensive cans. First, a look at the path from shopping to your first trip.
Match size and material to your rig
Mark contents and fill date
Outdoors, on the ground
Upright, strapped, outside the cabin
Check the gasket and mounts each trip
The flow is simple, and each step catches a different problem before it reaches the road. Skipping the label step is the most common slip.
Safety Note: Fuel vapors are flammable and can travel along the ground to ignition sources. Keep cans out of the cabin, away from generators while running, and never store them in a living area. For generator and fuel hazards, see the consumer guidance at the US Consumer Product Safety Commission.
Still deciding whether you need a can at all? Use this simple path.
If you answered “no” to the safe-spot question, pause and rethink the plan before buying anything.
Q: How Heavy Is It, and Where Should It Ride?
Fuel is heavier than most people expect. Gasoline weighs about 6 pounds per gallon, diesel about 7, and water about 8.3. A full 5-gallon can is roughly 30, 35, or 42 pounds, plus the can itself. An empty steel can often weighs around 10 pounds.
Heads-Up: Weight adds up fast on a roof rack. Check your vehicle’s roof load rating, your payload, and your trailer’s tongue weight before adding cans. When in doubt, mount low and close to the vehicle’s center.
Best Practice vs Less-Effective Habits
When choosing a can, some features deserve more attention than others. This bar chart shows a general practical guide, not test data.
Leaks and loose mounting cause the most trouble on the road, so put your budget and attention there first.
Q: What Goes Wrong, and How Do I Catch It Early?
Most problems show up as smells, swelling, or slow pours. A quick look before each trip catches them.
Common Issue vs Likely Cause
Tip: Write the fill date on a strip of tape. A can with a date tells you at a glance whether the fuel is fresh or due for use.
Before every trip, run through this short checklist.
Two minutes of checking beats a fuel-soaked rack in the middle of nowhere. Make it part of your regular pre-trip walk-around.
Q: What Mistakes Do New Owners Make?
Common Mistake vs Better Choice
Note: Gas cans sold in the US often come with newer spill-resistant spouts. They can feel slow at first, but many owners find they pour cleanly after a little practice. Follow the instructions that come with your can.
What Seasoned Travelers Notice First
- Rack rub marks. A bright patch of worn paint tells you a can is moving.
- Fuel odor after a bumpy day. Even a faint smell is worth tracing to the source.
- Trail cleanup. Practice Leave No Trace and carry spill pads. Never dump unused fuel on the ground.
- Fire restrictions. Check US Forest Service alerts before using stoves or generators.
Q: Any Gear Worth a Look?
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Steel NATO-Style Jerry Can
A classic steel build may suit rough roads and long trips. Compare gasket quality, closure style, and capacity before choosing.
Plastic 5-Gallon Fuel Can
A lighter option that can help keep weight down for weekend trips and generator refills. Look for a clear fuel rating and a secure closure.
Jerry Can Mount or Holder
A purpose-built mount may help keep a can upright and secure. Match it to your rack or bumper rating, and consider professional installation for structural mounting.
When to contact a professional: See a qualified technician if you smell fuel with nothing visibly wrong, plan to bolt a mount to a roof or bumper, or want to add auxiliary fuel storage to your vehicle. A professional can also check the rack’s load rating and the legal limits where you travel.
Frequently Asked Questions
What is a jerry can used for?
It carries fuel or water in a portable, easy-to-handle container. Overlanders use it for extra driving range, RV travelers use it for generator fuel, and campers use water versions for drinking and cleanup.
How many gallons does a jerry can hold?
Most hold about 5 gallons (20 liters), though some run slightly larger or smaller. Always leave a little air space at the top so liquid can expand.
Can I store fuel inside my RV or camper van?
It is best not to. Fuel vapors are flammable, and living areas often have flames, pilot lights, or electrical sparks. Store cans outside, secured and ventilated, and follow your rig’s manual.
Is steel or plastic better?
Neither wins every time. Steel tends to handle rough racks well but weighs more. Plastic is lighter and often costs less, but sun and age can wear it down.
Can I use a jerry can for drinking water?
Only if it is made and marked for potable water. Never reuse a can that has held fuel, and keep fuel and water cans clearly labeled and separate.
How long can fuel sit in a jerry can?
It depends on the fuel, temperature, and whether a stabilizer was added. Gasoline can go stale within months, so label the fill date, rotate your stock, and follow the fuel maker’s guidance.
Final Thoughts
So, what is a jerry can? It is a simple tool that quietly makes longer trips possible: a sturdy, sealed, easy-to-carry container for fuel or water. Pick a type that fits your rig, label it, mount it outside living space, and inspect it before every trip. Check your owner’s manual, weight ratings, and local rules first, and ask a qualified technician for help with mounting, fuel-system questions, or anything that feels beyond a safe DIY job.
