4 Best Undermount Propane Tanks for Van Life

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If you don’t have a diesel heater or a robust battery bank for electric stovetops, a reliable source of propane is essential for cooking and heating while traveling in a van. However, portable propane tanks can become a major expense and source of waste. An undermount propane tank is a popular choice among van lifers because it maximizes interior space and helps your van function more like a self-contained RV. Here is everything you need to know about choosing the best tank for your van.

Can You Mount a Propane Tank Under a Van?

An undermount propane tank is a great option for a van conversion as long as the van has enough clearance and weight capacity to support it. You can fill up your propane at most major truck stops and gas stations. Most horizontal RV propane tanks include mounting brackets that can be attached to the frame of the van, often behind the tire axle. Some tanks include mounting brackets, while some DIYers custom fabricate brackets with angle iron attached to the van cross irons with rivnuts. Ground clearance, hoses, fill gauges, and safety inspections are crucial. Consult a professional RV technician if you are unsure about using propane in your van conversion.

How to Choose an Undermount Propane Tank

Propane has been safely used in the RV industry for decades, however its flammability is certainly a concern for van lifers, particularly if you are doing a DIY build. Before choosing an undermount propane tank, consider:

  • Horizontal vs. Vertical: Horizontal tanks are the only option for undermounting because they have mounting brackets in a location where they can securely attach to the van. Vertical tanks should only be mounted on the rear bumper with a cage or towable cargo rack.
  • Size: Most vans use a 20-50 lb (4.6 to 12.2 gallons) undermount propane tank, but larger are available. If you plan to use propane for cooking, heating, and hot water, a 50 lb tank is best.
  • Clearance: The tank needs to be mounted high enough off the ground to avoid damage while you’re driving, particularly on rough backroads. A 7” clearance from your tank to the ground is ideal, but be sure you can still fill your tank if you tuck it up inside the cross members of the van. If your van is fairly low, you may opt for a rear-mounted tank.
  • Material: The best propane tanks are made of aluminum or high-grade welded steel with a powder coating for exterior protection.
  • Safety: Ensure the tank includes a fill valve, a relief valve, and a level gauge. Regularly inspect your tank and hoses to ensure there is no physical damage or leaks. Always install a carbon monoxide alarm inside the van and use a vent fan while cooking.
Propane is essential for a comprehensive cooking and heating setup

You will also need to consider which type of propane tank works best for your van. The two main types of propane tanks are:

  • ASME Tanks: These permanently mounted tanks are designed with a thicker, heavier metal certified by the American Society of Mechanical Engineers (ASME) for use in motorhomes. 
  • DOT Cylinders: You often see these cylindrical tanks vertically secured on the back bumper of a camper. They are removable and refillable, but cannot be safely mounted under the van. The Department of Transportation (DOT) regulates these propane tanks, from 1 lb disposable sizes to the 50 lb cylinders you often see at hardware stores.

Most motorhomes have an undermount ASME tank, while tow-behinds have the DOT cylinders you often see mounted on the back. An ASME tank is typically the best option for van life if you want to keep your fuel source outside of the vehicle.

Top 4 Best Undermount Propane Tanks

Top Pick: Flame King 12.2 Gal ASME RV Trailer Propane Cylinder Tank

An industry standard for RVs and campervans, the Flame King is designed to mount underneath your vehicle. It is robustly and safely designed with a compact 12.3” diameter, 28” length, and 15.5” inch height, including the bracket and collar. Flame King is one of the most well-respected manufacturers in the industry and includes all necessary safety certifications. 


  • Mounting brackets are welded into the tank
  • 12.2-gallon capacity
  • Fill valve, relief valve, and level gauge installed and included
  • High-grade welded steel construction
  • Powder coated for longevity


  • High price point
  • Tall height clearance (some van lifers modify the bracket height like in this video)

Best for Low Clearance: Manchester Tank LP Tank with Regulator for Bus/Vanagon

If you don’t have as much clearance space under your van, this tank is just 12.5” tall and elongated for a more compact fit. Originally designed for Volkswagen Westfalia vans, it is no surprise that this specialized undermount propane tank can fit in tight spaces. Manchester Tank is a federally compliant manufacturer providing quality modern designs, fittings, and safety features. This tank includes a skid plate, 3.3 gallon capacity, and an internal auto-stop valve.


  • More compact and elongated for low-clearance vans
  • 3.3-gallon capacity
  • Internal valves included
  • Exterior regulator with plastic covers
  • Easy to fill and access


  • High price point
  • May require adapter brackets

Budget Pick: Flame King 20 lb Horizontal Propane Tank

This low-profile budget tank is used for RVs, campers, and barbecues. The mounting brackets aren’t as ideal for a van, but you can certainly modify the cylinder to fit under a mid-to-high clearance conversion van. This Flame King includes an overflow protection device valve, a formed handle, and two gauges (one for horizontal mounting and one for vertical mounting).


  • Affordable
  • Compact (12” x 17” x 13.5”)
  • High-grade steel welded (rust-free!) and powder-coated
  • Two gauges for versatile mount readings
  • DOT approved 


  • Small capacity (4.6 gal) 

Largest Capacity: Manchester Tank 16.36 Gal 14” x 40” ASME Tank

If you need a lot of propane for an extensive amount of appliances, this RV undermount tank holds 16.36 gallons of propane.


  • Large amount of propane for heating, cooking, hot water, and BBQing
  • Made in the USA by a reputable manufacturer 
  • Designed specifically for motorhomes


  • High price point
  • No dial chamber
  • Large size (36.5” x 15.3” x 15.3”)
  • Heavy (88 lbs) and may compromise fuel mileage

Key Takeaways: Prioritize Clearance, Safety, and Capacity for an Undermount Propane Tank on a Van

The RV industry saves the day for van converters who no longer want to rely on portable propane canisters! Undermount tanks are widely available and compatible with many vehicles as long as you properly measure the clearance, securely install the mounting brackets, and follow all safety measures for running hosing into the van. When in doubt, hire a professional to install your propane system. A mistake is not worth the risk of an explosion!

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Logan Hailey is a writer, natural wellness educator, and full-time van lifer. A nomad at heart, she has lived on the road for 5 years and counting, first in a DIY skoolie and now in her self-converted Sprinter van. She is passionate about living in harmony with nature and creating off-grid van vessels to enjoy the beauty of wild places. Keep up with her adventures on Instagram (@naturallylogan), TikTok, and YouTube.

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