Gasoline and diesel heaters from companies like Espar, Webasto, and Planar are designed specifically for heating the cabins of vehicles like campervans, trucks, and global expedition vehicles. Regardless of the fuel type, forced-air heaters will operate in most environments, and some even perform well up to and above 10,000 feet in elevation. Although they cost more upfront, high-quality heaters are a worthwhile investment in the long run if you want reliable heat at the touch of a button.
Given that there are many different models to choose from, we’ve put together this gasoline and diesel heater buyer’s guide. It aims to point out the differences between the most popular heaters currently available so that you can select the best one for your particular needs.
Popular Gasoline & Diesel Heaters for Car Camping and Overland Travel
Espar Airtronic: Diesel or gasoline versions, some models operate up to 10,000+ feet
Webasto Airtop: Diesel or gasoline, some models offer up to 18,000+ BTU output
Planar 2D- and 44D-HA: Affordable, diesel-only, economic fuel-consumption
Why add a heater to your overland rig or campervan?
Have you ever set up camp in sub-freezing temps with snow falling? Without the warmth of a cozy cabin to retreat to, this experience is less than ideal. Your fingers start to hurt, your clothing gets damp, and your motivation to complete even simple tasks quickly deteriorates. Yes, cold weather can make overland travel much less appealing.
That’s why installing a stand-alone heating system in your overland rig or campervan is a great idea. A heated cabin can return your will to preparing food or look over your route for the next day. And in the most extreme instances, having auxiliary heat could even be the difference between comfort and frostbite.
Photo: Matt Swartz
But with so many different vehicle heaters on the market, the important question remains: what type of heater is best for your overland rig? Let’s start by digging into the two main types of forced-air heating systems: diesel and gasoline.
Diesel Forced-air Heaters
Diesel air heaters help maintain a comfortable temperature in your van or truck with high levels of safety and minimal maintenance.
In general, diesel forced-air heaters use a modest amount of fuel: approximately 1-2 gallons for 24 hours of operation, depending on heat output. They can be plumbed into your vehicle’s fuel tank, or if your vehicle runs on gasoline, they can be set up with their own independent fuel tanks.
Photos: Richard Giordano
Diesel air heaters require a 12- or 24-volt electrical source to power their fuel pumps and fans, so you’ll want a dual-battery system if you plan to run them for extended periods of time, like overnight.
Gasoline Forced-air Heaters
Like diesel air heaters, gasoline air heaters help maintain a comfortable temperature inside your vehicle in a safe and convenient system.
Gasoline heaters tend to use a little bit more fuel per/BTU than comparable diesel heaters, but they are still relatively efficient. Gasoline heaters can also be plumbed into your vehicle’s fuel tank, making it very unlikely that you will ever be left without heat in the middle of the night.
Common Questions About Diesel and Gasoline Air Heaters
Which is better, a diesel or gasoline air heater?
The answer to this question is multifaceted. Let’s start by discussing fuel efficiency.
Because diesel is denser than gasoline in terms of its overall mass, it has more energy per volume. Given this fact, diesel air heaters tend to be more fuel-efficient than their gasoline counterparts.
But fuel efficiency isn’t the only factor to consider when deciding whether to choose a diesel or gasoline heater. For instance, if you have a gasoline-powered vehicle but you choose to install a diesel heater for its superior fuel efficiency, you’ll need to fill a separate diesel fuel tank and keep extra diesel on hand in your rig. In this case, choosing a gasoline heater and plumbing it directly into your fuel tank will simplify refueling and effectively provide you with an almost unlimited reservoir of fuel. The simplicity that comes with this integrated system that doesn’t require a separate type of fuel may be more than worth sacrificing a little bit of efficiency.
Maintenance is another consideration in your choice of a diesel or gasoline heater. While I haven’t found any concrete argument proving that one brand or fuel type is better in this regard, there is anecdotal evidence that suggests using both diesel and gasoline heaters at higher elevations results in the need for more frequent maintenance.
I would say that for the majority of travelers, it will be easiest to select a heater that matches the fuel type of your host vehicle.
How Do Diesel Air Heaters and Gasoline Air Heaters Work?
These heaters function the same, except for the fuel that they require. They burn fuel to heat a heat-exchanger, over which air is blown into the cabin of your vehicle. Cabin temperature is adjusted via a thermostat that controles the speed of the internal fan. Some newer heaters feature integrated altitude compensation that automatically adjusts the fuel to air ratio, ensuring complete and proper combustion. Some older heaters may require the addition of high-altitude modules to allow for proper operation, above 5000 feet, for instance.
Do diesel air heaters produce fumes?
Diesel and gasoline air heaters do produce exhaust fumes. However, the fumes are blown outside through an exhaust outlet and never enter the cabin of their host vehicles. Because of this, gasoline and diesel air heaters offer a high level of safety. It is still highly-recommended that you install a carbon monoxide detector inside your vehicle.
Are diesel and gasoline air heaters safe?
Diesel and gasoline heaters are generally considered safe for a variety of reasons:
- They cannot be knocked over accidentally.
- Most modern, high-quality diesel and gasoline air heaters feature built-in safety shut-off mechanisms.
- Because you don’t need to refuel them directly, there is no risk of spilling fuel inside your vehicle.
- The combustion process is isolated from the cabin of your vehicle, so there is little risk of oxygen deprivation or carbon monoxide poisoning.
Where do diesel and gasoline air heaters get fuel from?
Both diesel and gasoline air heaters can be plumbed into your vehicle’s fuel tank, giving them an almost limitless supply of fuel. Alternatively, these types of heaters can be set up with independent fuel tanks, too. For instance, a gasoline vehicle could have a diesel air heater installed with its own tiny diesel fuel tank, like in Ashley and Richard Giordano’s Toyota pickup.
What about propane heaters?
Yes, propane heaters are an option, and some are superior to others.
Catalytic and ceramic blue-flame heaters are widely available and inexpensive, but they have some downsides. They have a hot surface (fire hazard), and they also consume oxygen in the space where they are being used, requiring you to have ventilation, which partially defeats their purpose of heating your enclosed area. Finally, water vapor is a byproduct of the propane combustion process, and this water condenses on the inside of your vehicle walls which can lead to rust and mold.
Left to right: Camco Olympian Wave (catalytic), Mr.Buddy (ceramic blue flame), Propex (forced air), Dickinson Marine (radiant)
The only two propane heaters that we would recommend as alternatives to diesel or gasoline forced-air heaters are from Propex and Dickinson Marine. We’ll cover those two heaters in a future propane heater buyer’s guide.
Choosing the Best Gasoline or Diesel Air Heater
To be clear, the best heater for your vehicle will depend on the square footage that you need to heat. Getting a unit that is too large will consume excess fuel and may produce too much heat. Getting a unit that is too small will consume excess fuel and may not achieve the warmth you need. You’ll want to dig into the details a bit more, but to get you started, here are the diesel and gasoline air heaters that are widely considered to be the best on the market with their corresponding BTU ranges.
Espar Heaters
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- Espar Airtronic D2 12/24V Diesel Heater: 2,100-7,500 BTU
- Espar Airtronic D4 12/24V Diesel Heater: 3,400-13,650 BTU
- Espar Airtronic B4 12/24V Gasoline Heater: 4,436-12,970 BTU
- Airtronic S2-D2L 12V Diesel Heater: 2,898-7,502 BTU
- Airtronic M2-B4L 12V Gasoline Heater: 4,433-12,958 BTU
Webasto Heaters
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- Webasto Air Top 2000 STC Diesel or Gasoline: 3,100 – 7,000/3,070-6,800 BTU
- Webasto Air Top Evo 40 Diesel Heater: 5,100 – 18,800 BTU
- Webasto Air Top Evo 55 Diesel Heater: 5,100-18,800 BTU
- Webasto Air Top Evo 40 Gasoline Heater: 5,800-13,650 BTU
- Webasto Air Top Evo 55 Gasoline Heater: 5,800-18,800 BTU
Planar Heaters
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- Planar 2D-HA Diesel Heater: 2,700-6,850 BTU (Field tested by Richard Giordano)
- Planar 44D-HA Diesel Heater: 3,200-13,600 BTU
But there are so many different model numbers to choose from…
I feel your pain, and I am well aware of this. The seemingly endless list of different models of heaters is extremely confusing and does not make choosing one easy. That’s why I put together the comparison chart below. It highlights the strengths, weaknesses, and differences between these heaters in a more digestible format. As you browse this table, there are some other important things you’ll want to keep in mind.
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- Pricing varies widely because heaters are sold in a variety of specialized kits. These kits are made up of equipment tailored to specific installations, for instance, trucks versus boats. They cost more than the base heaters but include crucial components like thermostat/control panels, wiring harnesses, ducting, and vents. Because of the sheer number of these different kits, I have not included them individually in this article.
- Some of the brands in this article, like Espar and Planar, are affiliated with other brands, like Eberspacher and Autoterm, respectively. Therefore, you may see the manufacturer’s names used interchangeably by retailers. I have only included the most commonly available brands (Eberspacher and Autoterm are not widely available in the North American market, based on my research).
| Eberspacher (Formerly Espar) | MSPR | Fuel Type | Voltage | Altitude Comp. | Min. Output BTU | Max. Output BTU | Min. Fuel Consumption | Max. Fuel Consumption | Initial Cost per Max. BTU |
|---|---|---|---|---|---|---|---|---|---|
| Airtronic D2 | $1,200+ | Diesel | 12- or 24-volt | 5,000 feet | 2,100 | 7,500 | .10 L/hr | .28 L/hr | $.17/BTU |
| Airtronic D4 | $1,600+ | Diesel | 12- or 24-volt | 5,000 feet | 3,400 | 13,650 | .13 L/hr | .51 L/hr | $.14/BTU |
| Airtronic B4 | $2,200+ | Gasoline | 12- or 24-volt | 5,000 feet | 4,436 | 12,970 | .18 L/hr | .54 L/hr | $.23/BTU |
| Airtronic S2-D2L | $1,200+ | Diesel | 12- or 24-volt | 10,000 | 2,898 | 7,502 | .10L/hr | .28 lL/hr | $.16/BTU |
| Airtronic M2-B4L | $2,200+ | Gasoline | 12- or 24-volt | 10,000 | 4,433 | 12,958 | .18 L/hr | .54 L/hr | $.17/BTU |
| Webasto | |||||||||
| Airtop 2000 STC | $1,500+ | Diesel | 12- or 24-volt | 7,218 feet | 3,100 | 7,000 | .12 L/hr | .24 L/hr | $.21/BTU |
| Airtop 2000 STC | $2,100+ | Gasoline | 12- or 24-volt | 7,218 feet | 3,070 | 6,800 | .14 L/hr | .27 L/hr | $.31/BTU |
| Air Top Evo 40 | $1,600+ | Diesel | 12- or 24-volt | 7,218 feet | 5,100 | 13,650 | .18 L/hr | .49 L/hr | $.12/BTU |
| Air Top Evo 55 | $1,800+ | Diesel | 12- or 24-volt | 7,218 feet | 5,100 | 18,800 | .18 L/hr | .67 L/hr | $.10/BTU |
| Air Top Evo 40 | $1,700+ | Gasoline | 12-volt | 7,218 feet | 5,800 | 13,650 | .25 L/hr | .58 L/hr | $.12/BTU |
| Air Top Evo 55 | $1,800+ | Gasoline | 12-volt | 7,218 feet | 5,800 | 18,800 | .25 L/hr | .80 L/hr | $.10/BTU |
| Planar | |||||||||
| 2D-HA | **$932+ | Diesel | 12- or 24-volt | 8200 feet | 2,700 | 6,850 | .10 L/hr | .24 L/hr | $.14/BTU |
| 44D-HA | **$1077+ | Diesel | 12- or 24-volt | 8200 feet | 3,200 | 13,600 | .12 L/hr | .49 L/hr | $.08/BTU |
Installing a Gasoline or Diesel Air Heater in your Campervan or Overland Vehicle
Installing a gasoline or diesel air heater in your campervan or overland vehicle is no small task, and it’s worth noting that some of the manufacturers listed in this article may only honor warranty claims if the heater was installed by a certified installation company.
The step-by-step installation process varies slightly from one product to the next and is outside the scope of this particular article. For those of you who plan to perform the installation work yourselves, check out this air heater installation guide by Isabelle and Antoine of Far Out Ride.If you’d like more information regarding hands-on experience using a diesel forced-air heater, read Richard’s article about his experience with the Planar 2D-HA.
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