FreightWaves Ratings cuts through the noise of freight technology product reviews to make you a smarter buyer

What is Reefer Fuel?

If you drive a refrigerated tractor-trailer, you need two kinds of fuel to power your truck. Standard diesel fuels the engine, but another component needs fueling — the refrigeration system. Reefer fuel is a special type of tax-exempt diesel for off-road and refrigerated trailer use. 

How Does Fueling a Reefer Trailer Work?

A reefer truck is a temperature-controlled truck made for transporting perishable cargo. Unlike dry van trucking, where drivers only need to refuel their main diesel tanks to run their truck’s engine, reefers have a designated fuel tank for running the trailer’s refrigeration system. 

Refrigerated trailers use a separate engine and insulation to control the temperature inside the trailer. The reefer system is comprised of a compressor, evaporator and condenser to actively cool the space like a giant refrigerator and keep contents at the desired temperature. 

At the pump, refrigerated truck drivers typically fill their main tanks first, then move on to their reefer fuel. They pull forward so that the tank on the trailer lines up with the designated hose and nozzle. If drivers only need reefer fuel, they can inform the attendant, and they will direct them where to go.

The reefer tank is usually located below the trailer, but can also be in the middle, off to the side or in the rear. The refrigeration system needs to be powered down to fuel. Once the reefer tank is full, drivers restart it and are on their way. 

How Much Does Reefer Fuel Cost?

Like diesel or gasoline, reefer fuel costs vary across the United States. However, since it isn’t subject to International Fuel Tax Agreement (IFTA) taxation, it’s less expensive than regular diesel. As of December 2022, the national average cost was $2.74 per mile.

How Long Does a Tank of Reefer Diesel Last?

Reefer trucks burn around 0.75 gallons of fuel per hour, and most reefer fuel tanks have a 50-gallon capacity. Therefore, reefer tanks need to be filled every 2 to 4 days. Since refrigerator units are closed systems, driving behavior does not affect fuel consumption. A poorly maintained or older unit will require more reefer fuel, as can freight requirements. 

How Much Fuel Does a Reefer Use for a Day?

Reefer systems vary widely in efficiency, burning anywhere from half a gallon to a gallon of reefer fuel per hour. Assuming a driver maxes out their hours of service (HOS) 11-hour consecutive driving limit, 5.5 to 11 gallons would be used. In a 24-hour period, refrigerated trucks use an average of 18 gallons of reefer fuel. 

Where Can You Get Reefer Fuel?

Nearly all gas stations that service diesel trucks have reefer fuel available. In a pinch, ATV service and sales companies are other options, as this fuel is also used to power many off-road vehicles. 

Understanding Taxes

Since reefer fuel is not used for on-road operations, it’s not subject to the same government highway fuel taxes. This tax exemption is the main benefit compared to using regular diesel in the refrigeration system. 

However, drivers need to be aware and extremely careful not to use reefer fuel to power a vehicle operating on public roads. If you’re caught using it for your engine, fines can reach as high as $10,000.

How Reefer Fuel Differs from Diesel

Reefer fuel differs from standard diesel, including cost, taxes, use and color. 

Cost

Reefer fuel is less expensive per gallon than regular diesel. This difference in cost is the main reason that people use this fuel for private land use, such as on work sites or at home, and some try to get away with using it on-road despite the risk of fines. 

Taxes

On-road diesel in the U.S. can be taxed as much as $0.50 per gallon after state and federal taxes. Conversely, reefer fuel is not subject to this tax and isn’t included in the IFTA filing requirements when it’s used to power a refrigerated trailer unit. 

It can also qualify for federal and state tax refunds at the end of the year, so drivers and refrigerated truck companies should be sure to keep receipts. 

Purpose

Reefer fuel is restricted to use in off-road situations, meaning you cannot use it to power a vehicle’s engine on a public road. However, these restrictions don’t apply when used for powering the refrigeration unit of a trailer. 

Besides maintaining temperature control in refrigerated trailers, it is also used in construction, agriculture and other off-road equipment on private land. 

Color

The chemical composition of reefer fuel is nearly identical to regular diesel, except that it’s dyed red. Reefer fuel’s red color has two purposes — avoiding confusion with regular diesel and quickly proving illegal use. It’s easy to detect dye by using a blacklight, and the only way to get rid of the dye is by diluting it over time with regular diesel.

Filling Up Your Tank

Transporting temperature-controlled cargo comes with the added responsibility of maintaining and fueling your refridgerator truck tank. But armed with a better understanding of reefer fuel, refrigerated truck drivers can successfully haul high-value loads.

FAQ

What fuel do reefers use?

The refrigeration unit in a reefer truck uses reefer fuel, a type of red-dyed diesel. A reefer truck’s engine is powered by regular diesel, just like other commercial trucks. 

Is tractor fuel and reefer fuel the same?

Reefer fuel and tractor fuel are significantly different. Reefer fuel is mainly used to power truck refrigeration units but can be used in other off-road situations. Tractor fuel is a standard number 2 diesel approved for public road use.  

What happens if a reefer runs out of fuel?

If a reefer unit runs out of fuel, the refrigeration generators will shut down, and the temperature-sensitive goods inside will spoil. It can also be difficult to restart a reefer unit after running out of fuel, so it’s best to maintain at least a quarter tank of reefer fuel at all times. 

Sign up for a FreightWaves e-newsletter to stay informed of all news and trends impacting supply chain careers and operations.

Hyper-Secure Fleet Cards - With Discounts Everywhere!

AtoB helps businesses take control of their biggest expenses – people, fuel and vehicles.