Fuel Tank Maintenance: When To Replace Your Semi Truck's Tank

Semi-trucks are enormous vehicles that carry most of the goods we use daily. The distance they can cover depends on their fuel tank capacity, which varies depending on the make, model, and year of the truck. Generally, a semi-truck's fuel tank capacity ranges from 100 to 300 gallons of diesel, with some trucks having dual tanks that allow them to store twice as much fuel. So, when should you consider changing the fuel tank on your semi-truck?

Standard semi-truck tanks hold 105 gallons of fuel

The size of a semi-truck's fuel tank is important as it determines how much fuel the truck needs and how far it can travel without refuelling. A semi-truck with a standard 105-gallon tank can travel approximately 682.5 miles (6.5 miles per gallon) before needing to refuel.

Some semi-trucks have multiple fuel tanks, which allow them to travel longer distances. Additionally, the weight of the fuel and the tank itself is a factor in how far a semi-truck can travel. A standard semi-truck tank filled with fuel weighs around 735 pounds.

It is also important to consider the 95% rule when fuelling a semi-truck. This means filling the tank to only 95% of its capacity to avoid spills and allow for fuel expansion. By following this rule, you can help ensure the safety of those on the road and reduce the risk of fuel spills, which can harm the environment.

Custom tanks can hold 160, 260 or 400 gallons

The fuel tank capacity of a semi-truck is an important consideration for fleet managers and truck operators. The size of the fuel tank will determine how frequently the truck will need to stop for refuelling and how far it can travel. While a typical semi-truck with a standard configuration has a fuel tank capacity of around 105 gallons, custom tanks can be installed to increase this capacity significantly.

Customised semi-truck fuel tanks are available in various sizes, with the most common capacities being 160 gallons, 260 gallons, and 400 gallons. These larger tanks offer several benefits for businesses, especially those that require their trucks to travel greater distances without frequent refuelling stops. With a custom tank, the truck can cover more ground before needing to refuel, improving efficiency and reducing downtime.

It is worth noting that while larger fuel tanks provide the advantage of extended travel range, they also contribute to the overall weight of the vehicle. The Federal Motor Carrier Safety Administration (FMCSA) has established weight restrictions for semi-trucks, and the weight of the fuel and tanks can impact compliance with these regulations. A gallon of diesel fuel typically weighs about 7 pounds, so fuel tank capacity can significantly affect the overall weight of the truck, especially when the tanks are filled to capacity.

To optimise fuel efficiency and reduce the risk of spills, it is generally recommended that semi-truck fuel tanks be filled to 95% of their capacity. This allows for fuel expansion and contraction due to temperature changes and helps to avoid overflow. Additionally, it is advisable to maintain a minimum of 25% fuel in the tank to prevent contaminants like dirt and bacteria from accumulating at the bottom, which could damage internal components such as the engine, fuel pump, and catalytic converter.

By understanding the available options for custom fuel tanks and considering the specific operational requirements of their fleet, managers can make informed decisions about the appropriate tank size. This ensures that their semi-trucks have the necessary fuel capacity to meet their business needs while complying with weight restrictions and maintaining optimal fuel efficiency.

Trucks with dual tanks can store twice as much fuel

Semi-trucks are used for long-distance travel and have a special trailer attached to the back for carrying large loads of goods. They are far more complex than the average vehicle, and while most vehicles have a single tank, semi-trucks have multiple.

Semi-trucks usually have two diesel tanks on either side of the tractor, with each tank holding about 120-150 gallons of fuel. This means trucks with dual tanks can store twice as much fuel as those with a single tank. Each tank holds about 125-150 gallons each, which averages out to about 300 gallons in total. This equals about 2,000 miles on a full tank of diesel if travelling at a relatively steady pace and on even ground.

The dual-tank system is necessary to keep the truck balanced on the road, as one tank on one side can lead to tilting or falling. The tanks are usually mounted on opposite sides of the frame rails, with a balancing system to ensure equal weight distribution. The pump pulls fuel from both tanks to ensure a balanced weight in the truck. The tanks are filled evenly at the pump, but the valve to the second tank must be open. There is usually a self-balancing device within the tank that helps to ensure even distribution between them.

Dual fuel tanks are not mandatory, but they offer several benefits, such as flexibility, cost savings, and quality fuel access. They allow drivers to switch between different fuel types depending on availability or need.

The 95% rule: don't fill tanks past 95% capacity

The 95% rule is a recommendation for semi-truck drivers, operators, and fleet managers to fill their tanks to 95% capacity. This rule is in place to help avoid several issues that can arise from filling a tank to 100% capacity.

Firstly, filling a tank past 95% can lead to spills. Leaving a little room for air inside the tank prevents diesel fuel from spilling out through overflow valves. Spilled fuel is not only harmful to the environment but also poses health and safety risks for nearby drivers.

Secondly, diesel fuel expands and contracts based on temperature changes. As diesel fuel expands, it can lead to fuel inefficiency as the suction components are not designed to process excess fuel from the bottom of the gas tank. Driving in colder temperatures with a tank filled to maximum capacity can result in water in the fuel lines, preventing gasoline from reaching the engine.

Adhering to the 95% rule can also help with fuel management and weight restrictions. Knowing that your tanks are consistently filled to 95% capacity can provide insights into how to better manage your fleet and stay within weight restrictions set by the Federal Motor Carrier Safety Administration (FMCSA) and the Department of Transportation (DOT).

Additionally, the 95% rule is complemented by the 25% rule, which suggests not allowing fuel tanks to fall below 25% capacity. This is because contaminants like dirt and bacteria can build up at the bottom of a fuel tank, and driving with a near-empty tank can damage internal components such as the engine, fuel pump, and catalytic converter.

By following these best practices, you can ensure your semi-trucks remain in good condition and continue to operate efficiently for many miles to come.

The 25% rule: don't let tanks fall below 25% capacity

The 25% rule is an important guideline for semi-truck drivers and fleet managers to ensure the optimal performance and longevity of their vehicles. By not letting fuel tanks fall below 25% capacity, drivers can avoid a range of issues and maintain the health of their fleet.

Firstly, letting a fuel tank fall below 25% can lead to a build-up of contaminants like dirt and bacteria at the bottom of the tank. Operating a truck with a nearly empty tank can cause these contaminants to be drawn into the engine, fuel pump, and catalytic converter, potentially damaging these critical components. This can result in reduced engine performance and even engine failure over time.

Secondly, the 25% rule helps to ensure optimal fuel efficiency. Diesel fuel expands and contracts based on temperature changes. By maintaining a fuel level above 25%, drivers can avoid the risk of fuel expansion causing issues with the suction components, which are not designed to process excess fuel. Driving with a very low fuel level can lead to fuel inefficiency and even engine problems if the fuel lines become clogged.

Additionally, the 25% rule is a safety precaution to prevent spills and leaks. By always refuelling before the tank falls below 25%, drivers reduce the risk of spills from overfilling. Spilled fuel not only poses a health and safety risk to those nearby but can also be harmful to the environment.

Finally, adhering to the 25% rule helps to ensure the longevity of the semi-truck's engine. By consistently refuelling above this threshold, drivers can avoid the potential issues associated with running a vehicle on a nearly empty tank, such as contaminant build-up and fuel inefficiency. This simple practice can extend the lifespan of the engine and delay the need for costly repairs or replacements.

In conclusion, the 25% rule is a critical guideline for semi-truck operations. By refuelling before fuel tanks fall below 25% capacity, drivers can maintain fuel efficiency, avoid engine problems, prevent spills, and extend the lifespan of their vehicles. This simple practice can have significant benefits for the performance and longevity of semi-trucks.

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