Semi Truck Fuel Tank Size and Range
Tank sizes the makers publish, and how far a full tank goes
There is no single semi truck fuel tank size. Makers offer more than one setup, so the size depends on how the truck was built. International's LT Series brochure lists single tanks of 70 to 120 gallons and dual tanks of 70 to 140 gallons. To find how far a full tank goes, multiply the tank gallons by your miles per gallon.
Figures come from the makers' own documents, the Peterbilt manual and the federal rule. Last reviewed November 3, 2026.
How big is a semi truck fuel tank?
Here is what each maker says about tank size on the six truck models in our truck model specs. Only International lists tank sizes.
| Truck | What the maker says about tank size | What we read |
|---|---|---|
| International LT Series | Sleeper brochure: single tanks of 70 to 120 gallons and dual tanks of 70 to 140 gallons, aluminum (polished or non-polished), mounted back of cab. The brochure does not say whether the dual range is each tank or the total. The LT Series web page lists dual tanks of 70 to 120 gallons and of 70 to 140 gallons. | 2024-25 LT Series sleeper specifications brochure and the LT Series page |
| Peterbilt 579 | Lists no tank sizes. The operator's manual says a truck may be built with different fuel systems and draw tube locations, and it gives fuel level and refueling rules (see below). | Model 579 page and the 2024 Model 579 Operator's Manual |
| Freightliner Cascadia | Lists no tank sizes. The specifications page covers engines, transmissions, axles, suspensions and features. | Cascadia specifications page |
| Volvo VNL | Lists no tank sizes on the VNL page, in the VNL product guide or in the trim level guide. | VNL page, VNL product guide brochure and trim level guide |
| Mack Anthem | Lists no tank sizes on the Anthem page or in the four-page Anthem spec sheet. | Anthem page and four-page spec sheet |
| Kenworth T680 | Lists no tank sizes on the T680 page. | T680 page |
A model page that leaves tank sizes out does not mean the truck has one size. Dealers give a written spec for each truck, and that spec shows the tanks it was built with. Ask for yours.
How far can a semi truck go on a full tank?
Range is simple math. Multiply the gallons the tanks hold by your miles per gallon. A truck that holds 200 gallons and gets 7 mpg covers about 1,400 miles on a full tank.
| Tank size | At 6 mpg | At 7 mpg | At 8 mpg |
|---|---|---|---|
| 100 gallonsabout 379 litres | 600 / 450 mi | 700 / 525 mi | 800 / 600 mi |
| 150 gallonsabout 568 litres | 900 / 675 mi | 1,050 / 788 mi | 1,200 / 900 mi |
| 200 gallonsabout 757 litres | 1,200 / 900 mi | 1,400 / 1,050 mi | 1,600 / 1,200 mi |
| 250 gallonsabout 946 litres | 1,500 / 1,125 mi | 1,750 / 1,313 mi | 2,000 / 1,500 mi |
| 300 gallonsabout 1,136 litres | 1,800 / 1,350 mi | 2,100 / 1,575 mi | 2,400 / 1,800 mi |
Each cell shows miles on a full tank, then miles to one-quarter tank. Peterbilt's 2024 Model 579 manual advises against running below one-quarter of the truck's fuel capacity. The second number in each cell is the miles to that point: three-quarters of the full-tank miles.
The sizes and mpg in this table are examples for the math. They are not average tank sizes, and they are not typical mpg for any truck. Your mpg changes with load, speed, road and engine, so use your own number.
Get your own mpg from fill-ups with the MPG and speed calculator, then plan a whole trip with the Fuel Range and Stop Planner.
What does a maker's manual say about fuel level and refueling?
These points come from the Peterbilt 2024 Model 579 Operator's Manual. They are one maker's advice. Your own truck's manual comes first.
- Do not run below one-quarter of the truck's fuel capacity. The manual says trucks can be built with different fuel systems and draw tube locations, and that road crown matters. A tank below one-quarter could leave too little fuel to keep the engine running.
- Keep the tanks at least half full to reduce condensation of moisture in the tanks.
- When you park, fill the tanks to 95 percent of capacity. Air space in a tank lets water condense, and a fuller tank has less air.
- On a truck with more than one tank, add about the same amount of fuel to each tank.
- The manual describes a fuel crossover line between the tanks, with shut-off valves on the bottom of the secondary tank. They are optional on the primary tank.
- Do not carry extra fuel containers in the truck. Full or empty, they can leak or explode.
What does the federal rule say about fuel tanks?
Federal safety rules for fuel tanks are in 49 CFR 393.67. Paragraph (a) sets which tanks it covers, by date, position and vehicle type. For the tanks it covers:
- A tank that holds more than 25 gallons of fuel must have a venting system (paragraph (c)(8)).
- A tank body that is readily visible once installed must be plainly marked with its liquid capacity (paragraph (c)(11)).
- Each fuel tank must have a nonspill air vent, such as a ball check (paragraph (c)(10)).
More rules for your truck are in the FMCSA and DOT regulations reference.
How do I find my own tank size?
- Read the label on the tank. The federal rule above calls for the capacity to be marked on a tank body you can see once it is installed.
- Ask the dealer for the written spec or build record for your truck. It lists the tanks the truck was built with.
- Type the gallons into the Fuel Range and Stop Planner. It works out how many stops a trip needs and when to fill up.
Once you know your range, price the fuel with the fuel cost calculator and check diesel prices by region. Your engine matters too. See the engine specs reference.
What is not published about semi truck fuel tanks?
- Most makers do not list tank sizes on their model pages. That is why only one maker's numbers appear in the table above.
- We found no maker or agency that publishes an average tank size for semi trucks, so this page does not give one. Parts sellers and blogs quote totals, but those are not maker documents, so we do not repeat them.
- The documents we read give no tank dimensions or tank weights.
- We found no source that gives one typical miles per gallon for all trucks. The range table uses example numbers, not averages.
- Fuel adds weight. This page does not state what a gallon weighs, because the sources we read do not. Check your axle weights with a full load of fuel.
Semi truck fuel tank frequently asked questions
How big is a semi truck fuel tank?+
It depends on how the truck was built, so there is no one answer. International's LT Series sleeper brochure lists single aluminum tanks of 70 to 120 gallons and dual aluminum tanks of 70 to 140 gallons. The other makers we checked do not list tank sizes on their model pages. Check the label on your own tank.
How many gallons of fuel does a semi truck hold in total?+
Add up the gallons on each tank's label. A truck with one 150-gallon tank holds 150 gallons. A truck with two 100-gallon tanks holds 200. International's brochure does not say whether its 70 to 140 gallon dual range is each tank or the total, so ask the dealer for the spec of your truck.
How far can a semi truck go on a full tank?+
Multiply the gallons the tanks hold by your miles per gallon. A truck that holds 200 gallons and gets 7 mpg covers about 1,400 miles on a full tank. Peterbilt's manual advises against running below one-quarter of fuel capacity, so plan to stop after about 1,050 miles. Your mpg changes with load, speed and road, so use your own number from the MPG calculator.
How big is a semi truck fuel tank in litres?+
One U.S. gallon is 3.785 litres. So 70 gallons is about 265 litres, 120 gallons is about 454 litres, and 140 gallons is about 530 litres.
Are semi truck fuel tanks connected?+
On the Peterbilt 579, yes. The operator's manual describes a fuel crossover line between the tanks, with shut-off valves on the bottom of the secondary tank. The manual also says to add about the same amount of fuel to each tank when you refuel. Other makers may build it differently, so read your own manual.
Where is the fuel tank on a semi truck?+
On the International LT Series, the aluminum tanks are mounted back of cab. Peterbilt says the 579 has tip-out chassis fairings that give tool-free access to the batteries, fuel tanks, auxiliary power units and after-treatment systems.
How full should I keep a semi truck's fuel tanks?+
This is one maker's advice, from the Peterbilt 2024 Model 579 manual. Do not run below one-quarter of fuel capacity. Keep the tanks at least half full to reduce condensation. When you park, fill them to 95 percent of capacity. Your own truck's manual comes first.
How often does a semi truck need to refuel?+
Divide the miles of your trip by the miles you get from a tank down to your reserve. A 200-gallon truck at 7 mpg that stops at one-quarter tank has about 1,050 miles between fills. The Fuel Range and Stop Planner works out the stops for a whole trip.
Sources for semi truck fuel tank sizes
- International LT Series 2024-25 sleeper specifications brochure (PDF)
- International LT Series page
- Peterbilt 2024 Model 579 Operator's Manual (PDF)
- Peterbilt Model 579 page
- 49 CFR 393.67: Liquid fuel tanks (eCFR)
- Freightliner Cascadia specifications (reviewed, lists no tank sizes)
- Volvo VNL page (reviewed, lists no tank sizes)
- Mack Anthem page (reviewed, lists no tank sizes)
- Kenworth T680 page (reviewed, lists no tank sizes)
Want fewer fuel stops to plan? Let a dispatcher handle the rest.
Grow Trucking finds loads, plans the route, negotiates rates and does the paperwork for owner-operators and small fleets. Tell us about your truck and we will show you how we can help.
Also: About Grow Trucking · Refer a carrier · Trucking blog
Tank sizes depend on the model year and how each truck was ordered. Confirm the tanks on a specific truck against its label, its written spec and the maker's current documents before you plan a trip around them.
Free tools for planning fuel
Work out your real mpg, plan your fuel stops, price the fuel for a trip and check your axle weights with fuel on board.
- Fuel Range and Stop PlannerType in your tank size and mpg to see how many fuel stops a trip needs.
- MPG and Average Speed CalculatorWork out your real mpg from fill-ups, then use it in the range table.
- Fuel Cost CalculatorPrice the fuel for a whole trip, gallon by gallon.
- Weight & Axle Load CalculatorFuel adds weight. Check your axle weights with the tanks full.