Gasoline weight per gallon is an important measurement for everyone who working with fuel, whether for vehicles, storage, or industrial use. Most drivers are always curious about gasoline weight, and many still don’t have any knowledge about it in pounds, liters, and barrels. The mechanics guide will solve this confusion, and reading it will surely make you aware of gasoline weight.
Many Americans think one gallon of gasoline is equal to the weight of water. It is an absolutely false calculation. Gasoline has a different weight per gallon compared to water because of its density. Let’s have all the information mentioned below.
How Much Does a Gallon of Gasoline Weigh?
One U.S. gallon of gas has an average weight of 6.0 pounds. Its weight in kilograms is 2.72 at 59°F (15°C). One gallon of gas is equal to 3.78 liters. One gallon of gas weighs less than water. One gallon of water has a weight of 8 pounds. This is because water’s density is greater than gasoline’s.
The molecules of water are tightly attached to one another, while gasoline molecules are less tightly bound to each other. Water’s density is about 1.0 g/cm³ (8.34 pounds per gallon). Gasoline’s density is about 0.72–0.76 g/cm³ (around 6.1–6.3 pounds per gallon).
Gasoline Grades in U.S. Gas Stations
In the U.S., the majority of gas stations offer three types of gasoline for customers. These are classified by octane levels. A high octane level reduces car engine knocking, and the higher the octane level, the better the car’s engine performance.
The three types are Regular (87 octane), Midgrade (89–90 octane), and Premium (91–94 octane). Luxury and latest model users opt for premium gasoline in the U.S., as it gives them a higher fuel average and better engine performance.
How Temperature Affects Gasoline Weight Per Gallon
Gasoline is greatly affected by temperature. In summer, you may notice that your fuel average is greatly disturbed, and you get a lower fuel average in summer. This is because gasoline expands in summer and contracts in the cold.
It means that at high temperatures, fuel weight goes down, and in cold weather, fuel becomes denser and heavier per gallon. An example is that in cold winter (30°F) gasoline weighs 6.42 lbs per gallon, while in summer (85°F) it weighs 5.93 lbs per gallon.
Fuel Tank Capacities in Different Vehicle Categories
Small cars have fuel tank capacities ranging from 13 to 15 gallons (45–57 liters), whereas some have 16 to 20 gallons (60–76 liters). Trucks or SUVs have larger tanks for more power and long traveling, ranging from 22 to 27 gallons (83–102 liters).
Trucks can have larger capacities of 30 gallons because of heavy-duty work. Every car segment has its own gasoline capacity in its tank. The fuel average of each car depends on different factors like speed, quality of the gasoline, and the car’s engine performance.
Diesel vs. Gasoline: Which Weighs More?
One gallon of diesel weighs more than gasoline. This is because the molecules of diesel are heavier than those of gasoline. Diesel has more density than gasoline. Many drivers think that every fluid has the same weight, but this is not true.
Weight depends on density—the higher the density, the higher its weight will be. Gasoline weighs 6.0 pounds per gallon, while diesel weighs 7.0 pounds. Diesel engines are more fuel-efficient because diesel contains molecules with more energy.
| Fuel Type | Lbs per Gallon | Kg per Gallon | Lbs per Liter | Kg per Liter |
| Gasoline | ~6.0 | ~2.72 | ~1.59 | ~0.72 |
| Diesel | ~7.0 | ~3.18 | ~1.85 | ~0.84 |
Fuel in Barrels
In the oil and fuel industry of the U.S., the term “U.S. barrel” is always used. A U.S. barrel is a standard measure of 42 U.S. gallons. The weight of a barrel depends on the fuel type because gasoline weight will be different from diesel weight. Let’s have a close look:
Gasoline in a barrel
42 gallons × 6.0 lbs/gallon ≈ 252 lbs (≈114 kg) of gasoline
Diesel in a barrel
42 gallons × 7.0 lbs/gallon ≈ 294 lbs (≈133 kg) of diesel
Note: An empty steel barrel typically weighs 35–40 lbs, or 16–18 kg.
How Fuel Weight Affects Your Vehicle
Fuel has weight. When you have a full tank, it means you have the weight of a person on your vehicle. A full tank has an average capacity of 20 gallons, which is equal to the weight of a person. This means your engine will have more weight to carry. It will affect your fuel efficiency, but it only slightly affects your consumption (about 1%).
If you run your vehicle on low fuel, it can harm your car’s fuel pump. So we suggest you ignore the idea that fuel weight significantly affects fuel consumption. Always have maximum fuel in your car’s tank.
Conclusion
Gasoline weight per gallon is different from other liquid weights because of its density. Gas has low density, while diesel weighs more because of its high density. Although many drivers get confused about the weight of gas, we try our best to make you familiar with this issue. We always suggest having maximum fuel in your tank so your fuel pump does not get clogged.
