For carriers and owner-operators, every pound matters when calculating total vehicle weight. Fuel weight affects load capacity, DOT compliance, and operating efficiency. In this article, we’ll answer exactly how much a gallon of diesel weighs and show you how OTR Solutions can help optimize your fuel spending while stabilizing your cashflow.
How Much Does a Gallon of Diesel Fuel Weigh?
On average, a gallon of diesel fuel weighs about 7.1 pounds. This is the standard estimate used across most commercial trucking calculations in the U.S. However, the actual weight can vary slightly depending on a few key factors, including the type of diesel, the temperature at the time of fueling, and even your elevation.
These variations may seem small, but they add up quickly. For example, 200 gallons of diesel in your tank could weigh over 1,400 pounds, which directly affects your total vehicle weight, fuel efficiency, and payload capacity.
That’s why truckers and fleet managers need to understand the variables behind diesel weight, especially when planning routes, balancing loads, or preparing for weigh station inspections.
Factors That Affect Diesel Weight
Diesel doesn’t always weigh exactly 7.1 pounds per gallon. A few environmental and fuel-specific factors can influence the actual weight. Here’s what to consider:
Temperature
Temperature has the biggest impact on diesel weight. According to SC Fuels, diesel and gasoline become much denser when it is cold, with about a 1% change in volume for every 19°F change in temperature. This means diesel becomes heavier in colder temperatures and lighter in warmer ones.
These temperature effects matter significantly for truckers. A large fuel tank could see weight variations of up to 50 pounds depending on temperature conditions. This matters when fueling in different climates and planning loads around legal weight limits.”
Grade of Diesel Fuel
The specific type of diesel you use can also affect its weight. There are two primary grades:
- #1 Diesel: More refined and less dense, typically used in colder climates. It weighs about 7.3 pounds per gallon.
- #2 Diesel: Denser and heavier, this is the most common fuel for commercial trucks. It weighs about 7.1 pounds per gallon.
Most truckers use #2 diesel for regular operations, while #1 diesel is typically reserved for winter conditions in northern regions.
Humidity and Altitude
These factors have minimal effect on diesel weight, but in extreme elevations or humid conditions, air pressure and vapor pressure may slightly influence fuel density. This isn’t typically a concern for day-to-day trucking operations, but is worth noting in unusual conditions.
Diesel Fuel Weight by Quantity
Here’s how diesel weight adds up as you increase the volume:
| Gallons | Estimated Weight (lbs) |
| 1 | 7.1 |
| 55 | 391 |
| 100 | 710 |
| 300 | 2,130 |
Fuel Tank Capacities by Truck Type
Different truck types carry different amounts of fuel, and that diesel weight can impact load limits and miles per gallon (MPG). Here’s a breakdown of common truck fuel capacities and weights:
| Truck Type | Fuel Capacity (Gallons) | Estimated Weight (lbs) |
| Sprinter/Cargo Van | 20-25 | 142-178 |
| Hot Shot Truck | 25-35 | 178-249 |
| Box Truck | 30-70 | 213-497 |
| Power Only | 50-100 | 355-710 |
| Dry Van Tractor | 100-150 | 710-1,065 |
| Reefer Truck | 120-200 | 852-1,420 |
| Flatbed Truck | 100-150 | 710-1,065 |
| Step Deck | 100-150 | 710-1,065 |
| Drayage Truck | 100-200 | 710-1,420 |
| Class 8 Semi w/ Dual Tanks | 200-300 | 1,420-2,130 |
Important notes:
- Fuel tank sizes vary by manufacturer and configuration
- Reefer units have separate fuel tanks, adding to the total fuel weight
- GVWR considerations are especially important for Hot Shot, Step Deck, and Sprinter operators who run close to legal weight limits
OTR Solutions works with fleets of all sizes, from independent owner-operator drivers to large fleets.
Why Diesel Weight Matters for Truckers
Diesel fuel isn’t just an expense; it’s part of your total load. Whether you’re an owner-operator or managing a fleet, knowing how much diesel weighs can help you plan smarter, stay compliant, and improve profitability on every haul.
Fuel Costs
Diesel weight directly impacts your operating expenses. The heavier your truck, the more fuel it takes to move, especially over long distances, up inclines, or through stop-and-go traffic.
Even the weight of a full fuel tank can affect your MPG, ultimately increasing the total cost of each trip. Factoring in fuel weight helps you more accurately budget and identify where you can save.
Payload Optimization
Every gallon of diesel adds about 7.1 pounds to your truck, and that weight counts against your gross vehicle weight rating (GVWR). If you’re running close to the legal weight limit, accounting for your fuel load is essential to avoid exceeding capacity.
By understanding how diesel weight factors into your total, you can better plan your loads, reduce the risk of overweight fines, and maximize revenue per haul.
Trip Planning
Fuel weight affects trip efficiency. Heavier loads decrease fuel economy, especially on steep grades or during extended idling. Factoring in diesel weight allows you to better plan routes, fuel stops, and driving strategy to keep costs low and MPG high.
Smart diesel fuel stop planning combined with tools like the OTR Fuel Finder can save you significant money over time.
Legal Compliance
DOT regulations set strict weight limits for commercial vehicles, and fuel weight counts toward your total. Even a full tank of diesel can tip you over the legal limit if your load is already near capacity. Overlooking this can lead to fines, delays at weigh stations, or forced offloading that cuts into your time and profits.
How to Calculate Diesel Fuel Costs for Your Fleet
Fuel costs go beyond just the price per gallon. Use this simple formula to estimate your true fuel expenses:
Total Trip Cost = (Trip Miles ÷ Miles Per Gallon) × Price Per Gallon
For example, if you’re traveling 500 miles, getting 6 MPG, and diesel costs $3.50 per gallon:
(500 ÷ 6) × $3.50 = $291.67
Remember that fuel weight affects your MPG. A fully loaded fuel tank will reduce your efficiency compared to running with less fuel. Finding the cheapest diesel fuel along your route can significantly impact your bottom line.
OTR Solutions: Optimize Your Fuel Spending and Cashflow
Managing fuel costs is critical for trucking success, especially when every gallon adds 7.1 pounds to your load. OTR Solutions provides the fuel savings tools you need to maximize profitability on every trip.
The OTR Fuel Card delivers average savings of $0.50 per gallon, with savings up to $2.25 per gallon at 2,500+ in-network locations. With $0 transaction fees at participating stations, you can significantly reduce your fuel expenses while maintaining optimal load weights.
Our Fuel Finder inside the OTR Mobile App helps you locate the best discounts along your route, so you can plan smarter fuel stops while considering diesel weight in your load calculations. This technology shows you exactly where to save the most, helping you balance fuel costs with weight considerations.
When you pair the OTR Fuel Card with our TRUE Non-Recourse Factoring, you unlock even greater benefits. You get same-day funding on approved and processed invoices with no chargebacks, ever, while saving money at the pump. This combination provides steady cashflow to cover fuel expenses and protects you from non-paying brokers.
These savings become even more valuable during fuel price surges when every cent per gallon counts.
Take Control of Your Fuel Costs
How much does a gallon of diesel weigh? Enough to make a real difference in how you manage loads, plan routes, and control operating costs. Temperature, fuel grade, and tank size all play a role in how diesel weight affects your day-to-day operations.
With OTR Solutions’ fuel savings and factoring services, you can take full control of your fuel spending and cashflow, without the guesswork.
Ready to save on fuel and strengthen your cashflow? Get started with OTR Solutions and see how smarter fuel management can improve your bottom line.
Frequently Asked Questions
Here are some common questions about fuel weight, along with their answers.
Does diesel weigh more than gasoline?
Yes. Diesel weighs approximately 7.1 pounds per gallon, while gasoline weighs approximately 6.2 pounds per gallon.
How does fuel weight affect my truck’s total load capacity?
Fuel weight counts toward your gross vehicle weight (GVW). When you know how much diesel you’re carrying, you can plan your loads to avoid overweight violations and maximize payload efficiency.
Can weather affect diesel fuel weight?
Yes. Diesel becomes denser in colder temperatures. Industry data shows temperature changes can create significant weight variations in fuel tanks.
Is #1 or #2 diesel heavier?
#2 diesel is heavier than #1 diesel. #1 is more refined and used in cold climates, while #2 is more common and denser, making it slightly heavier per gallon.
How can I reduce fuel-related costs as a trucker?
Use a discount fuel card, like the OTR Fuel Card, and pair it with factoring solutions to manage fuel purchases, improve cashflow, and plan cost-efficient routes.
How do I calculate the total weight of my fuel load?
Use this formula: Gallons of diesel × 7.1 = Total weight in pounds. Adjust for conditions like temperature or fuel grade if needed.
Is diesel fuel weight included in weigh station checks?
Yes. Weigh station inspections measure your truck’s total weight, which includes the weight of your fuel. Staying aware of your fuel load is essential for compliance.