Vehicle Profile
Enter your vehicle details to calculate fuel costs accurately.
Station Price Comparison
Enter prices from up to 3 stations to compare cost per fill-up and annual fuel expenses.
Savings Calculator
See how much you save per fill-up and per year by choosing the cheapest station.
Fuel Economy Tips and Buying Guide
How to Save Money on Gas
Fuel is one of the largest recurring expenses for drivers. Even small price differences between stations add up over time. A $0.10 per gallon difference on a 14-gallon tank saves $1.40 per fill-up, which amounts to over $70 per year if you fill up weekly. Shopping around and using price comparison tools can lead to meaningful annual savings.
Understanding Fuel Grades
Most gas stations offer three grades of gasoline: regular (87 octane), mid-grade (89 octane), and premium (91-93 octane). Unless your vehicle's owner manual specifically requires premium fuel, using regular unleaded is perfectly fine and saves you $0.30 to $0.60 per gallon. Higher octane does not improve performance or fuel economy in engines designed for regular fuel.
Diesel vs. Gasoline
Diesel engines typically deliver 25-35% better fuel economy than comparable gasoline engines. However, diesel fuel often costs more per gallon. When comparing total fuel costs, factor in the higher MPG rating of diesel vehicles. For high-mileage drivers, diesel can be more cost-effective despite the higher per-gallon price.
Driving Habits That Improve Fuel Economy
- Maintain steady speeds: Use cruise control on highways. Frequent acceleration and braking can reduce fuel economy by 15-30%.
- Reduce idling: Idling wastes fuel. If you are stopped for more than 60 seconds, turn off the engine.
- Check tire pressure: Under-inflated tires increase rolling resistance. Keeping tires at the recommended pressure improves MPG by up to 3%.
- Remove excess weight: Every 100 pounds of extra weight reduces fuel economy by about 1%. Clear out unnecessary cargo.
- Plan routes efficiently: Combine errands and avoid peak traffic hours to reduce stop-and-go driving.
When to Fill Up
Gas prices tend to be lowest early in the week (Monday through Wednesday) and highest on weekends. Prices also fluctuate seasonally, with summer blends costing more due to stricter environmental regulations. Filling up in the morning when fuel is cooler gives you slightly denser fuel per gallon, though the difference is minimal with modern underground storage tanks.
Gallons vs. Liters
In the United States, fuel is sold by the gallon (3.785 liters). In most other countries, fuel is priced per liter. When comparing international fuel prices, remember that 1 US gallon equals approximately 3.785 liters. This calculator supports both units so you can compare prices regardless of your location.
How to Use the Fuel Price Comparison Calculator
What This Tool Does
This calculator helps you compare fuel prices across different gas stations, estimate your cost per fill-up, and calculate annual fuel expenses based on your driving habits. Whether you are choosing between two stations down the street or deciding if a cheaper station across town is worth the drive, this tool gives you the actual dollar figures to make a smart decision.
Step-by-Step Instructions
- Start by entering your vehicle profile: fuel type (regular, mid-grade, premium, or diesel), tank size in gallons, weekly miles driven, and your vehicle's fuel economy in MPG.
- Scroll to the Station Price Comparison section and enter the name and price per gallon for up to three gas stations you are comparing.
- Click "Compare Prices" to see a side-by-side breakdown of cost per fill-up and annual fuel cost for each station.
- Check the Savings Calculator section to see exactly how much you save per fill-up and per year by choosing the cheapest station.
Understanding MPG and Fuel Economy
MPG (miles per gallon) measures how far your vehicle travels on one gallon of fuel. A higher MPG means better fuel efficiency and lower costs. You can find your vehicle's rated MPG on the EPA sticker (for new cars) or by dividing miles driven by gallons used at your last fill-up. Real-world MPG often differs from the EPA rating depending on your driving style, terrain, and traffic conditions.
Gas vs. Diesel vs. Hybrid
Diesel engines typically deliver 25-35% better fuel economy than gasoline engines, but diesel fuel costs more per gallon. For high-mileage drivers (over 15,000 miles per year), diesel can still be cheaper overall. Hybrid vehicles combine a gasoline engine with an electric motor, achieving 40-60 MPG in many models. To compare total cost of ownership, factor in the vehicle purchase price alongside the annual fuel savings.
Tips for Reducing Fuel Costs
- Keep your tires inflated to the recommended pressure. Under-inflated tires increase rolling resistance and can reduce fuel economy by up to 3%.
- Use cruise control on highways to maintain a steady speed and avoid the fuel waste of constant acceleration and braking.
- Avoid premium fuel unless your vehicle specifically requires it. Using premium in an engine designed for regular provides no performance or efficiency benefit.
- Fill up early in the week (Monday through Wednesday) when gas prices tend to be lowest.
Frequently Asked Questions
How do I calculate my cost per mile?
Divide the price per gallon by your vehicle's MPG. For example, at $3.50 per gallon with a 28 MPG car, your cost per mile is $3.50 / 28 = $0.125 per mile. This is useful for estimating trip costs or comparing the running costs of different vehicles.
Is it worth driving farther for cheaper gas?
It depends on the price difference and the distance. A $0.10 per gallon savings on a 14-gallon tank saves you $1.40 per fill-up. If the cheaper station is 10 miles out of your way (20 miles round trip), you will burn about 0.7 gallons getting there and back at 28 MPG, costing roughly $2.45 -- making the trip a net loss. Use this calculator to run the numbers for your specific situation.
Does driving speed affect fuel economy?
Yes, significantly. Most vehicles achieve peak fuel efficiency between 45-65 MPH. Above 65 MPH, aerodynamic drag increases rapidly, and fuel economy drops by roughly 1-2% for every MPH over 65. Driving at 75 instead of 65 can reduce your MPG by 10-15%.
Should I use regular or premium fuel?
Check your owner's manual. If it says "regular unleaded recommended," using premium provides no benefit and wastes $0.30-$0.60 per gallon. If it says "premium required," you should use premium to avoid engine knock and potential damage. Some vehicles say "premium recommended" -- these can run on regular but may see slight performance or efficiency gains on premium.
What is the difference between gallons and liters?
One US gallon equals 3.785 liters. The United States prices fuel per gallon, while most other countries use liters. You can toggle between gallons and liters at the top of this calculator. When comparing international fuel prices, remember to convert both the volume unit and the currency for an accurate comparison.