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Guides, tips, and in-depth articles about fuel economy, gas mileage calculation, and saving money on fuel.

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MPG Basics and Formulas Start with MPG math, conversions, and understanding label metrics. Trip Cost and Fuel Planning Plan road-trip and commute fuel spend with practical budgeting guides. EV Efficiency and MPGe Understand MPGe, charging costs, and apples-to-apples EV comparisons. Maintenance and Driving Habits Improve real-world fuel economy with behavior and upkeep checklists.

Most Used Calculators

Gas Mileage Calculator Track real MPG or L/100km from fill-up data. Trip Gas Cost Calculator Estimate gallons needed and total trip fuel spend. Cost Per Mile Calculator Compare per-mile costs across vehicles and routes. Gas vs EV Cost Calculator Run an apples-to-apples annual cost comparison.

Showing guides 31-45 of 61 (page 3 of 5).

Latest Guides

Fuel-efficient car representing how fuel economy affects greenhouse gas emissions on the EPA label
9 min read

Fuel Economy vs Greenhouse Gas Ratings: How the EPA Label Connects Them

The EPA label includes both fuel economy (MPG) and a Greenhouse Gas (GHG) rating on a 1–10 scale. For gasoline vehicles, these are closely linked because tailpipe CO 2 emissions...

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Odometer and dashboard representing programmatic vehicle fuel economy lookups using FuelEconomy.gov web services
12 min read

FuelEconomy.gov API Guide: Pull MPG and Cost Data

FuelEconomy.gov provides XML web services endpoints that let you fetch vehicle menus (year, make, model) and vehicle details programmatically. This is useful if you're building a...

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Gas pump nozzle representing fuel consumption and gallons per 100 miles
8 min read

Gallons per 100 Miles Explained (Fuel Consumption Rate)

Gallons per 100 miles is a fuel consumption metric shown on the EPA label for gasoline vehicles. Unlike MPG, it maps directly to fuel used and therefore to fuel cost . Lower is better....

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Two vehicles representing a side-by-side comparison of gas versus electric cost per mile
10 min read

Gas vs Electric Cost Per Mile: How to Compare Fairly

A fair “gas vs EV” comparison uses the same unit on both sides: dollars per mile (or dollars per 100 miles). For gasoline, that’s gas price divided by MPG. For EVs, it’s electricity...

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Highway driving representing how to estimate driving range on a tank using MPG and tank size
10 min read

How to Calculate Driving Range on a Tank (and Add a Safety Buffer)

Driving range on a tank is a simple formula: tank size × MPG. The hard part is choosing a realistic MPG (because speed, traffic, weather, and maintenance change it) and deciding on a...

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Car dashboard and odometer representing vehicle data and fuel economy research downloads
12 min read

How to Download FuelEconomy.gov Data (CSV) for Research

FuelEconomy.gov (DOE) provides downloadable fuel-economy datasets (CSV) covering vehicle MPG, MPGe, fuel type, and related fields. It's a strong source for building comparisons,...

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Car dashboard and odometer representing looking up official fuel economy and cost data online
9 min read

How to Use FuelEconomy.gov to Compare Cars (MPG, Cost, and Labels)

FuelEconomy.gov is the U.S. Department of Energy’s official consumer site for fuel economy information, including MPG ratings, estimated fuel costs, and printable fuel economy labels for...

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Traffic stopped in the city representing engine idling and wasted fuel
9 min read

Idling Fuel Use: How Much Fuel Can Idling Burn?

Idling burns fuel while you get zero miles per gallon. DOE’s fuel-economy guidance notes that idling can use roughly one-quarter to one-half gallon of fuel per hour , and it provides a...

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Dashboard efficiency display representing electric vehicle efficiency metrics like kWh per 100 miles
9 min read

kWh per 100 Miles Explained: The EV Metric That Maps to Cost

For electric vehicles, kWh per 100 miles is a fuel-consumption metric — just like gallons per 100 miles for gasoline cars. Lower kWh/100 miles means the vehicle uses less...

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Mechanic performing vehicle service representing how motor oil choice can influence fuel economy
9 min read

Motor Oil and MPG: Viscosity, Labels, and What Matters

Motor oil affects internal friction, and using the correct viscosity is part of keeping a vehicle running as designed. FuelEconomy.gov states you can improve gas mileage by 1–2% by...

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Open highway representing planning fuel stops on a long road trip
10 min read

Planning Refuel Stops on a Road Trip: A Simple Method

Fuel-stop planning is easier when you separate trip cost from trip logistics . Cost is based on total gallons used and fuel price. Logistics is based on your realistic range on a tank,...

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Highway driving representing aerodynamic drag and the fuel economy impact of carrying cargo outside the vehicle
9 min read

Roof Cargo Box vs Rear Cargo Carrier: Which Hurts MPG Less?

Roof-mounted cargo (racks, boxes, baskets) can reduce fuel economy because it increases aerodynamic drag. A rear cargo carrier can also hurt efficiency (it still changes airflow and adds...

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Highway driving representing aerodynamic drag and roof rack fuel economy impacts
9 min read

Roof Racks and MPG: How Drag Impacts Gas Mileage

Roof racks and roof-mounted cargo boxes can reduce fuel economy because they increase aerodynamic drag. DOE’s fuel-saving guidance provides ranges for how much roof racks and cargo boxes...

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Car odometer and dashboard representing short trips and cold starts that can reduce fuel economy
9 min read

Short Trips vs Long Trips: Why Cold Starts Use More Fuel

Short trips often have worse MPG because engines spend a bigger share of the drive warming up and running less efficiently. DOE’s fuel economy guidance notes that taking several short...

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Urban traffic congestion representing smog-forming vehicle emissions and the EPA label smog rating
8 min read

Smog Rating on the Fuel Economy Label: What It Measures

The EPA fuel economy label includes a Smog rating on a 1–10 scale. It summarizes tailpipe pollutants that contribute to local air pollution (often called “smog-forming emissions”)....

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