Miles per Gallon (US) (MPG (US)) - Unit Information & Conversion

Definition

Miles per Gallon (US), often abbreviated as MPG (US) or simply MPG in the US context, is a unit of fuel efficiency used primarily within the United States customary system. It quantifies the distance in miles that a vehicle can travel using one US gallon of fuel. A higher MPG (US) value indicates better fuel efficiency.

History

MPG based on the US customary gallon (approximately 3.785 liters) became the standard measure for vehicle fuel economy in the United States many decades ago. Its prominence was solidified by government regulations, particularly the Corporate Average Fuel Economy (CAFE) standards established in the 1970s and enforced by the Environmental Protection Agency (EPA). The EPA mandates MPG testing and reporting for all new vehicles sold in the US.

Common Uses

• Official Vehicle Ratings: The primary unit used by the EPA for reporting official city, highway, and combined fuel economy figures for new vehicles sold in the US.
• Window Stickers (Monroney Label): Displayed prominently on the mandatory window stickers of new cars, allowing consumers to compare efficiency at the point of sale.
• Consumer Comparison: Widely used by American consumers to compare the fuel efficiency and potential running costs of different vehicles.
• Vehicle Advertising: Frequently highlighted in car advertisements and marketing materials within the US.
• Informal Benchmarking: The common unit used in everyday conversation about car fuel efficiency in the US.

Unit FAQs

Is a higher MPG (US) value better?

Yes, a higher MPG (US) value signifies better fuel efficiency. It means the vehicle can cover more miles for each US gallon of fuel consumed.

How is MPG (US) different from MPG (UK)?

The main difference lies in the definition of the gallon. The US customary gallon (approx. 3.785 liters) is smaller than the Imperial gallon (UK, approx. 4.546 liters). Because the UK gallon is larger, a vehicle will travel further on one UK gallon than on one US gallon, resulting in a higher MPG (UK) figure compared to the MPG (US) figure for the same vehicle. Specifically, 1 MPG (UK) ≈ 1.201 MPG (US), or conversely, 1 MPG (US) ≈ 0.833 MPG (UK).

How do I convert MPG (US) to L/100km?

To convert US Miles Per Gallon to Liters per 100 kilometers (a common metric unit where lower is better), use the formula: L/100km ≈ 235.21 / MPG (US).

How do I convert MPG (US) to km/L?

To convert US Miles Per Gallon to Kilometers per Liter (a metric unit where higher is better), use the formula: km/L ≈ MPG (US) * 0.42514.

How do I convert MPG (US) to MPG (UK)?

To convert US Miles Per Gallon to Imperial Miles Per Gallon, use the formula: MPG (UK) ≈ MPG (US) * 1.20095.