Miles per gallon (US) to Liters per 100 km
mpg
L/100km
Conversion History
| Conversion | Reuse | Delete |
|---|---|---|
| No conversion history to show. | ||
Quick Reference Table (Miles per gallon (US) to Liters per 100 km)
| Miles per gallon (US) (mpg) | Liters per 100 km (L/100km) |
|---|---|
| 15 | 15.680972219333333333 |
| 20 | 11.7607291645 |
| 25 | 9.4085833316 |
| 30 | 7.840486109666666667 |
| 40 | 5.88036458225 |
| 50 | 4.7042916658 |
| 55 | 4.276628787090909091 |
About Miles per gallon (US) (mpg)
Miles per gallon (US) — universally abbreviated mpg in the United States — is the dominant fuel economy metric in American automotive culture. Higher mpg means lower fuel consumption. The US gallon is 3.785 liters. The US Environmental Protection Agency (EPA) publishes city, highway, and combined mpg ratings on new vehicle window stickers, and Corporate Average Fuel Economy (CAFE) standards are set in mpg. Typical US passenger cars range from 15–20 mpg for trucks and large SUVs to 50–60 mpg for modern petrol hybrids. Because mpg is an efficiency unit (not consumption), the fuel savings from improving a low-mpg vehicle far exceed the savings from improving an already-efficient one.
A Ford F-150 pickup averages about 20 mpg combined on the EPA cycle. A Toyota Camry Hybrid achieves approximately 47 mpg combined.
About Liters per 100 km (L/100km)
Liters per 100 kilometers (L/100km) is the standard fuel consumption unit across the European Union, Australia, Canada, China, and most of the metric world. It expresses how many liters of fuel a vehicle burns to travel 100 km — a lower number indicates greater efficiency. Modern petrol passenger cars range from about 4 L/100km for efficient small cars to 15 L/100km or more for large SUVs and trucks. Because the unit measures consumption rather than efficiency, its relationship with km/L and mpg is non-linear: a change from 15 to 10 L/100km saves more fuel per kilometer than a change from 6 to 5 L/100km.
A Toyota Prius averages about 4.5 L/100km under EU testing. A full-size petrol SUV typically consumes 10–14 L/100km on the combined WLTP cycle.
Miles per gallon (US) – Frequently Asked Questions
Why is EPA mpg always higher than what I actually get?
The EPA tests cars on a dynamometer in a lab, not on real roads. While EPA adjusted its formulas in 2008 to be more realistic, factors like cold weather, air conditioning, aggressive driving, hilly terrain, and short trips still cause most drivers to underperform the sticker by 10–20%.
Why does the US use miles per gallon instead of L/100km?
The US never adopted the metric system for everyday use, and mpg has been embedded in American car culture since the 1970s oil crisis when fuel economy became a selling point. CAFE standards codified mpg into federal law, making a switch politically and practically difficult.
What is the "mpg illusion" and why does it matter?
The mpg illusion is the cognitive bias where people assume equal mpg improvements save equal fuel. In reality, upgrading a truck from 12 to 14 mpg saves more gallons over 10,000 miles than upgrading a sedan from 30 to 50 mpg. This is because mpg is a reciprocal measure — savings are concentrated at the low end.
How do I convert US mpg to UK mpg?
Multiply US mpg by 1.201 to get UK mpg (because the imperial gallon is 20.1% larger than the US gallon). A car rated 30 US mpg is about 36 UK mpg. Many Americans visiting the UK are confused when British cars seem to get impossibly high mpg numbers.
What is the highest mpg car ever sold in the US?
The 2025 Hyundai Ioniq Blue held the record for non-plug-in cars at 59 mpg combined. Among hybrids, the Toyota Prius has consistently led, reaching 57 mpg combined in recent model years. Plug-in hybrids running on electricity achieve MPGe ratings over 100, but that is a different metric entirely.
Liters per 100 km – Frequently Asked Questions
Does fuel consumption increase linearly with speed, or is there a sweet spot?
There is a sweet spot, typically between 50 and 80 km/h for most cars. Below that, the engine runs inefficiently at low load. Above it, aerodynamic drag — which scales with the square of speed — dominates. At 120 km/h a car may use 7 L/100km; at 160 km/h the same car could burn 11+ L/100km. That is why the jump from 100 to 130 km/h costs far more fuel than from 70 to 100.
What L/100km should I expect in real-world driving vs the WLTP sticker?
Most drivers see 10–25% higher consumption than the WLTP rating. A car rated at 6 L/100km will likely average 6.6–7.5 L/100km in mixed real-world conditions. Cold weather, city driving, roof boxes, and aggressive acceleration all push the number up.
How do I convert L/100km to US mpg in my head?
Divide 235 by the L/100km value. So 8 L/100km is roughly 235 ÷ 8 ≈ 29 mpg. For UK mpg, divide 282 instead. This mental shortcut is accurate enough for casual comparisons when shopping for cars across markets.
Why did Europe pick 100 km as the reference distance?
One hundred kilometers is a psychologically round number that keeps consumption figures in a convenient 3–20 range for most passenger cars. Using L/km would give tiny decimals (0.07), and L/1000km would give unwieldy large ones (70). The 100 km base hits the sweet spot for human readability.
What L/100km does a diesel car achieve compared to petrol?
Diesel engines are typically 15–25% more fuel-efficient than equivalent petrol engines. A petrol car rated at 7 L/100km might have a diesel counterpart at 5.5–6 L/100km. However, diesel fuel contains about 13% more energy per liter, so the CO₂ gap is smaller than the L/100km numbers suggest.