Gas Mileage Calculator

A gas mileage calculator is a mathematical framework used to determine the exact rate at which a vehicle consumes fuel or electrical energy over a specific distance, directly translating energy efficiency into financial costs and environmental impacts. Understanding this concept is critical for modern consumers and fleet managers alike, as it empowers them to accurately budget for travel, evaluate the true total cost of vehicle ownership, and minimize their carbon footprint. By mastering the underlying formulas, variables, and physics of fuel economy, you will learn how to accurately track vehicle efficiency, compare traditional internal combustion engines against modern electric vehicles, and implement expert strategies to drastically reduce your transportation expenses.

What It Is and Why It Matters

Gas mileage, most commonly expressed in the United States as Miles Per Gallon (MPG), is the fundamental metric of vehicle energy efficiency, representing the distance a vehicle can travel on a single unit of fuel. At its core, a gas mileage calculation is a ratio that divides distance traveled by energy consumed, providing a standardized baseline to evaluate how effectively a machine converts chemical or electrical potential energy into kinetic motion. This concept exists to solve a critical problem in personal and commercial economics: transportation is inherently energy-intensive, and without a standardized way to measure energy consumption, it is impossible to predict the cost of travel or evaluate the efficiency of different machines. For a 15-year-old learning to drive, gas mileage is the difference between spending $20 or $50 to drive to a neighboring city; for a multinational logistics company, a fraction of a mile per gallon dictates millions of dollars in annual operating margins.

Beyond simple budgeting, mastering gas mileage calculations is essential for diagnosing vehicle health and understanding macroeconomic energy trends. A sudden, unexplained drop in a vehicle's calculated fuel economy is often the first mechanical warning sign of failing oxygen sensors, underinflated tires, or a dragging brake caliper. Furthermore, as the world transitions toward sustainable energy, gas mileage calculations have expanded to include electric vehicles (EVs) and plug-in hybrids, requiring consumers to translate kilowatt-hours (kWh) into standardized gasoline equivalents to make informed purchasing decisions. Ultimately, understanding gas mileage allows you to pierce through the marketing claims of automobile manufacturers, calculate your precise operational costs down to the cent, and take absolute control over one of the largest financial liabilities in the average household budget.

History and Origin of Fuel Economy Measurement

The formal measurement of fuel economy was born out of geopolitical crisis and economic necessity rather than environmental altruism. In the early days of the automobile, such as the era of the 1908 Ford Model T (which achieved a surprisingly respectable 13 to 21 MPG), fuel was cheap and efficiency was an afterthought compared to reliability and power. However, the landscape of automotive efficiency changed permanently in October 1973, when the Organization of Arab Petroleum Exporting Countries (OAPEC) proclaimed an oil embargo. The price of oil quadrupled globally from roughly $3.00 to $12.00 per barrel almost overnight, leading to severe gas shortages, rationing, and miles-long lines at fuel pumps across the United States. This crisis exposed the extreme vulnerability of a transportation infrastructure built entirely around gas-guzzling vehicles that routinely averaged fewer than 13 miles per gallon.

In direct response to this crisis, the United States Congress passed the Energy Policy and Conservation Act of 1975, a landmark piece of legislation that established the Corporate Average Fuel Economy (CAFE) standards. This law mandated that the sales-weighted average fuel economy of a manufacturer's fleet of passenger cars must reach 27.5 MPG by the year 1985. To enforce this, the Environmental Protection Agency (EPA) was tasked with developing standardized laboratory testing protocols to measure fuel consumption, leading to the creation of the ubiquitous window sticker that has adorned every new car sold in the US since 1977. Over the decades, these testing protocols have evolved significantly to reflect real-world driving. In 2008, the EPA introduced stricter testing that accounted for cold temperatures, air conditioning use, and higher highway speeds. In 2010, anticipating the mass-market arrival of the Nissan Leaf and Chevrolet Volt, the EPA revolutionized fuel economy measurement again by introducing "MPGe" (Miles Per Gallon equivalent), creating a mathematical bridge that allowed consumers to directly compare the energy consumption of a gasoline engine with the electrical consumption of a battery-powered vehicle.

Key Concepts and Terminology

To accurately calculate and discuss vehicle efficiency, you must master a specific lexicon of automotive and mathematical terminology. Miles Per Gallon (MPG) is the standard imperial measurement of fuel economy, representing the number of miles a vehicle can travel on one US liquid gallon (which is exactly 3.78541 liters) of fuel. In contrast, Liters per 100 Kilometers (L/100km) is the metric standard used by the majority of the world; unlike MPG, where a higher number is better, L/100km is a measure of consumption, meaning a lower number indicates a more efficient vehicle. Odometer refers to the instrument in a vehicle that measures the total distance traveled over its entire lifetime, while the Trip Odometer (or trip meter) is a resettable sub-gauge used specifically to track the distance of a single journey or a single tank of fuel.

When discussing electric vehicles, the terminology shifts from liquid volume to electrical energy. A Kilowatt-hour (kWh) is a unit of energy equivalent to one kilowatt of power sustained for one hour; this is the standard "fuel" measurement for an EV battery. Miles Per Gallon Equivalent (MPGe) is a metric created by the EPA to compare EVs to gas cars; it is based on the scientific fact that one gallon of gasoline contains exactly 115,000 British Thermal Units (BTUs) of chemical energy, which mathematically translates to 33.7 kilowatt-hours of electrical energy. Therefore, an EV that travels 100 miles on 33.7 kWh of electricity is rated at 100 MPGe. Furthermore, you must understand Aerodynamic Drag, which is the fluid resistance of air pushing against the moving vehicle, and Rolling Resistance, which is the friction generated by the tires deforming against the pavement. Both of these physical forces are the primary enemies of fuel economy, requiring constant energy expenditure to overcome.

How It Works — Step by Step

Calculating accurate gas mileage and trip costs requires a precise, mathematical approach based on empirical data gathered at the fuel pump. The fundamental formula for calculating fuel economy is simple: Fuel Economy (MPG) = Total Distance Traveled ÷ Total Fuel Consumed. To calculate the financial cost of a specific trip, you use a secondary formula: Total Trip Cost = (Total Distance Traveled ÷ MPG) × Price Per Unit of Fuel. To execute this in the real world, you must use the "Full Tank Method." First, you fill your vehicle's gas tank until the pump's automatic shut-off clicks, and you immediately reset your dashboard trip odometer to zero. You then drive the vehicle normally for several days until the tank is mostly empty. When you return to the gas station, you fill the tank again until the automatic shut-off clicks. You then record two vital numbers: the exact number of miles on your trip odometer, and the exact number of gallons it took to refill the tank (found on the gas pump receipt).

Let us walk through a complete, realistic worked example of this calculation. Imagine you are driving a 2019 Toyota Camry. You fill the tank, reset the trip meter, and drive until the fuel light comes on. You return to the gas station, and your trip odometer reads exactly 412.5 miles. You pump gas until the nozzle clicks, and the receipt shows you purchased 14.2 gallons of fuel at a price of $3.45 per gallon. First, calculate the MPG: 412.5 miles ÷ 14.2 gallons = 29.04 MPG. You now know your vehicle is operating at 29.04 miles per gallon. Now, imagine you are planning a 1,250-mile road trip from Chicago to Denver, and you want to budget for gas. You assume the national average gas price is $3.60 per gallon. Using the second formula, you divide the trip distance by your known MPG: 1,250 miles ÷ 29.04 MPG = 43.04 gallons of fuel required. Finally, you multiply the required fuel by the price per gallon: 43.04 gallons × $3.60 = $154.94. By tracking your empirical data, you have precisely calculated that your one-way road trip will cost you exactly $154.94 in fuel.

The Rise of Electric Vehicles: MPGe and Cost Comparisons

The proliferation of Electric Vehicles (EVs) has fundamentally altered how we calculate transportation efficiency and travel costs. Because EVs do not consume combustible liquid, traditional MPG calculations are physically impossible. Instead, EV efficiency is measured in miles per kilowatt-hour (mi/kWh) or kilowatt-hours per 100 miles (kWh/100mi). To calculate the cost of driving an EV, the formula mirrors the traditional gas calculation: EV Trip Cost = (Total Distance ÷ Miles per kWh) × Cost per kWh. The cost per kWh is determined by your local utility company if charging at home, or by the charging network (like Tesla Superchargers or Electrify America) if charging on the road. Because electric motors convert over 85% of electrical energy into mechanical power—compared to internal combustion engines which waste nearly 80% of their energy as heat—EVs are vastly more efficient, but their cost advantages depend heavily on local electricity rates.

Let us perform a direct cost comparison between a gas vehicle and an EV using realistic numbers. Imagine Driver A owns a 2024 Honda Accord that averages 32 MPG. Driver B owns a 2024 Tesla Model 3 that averages 4.0 miles per kWh. Both drivers commute 15,000 miles per year. Driver A pays $3.50 per gallon of gasoline. To find Driver A's annual cost: 15,000 miles ÷ 32 MPG = 468.75 gallons of gas. 468.75 gallons × $3.50 = $1,640.62 per year. Driver B charges their EV entirely at home, where the utility rate is $0.16 per kWh. To find Driver B's annual cost: 15,000 miles ÷ 4.0 mi/kWh = 3,750 kWh of electricity required. 3,750 kWh × $0.16 = $600.00 per year. In this scenario, the EV saves the owner over $1,000 annually in "fuel" costs. However, if Driver B relied exclusively on public fast chargers that cost $0.48 per kWh, their annual cost would leap to $1,800.00, making the EV more expensive to fuel than the gas car. This mathematical reality underscores why calculating exact efficiency and unit costs is mandatory for modern vehicle owners.

Types, Variations, and Methods of Calculating Mileage

There are several distinct methods for calculating and tracking gas mileage, ranging from analog manual tracking to highly advanced digital telemetry. The most traditional and universally trusted approach is the Manual Pen-and-Paper Method (or its modern equivalent, a smartphone spreadsheet). This involves logging the odometer reading, gallons purchased, and price paid at every single fuel fill-up over the life of the vehicle. The primary advantage of this method is its absolute empirical accuracy; it tracks the exact volume of fuel entering the tank and the exact miles driven, natively accounting for variables like fuel evaporation or slight pump calibration errors. However, this method requires strict discipline, and missing a single receipt can corrupt a multi-tank average.

A more modern approach relies on On-Board Diagnostics (OBD-II) Integration. Since 1996, all cars sold in the US feature an OBD-II port under the dashboard. Drivers can plug bluetooth dongles into this port that communicate with smartphone apps. These devices read the exact fuel injector pulse widths and mass airflow sensor data directly from the engine's computer, calculating fuel consumption in real-time down to the milliliter. This method provides incredibly granular data, allowing drivers to see exactly how much fuel is consumed while idling at a red light versus accelerating up a hill. Finally, there is the Dashboard Display Method, commonly known in automotive circles as the "Guess-O-Meter." Modern cars display an average MPG on the instrument cluster. While highly convenient, this method is fundamentally flawed. Automakers program these algorithms to be optimistic, often overestimating actual fuel economy by 5% to 10%. The dashboard display relies on manifold pressure and injector timing rather than actual liquid volume, making it susceptible to calculation drift over time.

Real-World Examples and Applications

The practical application of gas mileage calculations extends far beyond casual curiosity; it is a vital tool for personal finance, commercial logistics, and major purchasing decisions. Consider a 35-year-old professional earning $85,000 a year who is deciding whether to accept a new job offer. The new job pays $5,000 more per year but increases their daily round-trip commute from 10 miles to 60 miles. By using a gas mileage calculator, they can determine the true value of the raise. Assuming they drive a truck getting 18 MPG and gas costs $3.80 per gallon, the new 60-mile commute (driven 250 days a year) totals 15,000 miles annually. 15,000 miles ÷ 18 MPG = 833.3 gallons. 833.3 gallons × $3.80 = $3,166 in annual commuting fuel costs. Compared to their previous 10-mile commute (which cost just $527 annually), the new job requires $2,639 in extra fuel. When factoring in taxes on the new salary and increased vehicle maintenance, the math reveals that the $5,000 "raise" actually results in a net financial loss, a realization only made possible by accurate mileage calculation.

In the commercial sector, independent contractors such as Uber drivers, DoorDash couriers, and Amazon Flex workers rely on precise mileage calculations for survival. The Internal Revenue Service (IRS) allows business owners to deduct a specific amount per driven mile from their taxable income (for example, 67 cents per mile in 2024). A delivery driver logging 30,000 miles a year can claim a $20,100 tax deduction. However, to maximize profit, the driver must calculate if their actual cost per mile (fuel, depreciation, insurance, and maintenance) is lower than the IRS rate. If a driver calculates that their heavy SUV costs them $0.75 per mile to operate (largely due to a dismal 14 MPG efficiency), they are mathematically losing money on every delivery they make, effectively subsidizing the gig economy platform with their own vehicle equity. Transitioning to a 50 MPG hybrid drops their fuel cost per mile from $0.25 to $0.07, instantly transforming their business from a loss to a sustainable profit.

Common Mistakes and Misconceptions

The realm of fuel economy is riddled with mathematical misunderstandings and behavioral errors that lead consumers to make poor financial decisions. The most profound and widespread misconception is The MPG Illusion. Human brains naturally assume that MPG scales linearly, meaning an increase from 10 to 20 MPG saves the same amount of gas as an increase from 30 to 40 MPG. This is mathematically false. Fuel consumption is an inverse curve. Consider a 10,000-mile driving year. Upgrading a heavy truck from 10 MPG to 20 MPG reduces annual fuel consumption from 1,000 gallons to 500 gallons—a massive savings of 500 gallons. However, upgrading a commuter car from 30 MPG to 40 MPG reduces consumption from 333 gallons to 250 gallons—a savings of only 83 gallons. Therefore, taking a gas-guzzler off the road does exponentially more for your wallet and the environment than upgrading an already efficient sedan to a hybrid.

Another incredibly common mistake is "topping off" the gas tank. Many drivers, attempting to get a perfectly accurate manual MPG calculation, will continue to squeeze the gas pump handle after the automatic shut-off clicks, trying to force fuel up the filler neck. This practice is extremely destructive. Modern vehicles are equipped with an Evaporative Emission Control System (EVAP), which includes a charcoal canister designed to capture gasoline vapors. Forcing liquid gasoline into the filler neck floods this charcoal canister with liquid rather than vapor, destroying the $500 emissions component and triggering a Check Engine Light. Furthermore, the excess fuel you pay for is often drawn back into the gas station's vapor recovery system, meaning you are paying for fuel that never actually enters your engine. To calculate mileage correctly and protect your vehicle, you must stop fueling the exact moment the pump clicks off the first time.

Best Practices and Expert Strategies for Maximizing Efficiency

Automotive engineers and professional hypermilers (drivers who use advanced techniques to exceed EPA fuel economy ratings) utilize a strict set of best practices to maximize the physical efficiency of their vehicles. The foundational strategy is rigorous Tire Pressure Maintenance. Tires naturally lose about 1 PSI (pound per square inch) of pressure per month, and for every 10-degree drop in ambient temperature, pressure drops another 1 PSI. Underinflated tires increase the contact patch and rolling resistance with the road. Experts recommend checking tire pressure monthly with a calibrated digital gauge and inflating tires to the exact specification listed on the driver's side door jamb placard (not the maximum pressure molded into the tire sidewall). Maintaining proper pressure can improve fuel economy by up to 3%, which translates to hundreds of dollars saved over the life of the tires.

Beyond maintenance, modifying driver behavior yields the highest statistical improvements in gas mileage. The most effective strategy is Predictive Braking and Acceleration. Internal combustion engines consume the most fuel when accelerating a heavy mass from a dead stop. Experts look a quarter-mile down the road; if a traffic light turns red, they immediately lift off the accelerator and allow the vehicle to coast, remaining in gear. Modern fuel-injected engines utilize a feature called Deceleration Fuel Cut-Off (DFCO). When you are coasting in gear without touching the accelerator, the engine's computer completely shuts off the fuel injectors; the engine continues to spin purely via the kinetic momentum of the wheels. During this coasting period, the vehicle is literally achieving infinite gas mileage. By minimizing complete stops and maintaining a steady, moderate speed—specifically staying below 65 MPH, as aerodynamic drag increases exponentially at higher speeds—drivers can routinely beat their vehicle's official EPA highway rating by 15% to 20%.

Edge Cases, Limitations, and Pitfalls

While gas mileage formulas are mathematically absolute, their real-world application is heavily influenced by environmental and situational edge cases that can drastically skew calculations. The most significant limitation is Weather and Temperature. In the winter, gas mileage plummets for several physical and chemical reasons. Cold air is denser than warm air, meaning the vehicle must push through a thicker atmosphere, increasing aerodynamic drag. Furthermore, engines take much longer to reach their optimal operating temperature (usually around 200°F). During this warm-up phase, the engine computer runs a "rich" fuel mixture—injecting excess gasoline to prevent stalling—which destroys fuel economy. Additionally, petroleum refineries switch to a "Winter Blend" of gasoline in colder months, which contains more volatile compounds like butane to aid in cold starting. This winter blend contains roughly 1.5% less energy per gallon than summer blend gasoline, guaranteeing a drop in MPG regardless of driving habits.

Terrain and elevation present another major pitfall for accurate calculations. A driver traversing the flat plains of Kansas will calculate a vastly different MPG than a driver navigating the steep inclines of the Colorado Rockies. When climbing a grade, the engine must fight gravity in addition to aerodynamic drag, requiring massive amounts of fuel. While some of this energy is recouped when coasting downhill, the thermodynamic losses in the engine mean the recovery is never 1:1. Finally, payload and aerodynamics fundamentally alter the baseline efficiency of a vehicle. Adding a roof rack or a cargo box destroys the aerodynamic teardrop shape of the vehicle, creating turbulent air that acts like a parachute. Driving at 70 MPH with an empty roof box can reduce fuel economy by up to 25%. Similarly, every 100 pounds of excess weight carried in the trunk reduces MPG by approximately 1%. When calculating fuel costs for a family road trip, using the vehicle's baseline unladen MPG will result in a severely underfunded travel budget.

Industry Standards and Benchmarks

To ensure fairness and consistency across a highly competitive global market, fuel economy is governed by strict industry standards and standardized testing protocols. In the United States, the ultimate authority is the Environmental Protection Agency (EPA), which operates the National Vehicles and Fuel Emissions Laboratory in Ann Arbor, Michigan. The EPA does not test cars by driving them on public roads; instead, vehicles are strapped to highly calibrated dynamometers (specialized treadmills for cars) in climate-controlled chambers. Professional drivers follow exact, second-by-second speed traces displayed on a monitor to simulate different driving conditions.

The EPA standard utilizes five distinct testing schedules to generate the numbers you see on a window sticker. The FTP-75 (Federal Test Procedure) simulates city driving, featuring frequent stops, idling, and an average speed of just 21.2 MPH over 11 miles. The HWFET (Highway Fuel Economy Test) simulates rural and interstate driving with no stops and an average speed of 48.3 MPH. Because automakers learned to optimize cars specifically for these gentle tests, the EPA introduced three supplemental tests in 2008: the US06 (high speed, aggressive acceleration up to 80 MPH), the SC03 (driving at 95°F with the air conditioning on maximum), and the Cold Temperature Test (driving at 20°F). The results of these five tests are mathematically blended to create the official "City," "Highway," and "Combined" MPG ratings. The "Combined" rating is an industry benchmark calculated as a weighted average: 55% City and 45% Highway. As of 2024, the CAFE standards mandate that the US fleet average must reach approximately 49 MPG by the year 2026, forcing automakers to rapidly adopt hybrid and electric technologies to meet these stringent federal benchmarks.

Environmental Impact and Emissions Calculations

Calculating gas mileage is not merely an exercise in financial accounting; it is the exact mathematical foundation for calculating a vehicle's environmental impact and greenhouse gas emissions. The combustion of fossil fuels is a chemical reaction that rearranges molecules, and the byproduct is carbon dioxide (CO2). A common misconception is that a gallon of gas, which weighs about 6.3 pounds, can only produce a few pounds of emissions. This ignores the chemistry of combustion. Gasoline is composed of carbon and hydrogen atoms. Inside the engine, each carbon atom bonds with two heavy oxygen atoms pulled from the outside atmosphere. Because of this added atmospheric oxygen, burning exactly one US gallon of E10 gasoline (gasoline blended with 10% ethanol, the standard at almost all US pumps) produces exactly 18.9 pounds of CO2. For pure, unblended gasoline, the number is 19.59 pounds of CO2. Diesel fuel, which is denser and contains more carbon per gallon, produces exactly 22.44 pounds of CO2 per gallon.

By understanding your precise fuel economy, you can calculate your exact carbon footprint. The formula is: (Total Annual Miles ÷ MPG) × Pounds of CO2 per Gallon. Let us look at a concrete example. A driver covers 12,000 miles a year in a Jeep Wrangler that averages 17 MPG. 12,000 miles ÷ 17 MPG = 705.88 gallons of pure gasoline consumed. 705.88 gallons × 19.59 lbs = 13,828 pounds of CO2 emitted into the atmosphere annually. If that same driver switched to a Toyota Prius averaging 52 MPG, their consumption drops to 230.76 gallons, producing only 4,520 pounds of CO2. By simply doing the math, the driver realizes that switching vehicles prevents over 9,300 pounds of greenhouse gases from entering the atmosphere every single year. For corporate fleets operating hundreds of vehicles, these emissions calculations are legally required for environmental, social, and governance (ESG) reporting and compliance with international carbon taxation laws.

Frequently Asked Questions

Why is my actual MPG consistently lower than the EPA sticker rating on my car's window? The EPA sticker represents a standardized laboratory baseline, not a guarantee of real-world performance. EPA tests are conducted on dynamometers in perfectly controlled environments using pure, ethanol-free gasoline, which contains more energy than the 10% ethanol blend sold at public pumps. Furthermore, real-world driving involves unpredictable variables that the EPA tests cannot perfectly replicate, such as aggressive acceleration, driving into heavy headwinds, navigating steep hills, and carrying heavy passengers or cargo. If your daily commute involves extensive stop-and-go traffic or speeds exceeding 75 MPH, your actual fuel economy will mathematically fall below the idealized laboratory average.

Does using premium gas (91 or 93 octane) improve my gas mileage? For the vast majority of vehicles on the road, using premium gas will not improve fuel economy by a single decimal point. Octane is not a measurement of energy content; it is a measurement of fuel's resistance to premature detonation (engine knock). If your vehicle's owner's manual states that regular 87 octane is "recommended" or "required," the engine is physically incapable of extracting any extra benefit from higher octane fuel. You are simply wasting 50 to 80 cents per gallon. However, if you drive a high-performance or turbocharged vehicle where premium fuel is strictly required, using regular gas will cause the engine's computer to retard the ignition timing to prevent damage, which will significantly reduce both horsepower and fuel economy.

How exactly does running the air conditioning impact my fuel economy? The air conditioning compressor in a traditional vehicle is a heavy mechanical pump driven directly by a rubber belt connected to the engine's crankshaft. Engaging the AC places a massive parasitic physical load on the engine, requiring it to burn more fuel just to keep spinning. According to automotive engineering data, running the AC on maximum in hot weather can reduce fuel economy by up to 25%, particularly at low city speeds where the engine is doing less work to move the car and more work to run the compressor. However, at highway speeds (above 60 MPH), rolling your windows down creates severe aerodynamic drag that requires more fuel to overcome than simply running the AC with the windows up.

Is it better for my gas mileage to let the car idle or turn the engine off and restart it? You should always turn the engine off if you are going to be stopped for more than 10 seconds. In the era of carbureted engines (prior to the 1990s), restarting a car required a rich dump of raw fuel, making idling more efficient. Modern fuel-injected engines are entirely controlled by precise computers and start in a fraction of a second using a microscopic amount of fuel. An idling modern engine consumes roughly zero miles per gallon, burning between 0.2 to 0.5 gallons of fuel per hour just to spin. This mathematical reality is why almost all modern vehicles are equipped with Automatic Start/Stop technology, which shuts the engine off at red lights to preserve fuel and reduce urban emissions.

How do hybrid vehicles achieve such incredibly high city MPG compared to highway MPG? Traditional gas vehicles get terrible city mileage because the engine wastes massive amounts of energy accelerating from a stop, and all kinetic energy is lost as heat through the brake pads when stopping. Hybrids reverse this physics problem using Regenerative Braking. When you press the brake pedal in a hybrid, the electric motor runs in reverse, acting as a generator. It converts the kinetic energy of the moving car back into electricity and stores it in the battery. When the light turns green, the hybrid uses that free, recovered electrical energy to accelerate the car up to 15 or 20 MPH before the gas engine even turns on. By eliminating the most fuel-intensive part of driving (accelerating from a dead stop), hybrids achieve spectacular city fuel economy.

Why do electric vehicles (EVs) lose so much range in cold winter weather? EV range loss in winter is driven by two distinct scientific factors: battery chemistry and cabin thermodynamics. First, lithium-ion batteries rely on liquid electrolytes to move ions between the anode and cathode. In freezing temperatures, this liquid becomes viscous, increasing internal resistance and temporarily locking away up to 15% of the battery's chemical capacity. Second, unlike a gas engine which generates massive amounts of waste heat that is piped into the cabin for free, an EV motor is highly efficient and generates very little heat. To keep the passengers warm, the EV must draw massive amounts of high-voltage electricity directly from the battery to power resistive electric heaters or heat pumps. Running the cabin heater can consume up to 30% of the vehicle's total battery capacity, drastically reducing the miles it can travel.