EPA Fuel Economy Ratings

  Fuel Economy Ratings
(for the Environmental Conservation Agency)
EPA Fuel Economy Ratings The
 
Importance of Fuel Economy :
 
There are many important points that make fuel economy so important, including, but not limited to, the following points:
Saving money:
A person can save between 300 to 500 dollars annually by choosing the car that suits his needs and is more efficient. These amounts may reach thousands of dollars with the service life of the vehicle. Fuel-efficient car models come in all shapes and sizes, and one doesn’t have to sacrifice size or requirements to get a high-efficiency car.
A person can also increase the fuel economy of his current vehicle by complying with proper driving style and keeping the vehicle in good running condition.
Supporting the country’s economy: the
greater the fuel economy, the more energy savings this leads to. In the United States, for example, importing fuel costs $3 billion a week.
 Environmental protection:
Burning fossil fuels such as gasoline or diesel contributes to many environmental problems, such as air pollution, so-called smog and global climate change. In addition to what may result from fuel leakage accidents during the transportation process, which leads to the destruction of nature and pollution of groundwater and water sources.
Saving energy sources:
Most of the cars and trucks we drive today are powered by petroleum-based fuels. Petroleum is a source of non-renewable energy, and discussions are now taking place for how long this source of energy will last, and often we will find another source of energy to drive cars on time. But until there is another source of energy available, it is smart to use oil more efficiently so that there is a time period in which we continue using oil until an alternative source is provided and so that the transition period is not more painful and more expensive.
 
Determination of fuel economy rates:
 
Federal law requires auto manufacturers to determine the fuel economy of new cars sold in the United States. This information given regarding fuel economy is written on a paper that is attached to the car window glass to help the consumer make a decision based on fuel economy when he buys a new car. These stickers may differ in form but must have the same information.
 
 

 
 
Why is the fuel economy value (lower in most cases) for some cars different from the dealership estimate?

Many factors influence the different fuel economy values ​​of the customer’s vehicle in relation to the agency’s discretion. These factors may be as follows:
o Driver style and driving condition
o Vehicle condition and maintenance
o Fuel
difference o Vehicle interior differences
o Ignition period (new engine)
Driver style method and driving condition
Rapid acceleration and strong braking reduce fuel economy by 33% on highways and 5% in the city. Agency tests don’t take that aggressive route into account.
Increased empty load time reduces fuel economy. Although the agency’s in-city tests take into account the state of the empty load, drivers who increase the time of the empty load feel less fuel economy.
Driving at high speed increases air resistance and reduces fuel economy. The agency’s tests take air resistance into account at highway speeds but up to 60 mph (100 km/h), but the driver often exceeds that speed.
Cold weather and short driving distances can lead to reduced fuel economy, as the car’s engine does not operate efficiently until it reaches operating temperature. In cold weather, it takes longer for the car to reach its operating temperature, and in short distances, the car works for a short time at operating temperature. Note: Running the car without a load for a long time does not improve fuel economy, but it uses more fuel and leads to higher pollution.
The upper grille and the load above the vehicle can increase air resistance and reduce fuel economy. The vehicle in agency tests is not tested with additional external payload.
Towing a trailer or overloading a vehicle can reduce fuel economy. The vehicle is estimated to carry 300 pounds (135 kilograms) of passengers and luggage when tested.
Operation of electrical accessories (eg adaptation) reduces fuel economy. Operating the air conditioner at maximum setting reduces fuel economy (miles/gallon) by an approximate 5-25% compared to the non-operating state.
Driving in a mountainous area or on unpaved roads can reduce fuel economy. In dealership tests, the vehicle is assumed to operate on a level road.
Using four-wheel drive reduces fuel economy. Four-wheel drive vehicles are tested in a 2-wheel drive condition. The use of four wheels for propulsion causes the engine to operate with more power, which increases the friction loss.
Condition and maintenance of the vehicle:
A tuned engine burns less fuel, and of course the fuel economy will suffer if the engine is not tuned. Failure to adjust tire angles or incorrect inflation reduces fuel economy, as in the case of a clogged air cleaner or loaded brakes.
Difference in the amount of energy in fuel:
Some fuels contain less energy than other fuels. Modified fuel use may increase fuel economy by 1-3%. The energy content of the fuel may differ for the seasons. The fuel sold in the summer may contain 1.7% more energy than the winter fuel.
Car Interior Differences:
Some small car differences in the way the car is made or assembled can lead to a difference in fuel economy for the same car and model. These differences are often small, but some drivers may feel a difference from the fuel economy estimated by the agency.
Engine lubrication period:
New cars to reach the optimum economy, until the engine finishes from the period of lubrication. This may take 3-5 thousand miles (5-9 thousand km).
Fuel economy ratings for different cars from drivers who own the same car Shared MPG EstimatesHow to Test Vehicles to Determine Fuel
Economy Ratings Fuel economy is measured under controlled conditions in a laboratory using standard test steps specified by federal law. The cars are tested by the manufacturer – often a pre-production model of the car – and the results are given to the Environmental Protection Agency (EPA). The agency sees the results, and about 10-15% is confirmed by testing them in the agency’s laboratory. National Vehicles and Fuel Emissions Laboratory.
In the agency’s lab, the steering wheels are placed on the cylindrical wheels of a machine called a dynamometer that simulates a driving situation — similar to a stationary sports bike. The energy required to move these drums can be tuned to represent the condition of the air force and the vehicle’s weight (air resistance and rolling resistance). A professional driver drives the vehicle through a schedule, which simulates a specific journey within the city or on a highway.

Each revolution is defined by the speed of the car that it must travel during each second. Li (rubber tube) is connected to the exhaust pipe to collect the exhaust gases, from the amount of carbon in the exhaust the amount of fuel used during the test is determined. This method is more accurate than using a fuel gauge.
Adjusting the average fuel economy rating from the test:
In the 1980s, the agency found through a study that drivers were getting lower than the agency’s estimated fuel economy ratings through lab measurements. As a result, I asked that city and highway fuel economy labels adjust readings by less than 10% for city driving rates and 22% for highway driving rates to give more realistic values ​​for real-life driver values.
Fuel Economy Test Courses
The Agency’s fuel economy test consists of two driving cycles (routines, schedules) that take place in the laboratory.
City driving: In this test, the car starts with a cold engine and follows a similar stop-and-go driving style (rush hour driving). The test cycle consists of rotating the engine on an empty load (the car stops with the engine running) and the average speed of the car during the test is 20 mph (32 km/h).
Highway driving: the engine is at operating temperature, long travel distances without traffic jams. The average test speed is 48 mph (65 km/h) and the test does not include stops during testing or running on an empty load.

The city schedule represents low-speed driving in stop-and-go traffic and considerable idling.   City driving is slow speed, traffic with lots of stops and starts, and lots of running on empty load The highway schedule simulates non-metropolitan driving at higher speeds, with no stops and negligible idling.  Driving on highways is high speed traffic with no stopping or cold running test cycleDriving Cycle FeaturesHighwaysinside the cityConstant traffic on the highwayLow speed with stop and moveTrip typeDistance 10 miles, 16 kmDistance 11 miles, 17.7 kmTest distanceTime 12.5 minutesTime 31 minutesTest timeSpeed ​​48 mph, 77.2 km/hSpeed ​​20 mph, 32.2 km/haverage speedSpeed ​​60 mph, 96.5 km/hSpeed ​​56 mph, 90.1 km/hmaximum speedThere is no stopping23number of stopsThere is no operation without load18% of the test timeOperating time without loadEngine at operating temperaturecool engineEngine temperature at start-upTemperature 68-86 Fahrenheit, 20-30 Celsiuslaboratory temperatureOff modecar air conditioner