❌ About FreshRSS
There are new available articles, click to refresh the page.
Before yesterdayHyundai Fuel

Coastdown Facts

Coastdown Facts


A coastdown test is a procedure that determines key metrics used to calculate a vehicle’s fuel consumption values or “L/100kms rating.”   The litres per 100kms ratings are established using a machine called a “dynamometer.”   A dynamometer is like a treadmill for vehicles, enabling vehicles to be operated indoors on a stationary platform to simulate real-world vehicle operation.  The level of resistance on the dynamometer is adjusted for each specific vehicle model tested to simulate the level of resistance that the vehicle would encounter if operated outside on the road.   Coastdown testing is used to determine the appropriate resistance levels (or “road loads”) to use on the dynamometer for a given vehicle model.  Coastdown testing is used to measure all types of resistance encountered by a given vehicle model during real-world operation, including:

  • Vehicle aerodynamic resistance, a factor affected by the vehicle’s shape, which determines how much air the vehicle has to push out of the way as it moves. The more resistance, the more energy has to be expended.
  • Tire rolling resistance, a factor related to tire design that determines how much energy the vehicle has to use to overcome the resistance caused by the interface between the tires and the road.
  • Driveline and powertrain mechanical resistance, a factor of the vehicle’s drivetrain and how much energy the vehicle has to use to overcome internal friction to drive the wheels.

Coastdown Method

  • A vehicle that has been properly broken in prior to the test (generally the mileage, fluids and fuel, tires and vehicle warm-up) is driven up to a certain speed, typically around 128 KPH, after which it is put into neutral  and allowed to coast until its speed drops below 14 KPH.
  • Special devices in the vehicle accurately measure environmental conditions (ambient temperature, humidity and barometric pressure), performance data, and speed and distance traveled during the vehicle’s deceleration.
  • In order to eliminate the effect of wind speed and direction, the test is performed multiple times (a minimum of 5 runs) on a completely flat, straight and dry road in both directions of the track.  Analysis of the recorded speed and distance information provides the vehicle’s road load force.


  • A dynamometer is an electric motor that is connected to the vehicle and simulates standard highway and city driving cycles, enabling generation of simulated fuel consumption and emission values. 
  • EPA and NRCan publish fuel consumption results, which are a by-product of emissions testing.
  • Manufacturers began to reduce road load in response to public demand for more fuel efficient vehicles.
  • The coastdown test is the standard industry technique to determine vehicle road load, which coupled with dynamometer testing, enables the manufacturer, the EPA and NRCan to measure fuel consumption and emission values. 
  • The Society of Automotive Engineers (SAE) developed a standard procedure (J2263- Dec 2008) to perform road load measurement using coast down testing.
  • The Society of Automotive Engineers (SAE) developed a standard procedure (J1263- Mar 2010) to perform road load measurement and dynamometer simulation using coast down testing.


  • The current government-approved standard for road load measurement using onboard anemometry and coastdown testing techniques is SAE International Standard J2263, which was most recently updated in 2008. 
  • November 15th 2012 at 15:27

Hyundai/Kia Consumption Background


Fuel consumption is measured under controlled conditions in a laboratory, using a device called a dynamometer.  The dynamometer simulates a vehicle driving on the road.  Fuel consumption is measured by determining how much of certain gases are emitted from the vehicle during the test cycle.  Emissions are measured to determine how much fuel is burned and then converted into litres per 100kms for the fuel consumption label.  The same measurements are now used for purposes of the Environmental Protection Agency’s and Environment Canada’s greenhouse gas program.

Manufacturer Testing
All manufacturers test prototype vehicles, calculate the fuel consumption information and submit the data to the EPA for review.  EPA issues Certificates of Conformity based on the data submitted by manufacturers.  Environment Canada accepts EPA Certificates of Conformity as evidence the vehicle meets Canadian emissions regulations.  Confirmatory tests are run on a percentage of production vehicles.  There are typically variances between the prototype test information originally submitted to EPA and Environment Canada and the later production tests. 

Coastdown Testing
In order to measure and calculate fuel consumption, a manufacturer must first assess each vehicle’s “coastdown” value.  This value is determined through a series of tests run by the manufacturer.  The EPA informed Hyundai and Kia’s technical center that it had questions about how Hyundai and Kia had determined the coastdown values for its vehicles.  EPA’s independent testing had resulted in coastdown values different than those reported by Hyundai and Kia.

Hyundai/Kia Cooperative Test Program with EPA
The companies engaged in a testing program with EPA to determine the source of the test result differences.  The companies’ technical team found certain discrepancies in the way in which the coastdown testing was conducted.  EPA also found that the companies’ interpretation of certain aspects of the procedures differed from EPA’s understanding of how the tests are generally conducted.  

Hyundai/Kia Future Testing
Hyundai and Kia have agreed to conduct all future testing in the manner EPA has communicated to the companies and to rectify certain procedural errors found during the test program.  The procedural errors relate primarily to how the companies’ testing engineers identified vehicle weight and chose test runs for calculation of the coastdown values.  Hyundai and Kia are committed to working with EPA to ensure that all future testing meets EPA’s expectations.

  • November 2nd 2012 at 22:39

Fuel Consumption Ratings Background


Fuel Consumption Ratings
Fuel consumption is measured under controlled conditions in a laboratory, using a set of tests that are set forth in regulations issued by the U.S. Environmental Protection Agency (EPA) and adopted by Natural Resources Canada (NRCan).  The test results are used for two purposes:  (1) to establish compliance with the greenhouse gas emissions regulations; and (2) to provide the estimated fuel economy rating for each vehicle.  These ratings are applied to fuel consumption labels normally found on showroom new vehicle windows and are published on the Canadian government-sponsored website:

Fuel Consumption Labels and Real World Performance
Both EPA and NRCan websites advise that while its ratings are a useful tool for comparing the fuel economies of different vehicles, fuel consumption ratings are not fixed numbers.  According to NRCan, “…no test can simulate all the possible combinations of climate road conditions, vehicle load and driving habits. As such, your vehicle’s fuel consumption may differ from the estimates…”  EPA and NRCan have identified several factors that can lower a car’s fuel consumption including:  cold weather, aggressive driving, excessive idling, accelerating, and braking in stop-and-go traffic, driving with a heavy load or with the air conditioner on, improperly tuned engine or under-inflated tires; use of remote starters, and small manufacturing variations.

More information on fuel consumption labels and real world performance can be found here:

  • November 2nd 2012 at 22:36

Hyundai Fuel Consumption Reimbursement Program Facts


Hyundai is committed to fully reimbursing affected current and former vehicle owners for the difference in fuel costs associated with our rating change.  Our top priority is to make things right for Hyundai owners.

Program Mechanics

Claim Process

  • Current owners (purchased/leased new or pre -owned):  Current owners must log onto the Customer Reimbursement website ( and enter the Vehicle Identification Number (VIN) to determine if the vehicle is included in the program.  If included, enter the current owner’s name and a message will display if customer matches Hyundai Auto Canada’s information as the current owner and they will be directed to visit their Hyundai dealership to submit the reimbursement claim. If the owner’s name entered does not match the owner’s name on file, the customer will be directed to the dealership and required to provide a proof of ownership. 
  • Former owners (purchased/leased new or pre -owned): Former owners must log onto the Customer Reimbursement website ( and enter the VIN to determine if the vehicle is included in the program. If included, former owners must visit their Hyundai dealership and provide proof of mileage during their ownership of the vehicle (e.g., purchase and sale documents, emissions certificates, repair orders or other documents demonstrating mileage) to initiate the reimbursement process.
  • Once their claim has been approved, owners will be sent a prepaid credit card with their reimbursement. 


  • Reimbursement formula:  Owners will be reimbursed based on:  (1) 2012 average fuel prices for their geographic area, plus 15%; (2) kilometers accrued by the owner; (3) change in combined (city/hwy) fuel consumption estimates for their vehicle; and (4) fuel grade (regular or premium) recommended for their vehicle.
  • 2012 average fuel prices will be based on The Kent Group data for the owner’s geographic area (Four regions in Canada: Atlantic, Quebec, Ontario and Western Canada).  The Kent Group is an independent company contracted by NRCan, who provides the fuel pricing data used on NRCan’s Fuel Focus Website. The Kent Group website is:
  • Owners will receive a prepaid credit card with the reimbursement amount based on the above formula.

Applicable Time Period Limitations

  • Current and former owners may make a claim for fuel consumption reimbursement beginning November 2, 2012.  Owners must register and make a claim before December 31, 2013. 
  • Current owners are advised to make one claim every calendar year, although they are permitted to make more than one claim per year.  They may also submit a second claim in a calendar year upon the sale of their subject vehicle.  Former owners may make one claim (per vehicle).
  • Fuel Consumption reimbursement will not be eligible for new owners taking ownership of any of the affected vehicles after November 2, 2012 excepting inter-family changes of ownership between immediate family members.

HACC Processing:  Hyundai will review owner requests and send reimbursement within 30 days of their complete claim submission.

  • November 2nd 2012 at 22:36