Document ID: chunk:federal_register_of_legislation:F2012C00283:reg:21:p34
Version: federal_register_of_legislation:F2012C00283
Segment Type: reg
Provision Reference: reg 21 (pt 34/39)
Character Range: 350742–353961

of body, the test shall be performed on the least aerodynamic body. The manufacturer shall provide the necessary data for the selection.
              4.1.2. Tyres
               The widest tyre shall be chosen. If there are more than three tyre sizes, the widest minus one shall be chosen.
              4.1.3. Testing mass
               The testing mass shall be the reference mass of the vehicle with the highest inertia range.
              4.1.4. Engine
               The test vehicle shall have the largest heat exchanger(s).
              4.1.5. Transmission
               A test shall be carried out with each type of the following transmission:
                Front-wheel drive,
                Rear-wheel drive,
                Full-time 4 x 4,
                Part-time 4 x 4,
                Automatic gearbox,
                Manual gearbox.
              4.2. Running-in
               The vehicle shall be in normal running order and adjustment after having been run-in for at least 3,000 km. The tyres shall be run-in at the same time as the vehicle or have a tread depth within 90 and 50 per cent of the initial tread depth.
              4.3. Verifications
               The following checks shall be made in accordance with the manufacturer's specifications for the use considered:
               Wheels, wheel trims, tyres (make, type, pressure), front axle geometry, brake adjustment (elimination of parasitic drag), lubrication of front and rear axles, adjustment of the suspension and vehicle level, etc.
              4.4. Preparation for the test
              4.4.1. The vehicle shall be loaded to its reference mass. The level of the vehicle shall be that obtained when the centre of gravity of the load is situated midway between the "R" points of the front outer seats and on a straight line passing through those points.
              4.4.2. In the case of road tests, the windows of the vehicle shall be closed. Any covers of air climatisation systems, headlamps, etc. shall be in the non-operating position.
              4.4.3. The vehicle shall be clean.
              4.4.4. Immediately prior to the test, the vehicle shall be brought to normal running temperature in an appropriate manner.
              5. Methods
              5.1. Energy variation during coast-down method
              5.1.1. On the road
              5.1.1.1. Test equipment and error
               Time shall be measured to an error lower than 0.1 s.
               Speed shall be measured to an error lower than 2 per cent.
              5.1.1.2. Test procedure
              5.1.1.2.1. Accelerate the vehicle to a speed 10 km/h greater than the chosen test speed V.
              5.1.1.2.2. Place the gearbox in "neutral" position.
              5.1.1.2.3. Measure the time taken (t1) for the vehicle to decelerate from speed
               V2 = V + ΔV   km/h   to   V1 = V - ΔV   km/h
              5.1.1.2.4. Perform the same test in the opposite direction: t2.
              5.1.1.2.5. Take the average T of the two times t1 and t2.
              5.1.1.2.6. Repeat these tests several times such that the statistical accuracy (p) of the average

           is not more than 2 per cent (p ≤ 2 per