Thread: MPG Real MPG (1.8)
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Old 13th June 2007, 09:45   #18 (permalink)
Pottsy
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Quote:
Originally Posted by terry View Post
Is all of the test on a rolling road?
Also I think the manufacturers also have a few tricks, like over inflating the tyres to reduce rolling resistance, and removing unecessary things to reduce weight (although perhaps that is why there is no spare wheel or rear wiper!).

Terry
Yes all on a rolling road.

Tyres and weight are all covered in a long spec. The car is driven by a robot on a rolling road which is calibrated to reflect the effect of weight and other losses. It's all very complicated, but the figures are designed to be relative, not absolute (since no two drivers drive the same way).

5.3. Tyres
The tyres must be of one of the types specified as original equipment by the vehicle manufacturer, inflated to the pressure recommended for the test load and speeds (adjusted, where necessary, for test-bed operation under test conditions). The pressures used must be indicated in the test report.


6.2.1. Reference mass
Mass of the vehicle in running order less the uniform mass of the driver of 75 kg and increased by a uniform mass of 100 kg.

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