* In SAE Paper 780613, they found that 'ICE' vehicles could see up to a 67% mpg variability between 20F and 100F on short 'cold-start' trips, in which the cars never achieve thermal- equilibrium temps for their respective ambient temperatures.
* Tire losses are part of this calculus.
*As mentioned, the SAE considers 70F 'COLD.'
*And R-R can be 40% greater 'cold', compared to when fully up to thermally-equilibrated temperature ( CAR and DRIVER, page-72, August, 1979 ).
* Also, the lower the ambient temperature, the greater the time/distance necessary to achieve equilibrated temperature is required.
*Rubber hysteresis values for both sidewall and tread-block surface are directly impacted by temperature.
* It's no mystery why pre-green- flag race cars are seen racking their front wheels to 'scrub' as much heat into them before the flag drops. It aids both coefficient of friction ( traction ) and lower rolling-resistance ( coefficient of power absorption ).
