This could very well be true. If the low rolling resistance factors are based on the tread then when that trad wears out the tire will be equal to a non-LRR tire. If the LRR factors are mostly in the sidewall and plies then the tire will still be better than a non-LRR tire even after tread is worn. FWIW I am testing a set of Energy Saver A/S right now and they appear to be approx. 3mpg better than my LRR AVID Ascend tires which! The Ascends are almost identical to the OEM AVID S33D tires.