Mark Chung (c) and racers Alex Job and Paul Ritchie pose with the ADVAN ENV-R1 racing tire--predecessor of the dB Super E-spec passenger tire.
An observant reader questioned whether that more fuel-efficient design at all impacted braking performance. We answered that in general it does, but that we'd forward the question to Yokohama engineers for their official answer regarding the Super Nano Power Rubber dB Super E-spec tire in particular.
Following is what Yokohama's Mark Chung had to say:
"Your readerís astute speculation about the compromise between lower rolling resistance coefficient (RRC) and overall tire grip makes perfect sense if we assume using conventional tire compounding and building methods. The unique feature about the dB Super E-spec is that its compound addresses the mentioned compromise by utilizing the interaction between natural rubber and orange oil. Specifically, this compound, which we call the dual-mode compound, maintains its low RRC mode when in straight-line, non-cornering, non-braking situations. But when the tire is placed under load, whether braking or cornering, it quickly generates heat and the compoundís characteristics change to deliver the grip necessary to negate any compromise I mentioned earlier. When the tire returns to straight-line mode, its characteristics change back to the low RRC mode. It is like having a switch to turn on/off the tireís behavior, except that the tire takes care of the switching itself! This dual-mode behavior is activated by orange oil. Orange you glad your reader asked this question?"
Guess that answers that, and if we must say so, it's a very clever manipulation of chemistry and physics on the part of Yokohama's engineers.