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Old 02-21-2010, 03:48 PM   #66 (permalink)
orange4boy
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The Golden Egg - '93 Toyota Previa DX
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Some interesting comments on efficient tire tread design from:Fuel efficiency: new tread design factors.

Quote:
Q. What steer, drive and trailer tread design factors areaimed at improving vehicle fuel efficiency?

Graves: Much of the rolling resistance of a tire, about 35%to 50%, comes from the tire tread, so its design can have a significant impacton fuel economy. Typically, shallow treads are more fuel-efficient than deepones and rib designs tend to be more fuel-efficient than lug or block designs.But there are exceptions to the rib versus lug rule. With newer-generationdrive tires, incorporating continuous shoulder ribs, tire designers have foundthey can be a lot more flexible in selecting tread rubber compounds. The resultis that certain closed-shoulder drive tires offer overall fuel economy equal toor even better than some rib designs.

Miller: Fuel-efficient steer, drive and trailer tires haveunique tread designs and patterns. In particular, a fuel-efficient drive tire’stread is more rib-like than the tread on a standard tire, and while it may lookless aggressive it does not necessarily have less traction as many driversbelieve.

Willis: When designing a tread pattern for fuel efficiencyit is important to concentrate on reducing the deflection of the patternelements and the volume of the deflected rubber. This can be achieved in avariety of ways that include reducing the pattern depth and increasing thepattern stiffness. In addition, a base compound that is optimized for goodrolling resistance gives designers some degree of freedom when designing thetread pattern.

Baldwin: Tread designs with less movement in the featuresare better for fuel efficiency. Therefore, designs that use solid shoulders andare more “rib-like” are the most efficient. Block and siped designs tend to beless efficient, but to minimize this effect, sipes that are zigzagged in twodirections can allow for good traction while locking the block in place.
Possibly why the Nokian H can be such a good performer and still have low RR. Rib like...
Quote:
Nokian H wins the German ACE tyre test: "Well-deserved test winner is the Nokian H" writes "ACE Lenkrad" as result of its latest summer tyre test.
I'm pretty sure I'm getting a set of these this spring.
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