R377

They used to use a lot more silica compounds versus rubber compounds in low rolling resistance tires (not sure if they still do that). I recall one of the problems was a static charge build up in the car, so much so that sometimes tollbooth attendants would get a pretty good shock when the driver handed him change and made contact.

Big Als Z

Low rolling resistance means less surface area on the tire, less sipping, lighter tires as well. The Prius uses the Goodyear Integrity, as does the Toyota Corolla. They are a lower speed rating, usually a S rated tire, and have a very tight tread pattern. Like someone said, you sacrafice traction and handling for improved rolling resistance.

A BF Goodrich All Terrain KO would be the anti low rolling resistance tire. GM works with tire manufactures to create certain tires specificily for thier cars. If you see on any GM car the letters "TPC", that indicates that its an original GM tire or a tire codesigned by GM and that tire maker for a specific car.

muckz

I guess they could be putting these straight from the factory:

muckz

This got me thinking, many of us replace tires on the vehicles we buy, and I'm wondering if that contributes to not getting the advertised mileage... Imagine, if the difference is 5%, highway mileage can drop from 30 mpg to 28.5 or possibly even less with really sticky rubber.

Plague

Sounds like you also changed wheels.

JeremyNYR

The size and shape of tread blocks and how you transition from one block to another as the tire rotates may also affect rolling resistance. The two you listed are a good contrast. The Comp TAs have small separated tread blocks whereas the F1s have treads that are thin and long, which wrap around the tire radially. The smooth transitions from one tread block to another make the tire quieter and I'm thinking that they would also reduce rolling resistance. Now I'm interested to look at the tread patterns of some of these new tires going on the 2009 models

Tokuzumi

Which explains why most toll booth attendants basically throw the change at you.

bossco

They (Michelin) still do, sillica has other benefits besides low rolling resistance, they had a lock on that for a long time, but I believe Bridgestone uses sillica as well.