Phoenix, Arizona – The more I learn about tires, the more I realize that there’s a heck of a lot to know about them. And then I wonder why tire education isn’t mandatory for everyone who gets behind the wheel.
Bridgestone flew us to the arid and sun-drenched state of Arizona to teach us some facts about a new trio of tires, whose only similarities is that they’re all round and black.
One will help you save money on fuel, another may ensure that you’re never stranded with a flat by the side of the highway – and one was actually developed in conjunction with the only car on which it’s available.
We spent the day at the Wild Horse Motorsport Park (formerly Firehawk) to see for ourselves if the new products lived up to their claims.
Ecopia EP422 Plus
Ecopia, Bridgestone’s “low-rolling-resistance” fuel-saver tire was launched in 2009 in answer to our increasing awareness of conservation, and to help vehicles comply with upcoming CAFE (Corporate Average Fuel Economy) regulations.
A vehicle that has to work harder to overcome inertia, or resistance to moving, consumes more fuel. Low-rolling-resistance tires are designed to initiate movement with less energy by virtue of their lightweight construction using thinner sidewalls and generally shallower tread depth.
Low-rolling-resistance tires can improve your fuel economy by as much as four percent, depending on road surface and weather conditions. That may not sound like much, but could save you hundreds at the pumps each year – almost enough to pay for the tires.
The problem with low-rolling-resistance tires is that they have always tended to be a compromise; the money saved in fuel comes at the cost of decreased performance. Shallower treads, more flexible sidewalls and different composites generally resulted in poor performance and less grip. They wore out faster too, which pretty much cancelled out any fuel savings.
Ecopia tires consist of Bridgestone’s patented NanoPro-Tech compound. This process binds the ingredients (silica, carbon and polymers) in a more evenly distributed blend for better handling consistency. It’s then molded into an all-season tread design using notched shoulders for better cornering and independent centre blocks for improved dry grip. “Fuel-saver sidewalls” help return energy to the tire, and generate less heat. Bridgestone claims they do this by quickly regaining their original shape, a process called hysteresis. Circumferential grooves channel water away for better grip on wet roads and help prevent hydroplaning, while the consistent use of silica helps improve traction by increasing the tire’s flexibility.
Its latest iteration, the EP 422 Plus, reportedly returns a 35 percent improvement in fuel reduction over the previous Ecopia.
To illustrate the gains in performance, we drove a loopy slalom course, part of which was under approximately an inch of water. In identical Toyota Camrys – one of which wore the previous generation Ecopia tire, the other EP 422 Plus – we could clearly see a marked improvement in grip, particularly on the wet pavement. Both tires proved capable, but the newer Ecopia was the clear winner in the hairpin, enabling us to stop and turn quicker than the old tire, which gave way to understeer when pushed.
Available now in 43 different sizes, the EP422 fits 80 percent of the coupes, wagons and sedans currently on sale. It comes with a 70,000-mile tread wear warranty.