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One of the ways that auto makers are trying to squeeze a few more miles per gallon into their vehicles are with improvements to tires. But tire makers have long been constrained by a principle that says any improvement to rolling resistance (the ability for tires to overcome the resistance they face as they roll over the road) would lead to lower tire durability and lower ability to grip the road in wet conditions.
Some companies are putting that principle to rest, or at least tweaking it a bit, by increasing rolling resistance along with bettering or not harming the other parts of what is called the “magic triangle of tire technology,” as detailed by Chemical & Engineering News.
Overcoming the resistance that tires encounter when they roll accounts for 20% of the fuel used in the average car, according to the French tire manufacturer Michelin. By itself, rolling resistance is responsible for a startling 4% of worldwide carbon dioxide emissions from fossil fuels, Michelin says.
So auto makers have a clear incentive to push tire companies to come up with products that have better rolling resistance. Michelin developed a tire in 1992 that had a rolling resistance up to 30 percent less than other tires by switching out a material in tire treads.
Michelin's latest entrant in the greener tire market is its Energy Saver A/S, boasting 8 percent higher fuel efficiency than other tires like it as well as better performance when braking on wet roads.
Goodyear Tire & Rubber's Assurance Fuel Max tire claims to provide 4 percent better fuel efficiency than previous Assurance tires, but with the same wear and traction properties.
Lanxess, a rubber company, is delving into new territory with Nanoprene, a material made of nanomaterials and completely new to tire treads.
The company says Nanoprene improves the abrasion resistance, grip, and rolling resistance of tires, pushing out all three corners of the magic triangle simultaneously. Lanxess recently began commercial production of the material. Its first customer, Toyo Tire & Rubber, will use it in winter tires.
But in the end, all of the chemical and tire innovations can be moot if tires are not inflated properly, which is why Exxon-Mobil Chemical is creating materials that make tires hold air better.
Tires - http://www.flickr.com/photos/dailyinvention/ / CC BY 2.0
Climate
Greener or more toxic?
It is heartening to hear that tire manufacturers are making performance improvements that may reduce the energy requirements of tires, but does that make them green? Not unless we know what chemistry is going into those supertires. Tire already include a toxic soup of carcinogens, reproductive toxicants and other nasty chemicals that get readily disbursed into the environment through high speed road wear. To add more chemicals - or worse untested nanomaterials - to this soup may only be trading evils.
One more reason we need to apply radical transparency to product selection so we can fairly evaluate the trade offs.
Of course ultimately the only green tires is one on a mass transit vehicle.
Did you mean to say lowering rolling resistance?
"by increasing rolling resistance along with bettering or not harming the other parts of what is called the 'magic triangle...'
As the end of the article states, Inflation Air Pressure is probably the main cause of poor vehicle mileage. My own 2 hybrid vehicles with real-time MPG feedback, bear this wisdom out in real life. I air the tires up, I get 7-8 mpg better instantly.
Hmm, the Nanoprene invention sounds like it could be a problem in the environment as tires made of this material will also wear down, releasing ecologically questionable nanomaterials in the form of tiny rubber particles onto roadways where it will wash into rivers and/or be sucked into other vehicles in traffic, polluting the air which human passengers are breathing. This stuff likely won't biologically break down in the environment... and spreading it into the ecosystem is not going to be a good idea. How would you like to be a fish with nano-materials stuck in your gills? It will be like a micro version of the mid-pacific gyre of floating plastic. See Algalita Marine Research Foundation for more info on that one...
How many millions of tons of tire rubber are dispersed on US roadways and environment each year? I know there's tons of lead from tire weights too. I am glad new car makers and European users have phased out lead tire weights, and can't weight (ha ha) for the US to follow suit. For the same basic reason, the weights fall off and are ground to bits on area roadways, polluting water, soil and air with toxic lead.