Monday, November 12, 2007

Environmental Impact of Larger-Diameter Car Tires

A recent trend I see that makes me even more conscious of our race to destroy the planet is this push towards large diameter car wheels and tires. Did you know that, counter-intuitively, a larger-diameter tire that has more surface area to wear down, actually nearly always wears more quickly than a smaller diameter tire?

Just go to a car dealer and ask them how many miles to expect out of those bigger and fancier 18" tires, and then ask the same question as applied to the same model car but with smaller (less "premium" / "sporty") tires. Or, go to a place like Tire Rack dotcom (which I highly recommend for great deals on tires), and just check out the wear ratings on the various size tires. I can pretty much guarantee the smaller tire is going to last longer. And, to top it off, the smaller tires are cheaper (conversely, the larger tires that are going to wear faster are more expensive)

So, not only do the larger tires wear faster, but the also cost more - talk about a double whammy to the pocket book! I recently saw a new 2008 Honda Accord Coupe in its "top of the line" configuration, which sported snazzy 18" low-profile sporty 235/45VR18 tires. I asked how many miles to expect out of a set -- "about 20,000" I was told. Eeek! Only 20K miles! Wow, what happened to the days where a Honda Accord was a family car that sported 15" tires capable of 50,000 miles between changes? And, these new 18-inch Michelin Pilot HX MXM4's are going to set you back at least $255 each (that's the discount Tire Rack Price too)! (read: over $1,000 just for a set of new tires that you may be putting on your car once ever year or two with "normal"-mileage driving habits).

Sure, like anyone with a sense for visual appeal, I can appreciate how fantastic these large wheels and tires look on something as sharp as the new 2008 Honda Accord Coupe, but what I can't understand is who wants to spend this much money on their tires regularly. And, I have yet to get to the environmental-impact side of the equation. Honda sells this car as something like a near-zero-emissions vehicle. Well, perhaps so (with regards to what comes out of the tailpipe), but what about all that (quickly) spent rubber that ends up polluting the environment? Oh, and "rubber" tires require a lot of OIL in their production. But, what's a little more oil consumption these days as oil reaches a record $100/barrel?

By the way, I don't want to seem like I'm picking on just Honda here. Fact is, after this little Honda experience, I went shopping around to see what all the various new cars sported for tires these days. Over and over, regardless of automobile brand, I was confronted with "base" models that had at least 16" tires on them, and quite often larger (even a little Scion Tc has 17" wheels by default now!). When asked why all the wheel options (which, never include downsizing, but nearly always include upsizing) are the way they are, some dealers say it is "customer demand", but others indicated that they believe tire manufactures have essentially worked deals with the car companies to push these larger, quicker-wearing, more expensive tires (gee, I wonder why!?).

If you are under 25 years old, perhaps you are not even aware of the day of 13" diameter rims on the small economy cars like the Ford Escort, and how these tires would last "forever" (certainly by modern terms). I'm not saying we need 13" tires on all cars or anything, but we really need to look at the impact that decisions like selecting the biggest wheels and tires possible for our automobiles can have on the envirionment. If you want some light reading on the matter, check out this 2004 USGS article on Tire Wear as a source of Zinc (pollution) to the Environment - it has all sorts of other neat tire-wear and pollution data in it too.

We can't just talk about making the environment cleaner, we need to have our actions reflect the essence of this talk. Car companies are advertising all over the place about going "green" and all, and I really think automobile manufacturers need to consider the tire side of the green equation too.

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