The other day, I noticed a light on the dashboard of my Honda Fit that I hadn't seen before. It looked like this and it was still on after a while.
http://dashboardsymbols.com/the-symbols/
I looked it up in the manual and thought it said it related to the brake system. I made sure the parking brake was completely off but the light didn't go out. I called the garage.
They said it wasn't about brakes but about the pressure in the tires. I learned that the sensor system turns the light (light = a "tell-tale", according to the site linked above) when the system detects a change in the tire pressure of 2 lbs or more. I am used to reading the target air pressure from the side of the tire itself but I had been told before that the standard pressure in today's cars is 32 lbs per square inch (psi). But this time, the mechanic chief said that since our weather had gotten colder (it is 45° F outside right now at 9 AM), that company has changed the current tire pressure target to 34 psi. After fixing me up, I was told the tires had been inflated to 36 psi.
Why? The weather has gotten colder but it has a long way to go to reach its coldest point. Honda and many other companies want to be environmentally smart. If the tire pressure is too low for that tire's shape and engineering, the miles per gallon will be lower that it could be. (I don't know how much lower.) If the tire pressure is too high for the design of the tire, the tire will wear out faster. Not only does that increase the need for tires but it also puts some yucky tire particles in the atmosphere. As the temperature drops, so does pressure. The guys at the garage are trying to compensate for the coming cold with higher pressures.
The manager of the garage told me that I could go to some other places in town and have my tires filled with nitrogen, which holds a steadier pressure at a wider range of temperatures than ordinary air but the cost is currently $20-25 per tire. Of course, refilling with air at a typical gas station will dilute the nitrogen, eventually needing another nitrogen filling. All that from a tell-tale light on the dashboard.
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Bill
Main blog: Fear, Fun and Filoz
Main web site: Kirbyvariety
