People are not too stupid to always do the right thing; sometimes they are ignorant of the right thing and just do what they have always done; sometimes they just forget to do the right thing and sometimes they think that doing the right thing is not as important as doing something else.

For Paul K:

You are taking the subject out of context: when one optimizes a variable, one considers the effects (all the effects) of each value and picks the value that gives the best performance in the multidimensional space of all the outcomes that that variable affects. That is presumably what the manufacturer did when he calculated a value for tire inflation to put in the owners’ manual. Note that Toyota chose to select not only the tire pressure but a special tire design that has less rolling resistance that the “normal” tire design.

Maximize mpg. Pump your 32 psi tires up to 45psi for amazing results. Then as your bouncing off the road into the ditch contemplate the insanity of optimizing tire inflation for safety rather than mpg.

[JR: Proper tire inflation increases safety and mileage.]

1. I could not find a single 2008 auto which had a tire pressure management system (TPMS) as standard equipment. All the car specs I reviewed (not many, as it was getting late) list TPMS as “Available”. The rule reads as follows:

“This final rule establishes a new Federal motor vehicle safety standard (FMVSS) requiring installation of a tire pressure monitoring system
(TPMS) capable of detecting when one or more of a vehicle’s tires is
significantly under-inflated.”

The rule is effective for all light vehicles of model year 2008. I don’t know what part of “requiring installation” I don’t understand, but apparently I don’t understand the rule.

2. The standard requires the system to notify drivers when tires are 25% under-inflated. This is a SAFETY rule, not an efficiency rule. Notification at 10% is needed as an efficiency standard.

3. TPMS technology is advancing rapidly, and there are several companies focused on developing new systems. It appears the biggest problem has been powering direct systems (in which a pressure gauge is attached to the wheel with RF communication to a display on the dashboard). These systems have been using batteries in the past, which have short lives when attached to fast spinning hot surfaces, like an automobile wheel. Of course, there’s a lot of energy in them wheels, and they are figuring out ways to use that rather than batteries.

Funny story on that law. The nader people sued to block it. Successfully — pushed the law back 5 years. Safety — they wanted a stricter standard. My guess is not implementing the law back in 2004 cost on about 50-100K b/d of oil.

Sigh.

A better strategy would be to make sure all new cars have readouts of mileage (trip computer), and move to measuring it by volume not by fuel injector sensors.