Human interface is supposedly important to engineers. In particular, I was taught that an object should be designed so that the effort required to perform the tasks that will be performed most often is minimized, while tasks that will be performed only occasionally are allowed to be somewhat more complicated. This is why, for example, opening and closing your garage door takes a single button push, while slaving an additional remote control to the opener is allowed to take five or six steps, plus a glance or two at the owner’s manual.
I’ve often wondered why nobody ever taught this principle to tire manufacturers.
We are told, for the sake of safety and “saving energy,” to check our tire pressures monthly, if not weekly. It should be clear that next to just driving around on them, checking the pressure is the task I perform on my tires most often.
Why, then, is the inflation pressure on a tire rendered in minuscule four-point type, practically buried under the edge of the wheel rim?
Compare, for example, the bold, two-inch-high presentation of the tire’s size designation. This supremely visible datum is used precisely twice in the life of a tire: once when the floor-walloper at the tire shop has to pick the right tire off the pile, and once more when he has to replace it. Then, of course, there’s the giant brand name on the tire, so the manufacturer will get his free advertising wherever I park. I don’t begrudge the self-promotion, and I don’t begrudge making the mechanic’s job easier… but how about the same consideration for the tire owner?
Instead, at maintenance time, we are all forced to locate two or three tiny digits in some unknown position and orientation, from an upside-down orientation of our own, and then read them through road dust, grime, and tar, assuming they haven’t been entirely scraped off by a chance encounter with a curbstone. As I get older, I discover that bifocals don’t work on objects close to the ground, and neither do my knees. Hm. Is that a 3 or an 8? Hand me a wet toothbrush.
Yes, I see you purists waving your hands frantically, eager to tell me that I should be looking on the doorframe of the car for the “proper” inflation pressure, and not going by the information printed on the tire. I shall claim my “fogy prerogative” by mentioning that I have been inflating tires by the stamped pressure for 50 years, long predating the relatively recent introduction of those sissy DOT door labels. But fine—let’s do it your way. One of you purists please go find this sticker on my horse trailer; another one, check for it on my RV; three more of you cover my tool trailer, utility trailer, and ATV; and the rest of you can point out to me the DOT labels on my wheelbarrows, tiller, and bicycles. (I hope this exercise also helps explain why I don’t just “remember” the proper pressure to use once a month.)
Ah, the guy at the RV is beaming because he actually found the sticker! But what he didn’t notice is that the tires on the RV have been upgraded to a higher load rating than the weaker factory originals, so the sticker pressure is no longer applicable. Age and treachery again foils youth.
Anyway, I’ve addressed this problem in my own household by attaching self-adhesive vinyl numbers to my vehicles and tools in the area of the tires, so I can just look and then pump air. (Didn’t work real great on the tiller, but you can’t have everything).
We shouldn’t have to do things like this to make up for the user-hostile practices of Big Rubber. Meanwhile, the true engineer fixes problems caused by lesser engineers and then moves on.