LogFAQs > #986785216

I had trouble changing a tire the other day, but only because the damn thing was badly stuck on the hub. I finally called AAA because I couldn't get it to budge, but then while I was waiting I got the idea to turn the steering wheel all the way over so I could reach behind and bang on the back of the tire with a dead-blow hammer, which I fortunately carry in my car all the time. That finally popped it loose so I canceled the AAA call and finished changing the tire myself. I probably couldn't have gotten it loose alone if it was the rear wheel.

Before cars had computers in them, you literally had to tune up your car at least twice a year because as the temperature would change, the density of the air would change, and thus the amount of oxygen available to the engine. A tune up would adjust the air-fuel ratio to keep it as close as possible to the stoichiometric point, 14.7:1 for gasoline. Modern cars use sensors to continuously make these adjustments so they nearly always operate at stoich.