I got my mom and dad each their own portable air compressor that plugs into a car's outlet as well as a tire gauge. I begged, pleaded, and regularly reminded them to check the tire pressures of their vehicles to no avail. When I got a chance to visit them I'd check and adjust their tire pressures for them. Well, they bought a brand new Saturn Aura and she told me the car talked to her and told her to check the tire pressures because one was low. She said she instantly thought of me. Now if we could only do the same with my dad's van. Can you imagine how much fuel would be saved if people would at the very least inflate their tires to the vehicle's recommended psi? What's even more frustrating is the autoshop guys who, no matter what the vehicle recommended psi is, they always go with the standard 32 psi all the way around. I make it a point to check my tire pressure the morning after I've taken my car in for an oil/filter change.