4. Routine maintenance, inspection and operational testing of the emergency generator and associated. components must be overseen by a properly trained person [see MSFC(07), Sec. 604.5; NFPA. 99(99), Sec. 3-4.4.1.1(b)3; NFPA 110(99), Sec. 6-4.7; NFPA 110(02), Sec. 8.4.7].
Replace the tires at least every 6 years. If you're not sure, the minimum replacement time that is recommended by the NHTSA is six years regardless of use, with 10 years being the maximum service life for tires. Check your owner's manual for specific recommendations related to your car.s the tires wear, these bars will become flush (level or even) with the tire's tread. At this point, it's time to replace the tires. 3. Check the tread by using the penny test.  Take a penny, and place it upside down with Lincoln facing you in the center of the tread (at the thickest part of the tire).
Knowing when to replace your carâs tires isnât an exact science. A lot of factors determine when you should buy new tires. Generally, though, you can follow these four tips to know when your car needs new tires. Replacing Tires by Mileage. The average tire can handle about 40,000 miles of travel before it starts becoming unsafe. That number depends on the vehicleâs weight, weather conditions, the types of surfaces you drive on, and how many nails you run over. In other words, donât take this number as a certainty. If your tires are reaching 40,000 miles, though, itâs time to take a close look at them. Theyâre probably due for a change.