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).
Compressed Air v Nitrogen. Aircraft and racing car tyres have been using purified nitrogen to inflate tyres for years as tyre pressure is reduced at a much slower rate. The compressed air which is usually used to inflate tyres is made up of 78% Nitrogen, and also contains Oxygen and water vapour. Once your tyres have been filled with Nitrogen it is important that you only use Nitrogen when topping up. 2  If you are in a situation where you can only re-inflate with compressed air you must deflate the tyre fully before you can re-inflate with Nitrogen.