Diesel oil, as we discussed earlier, has a lot of zinc in it! That's why some gearheads use it instead of ZDDP additive to protect the innards of their classic car's engine. The problem is ...

You bring your car to the auto repair shop and they slap a sticker on the windshield: change your oil again in 3,000 miles or three months. You probably knew that the 3,000-mile interval was ...