Your mother always told you that clean is important. After all, you never know when you might break a leg and the paramedics have to cut your underwear off on the scene exposing your skid marks. But that’s underwear. We’re here to talk about engine oil. Keeping the oil clean is very important to your car’s health. We accomplish this by performing regular oil changes using a high quality oil (preferably synthetic oil) and a new filter. Keep this level of maintenance up and your engine could last half a million miles without needing a rebuild. There are a number of companies out there offering an additional tool to keep your oil clean — an oil bypass filter. It’s basically another oil filter added to the system. Manufacturers of oil bypass filtering systems claim they can continually filter out particles as small as one micron (don’t ask me how big a micron is, who knows), keeping your oil particulate-free and allowing you to go much longer between oil changes. The technology has been in place for some time and is used regularly on fleet vehicles and other trucks that really rack up the miles in a hurry. But do you really need this added protection for your car’s engine? Depending on which pocket your keys are in, the research on the subject can go either way. Unfortunately the only “research” out there on car and light truck engines is offered by the companies pushing the oil bypass filtration systems. This doesn’t mean it’s not accurate, but it’s hardly independent. The lack of concrete lab findings leaves it to guys like me, and eventually people like you, to form your own opinions. My opinion? I think adding one of these systems to a car or light truck engine amounts to severe overkill unless you’re driving 100,000 miles a year. The systems add between 1 and 4 quarts of extra oil to the car, along with a bunch of new fittings, hoses and other connections. If one of these connections were to fail, you’d have zero oil pressure and no oil in a hurry, leaving you stranded. Besides, research has proven that using quality oil and changing it on a regular basis (the new standard is 5000 miles) is enough to get you hundreds of thousands of miles out of an engine. Synthetic oil doesn’t break down the same way mined oil does so won’t add particulates to the oil mixture. Ironically one of the companies pushing a bypass system also sells their own brand of synthetic oil which doesn’t break down, so why would you need the extra filtration? In defense of the guys who make these systems, the independent testing performed by the US Department of Energy showed a huge savings in the amount of oil a diesel-engined bus would need over the course of a year, thanks to many fewer needed oil changes. But my gavel still falls on the “no” side. I just don’t see the need to add an expensive set of extra plumbing to my V6. News source: About Auto Repair