Here's my take on synthetics and some general maintenance tips:
1.) If you drive an older model (pre-synthetic days), then don't use synthetics. They do not swell the older seals like conventional does and can result in leaks (proven mechanical fact).
2.) It is not the OIL that kills the engine, it is the DIRT! I use conventional oils changed at 3,000-4,000 miles with a Wix oil filter change. I change my Wix air filter at 20,000 miles max (usually between 15,000-20,000 during an oil change). I do inspect it every other oil change. Oil brand does not matter to me, I buy the cheapest name brands I can get - but the API service rating does. See:
http://www.api.org/certification-pr...iesel/Publications/MOM_GUIDE_ENGLISH_2013.pdf
3.) There are a very few filters worth a damn. Wix (which makes NAPA and Carquest brands too), Purolator, Baldwin. They go downhill after that. This is from my own personal experience cutting oil filters open as a parts counterman and also from comparative studies. Use good brand-name oil and air filters. Remember, DIRT kills the engine.
4.) Some newer cars (including the Nissan Versa) do not use in-line gas filters, only the one on the fuel pump in the tank. If yours has an in-line gas filter, change it 3/4 earlier than the manufacturer recommends (if they say 100,000 do it at 75,000). This prolongs the life of injectors.
5.) Do not allow your car to go below 3/4 tank of gas very often if you intend to keep it as a high-mileage car. Any contaminants in gas (and they are few now, but still present) will settle into that bottom quarter-tank. Constantly running near dry before filling up drives these particles through your fuel pump, into your fuel filter, and to a degree, into your injectors. That shortens the life of all those components. Add an injector cleaner to your gas every third oil change.
6.) Don't change auto transmission fluid as long as it is red on the dipstick and smells fine (not burnt smelling). Time and again, changing auto trans fluid just because "it's time" has resulted in transmission problems. This is the experience of many pro mechanics talking here. Just keep it full and not overfilled.
7.) Likewise, check and fill manual trans fluid every other oil change for newer cars and every change for high mileage cars.
8.) Change plugs every 100,000 miles if platinums. (Have fun on that Versa, where it requires taking the entire top end off the engine to get to them! About a $300 job from a mechanic. Ludicrous!)
9.) Do not allow corrosion to build up on battery terminals. Duh, right? BUT likewise, do not allow DIRT to build up on the battery case. Moisture in the air during high humidity / rainy periods can create a tiny connection through dirt between terminals that saps the battery longevity and makes the charging system have to charge deeper under taxing circumstance, shortening the life of both. Batteries are high-priced now! I get 10 years minimum out of my 5-year warranty batteries just by keeping the case and terminals clean. Oh, and if you have battery posts, those little terminal post washers? They work.
10.) When topping off with DOT 3 brake fluid, use fresh fluid. When capping the plastic fluid bottle, squeeze the sides to raise the level to the top before capping off. This helps keep moisture out of the fluid.
11.) Changing your own oil makes your car last longer because you can spot other problems early. It is a wise investment of a couple hours on Saturday. I got 289,000 miles out of my original brake rotors on the Sentra by spotting pad wear during oil changes and changing them ahead of failure, for example.
12.) Check your tire pressure and top off at every 3,000-mile oil change. It's the single best thing you can do to improve gas mileage. It's also makes common sense that the easier they roll, the easier it is on your drivetrain.
