When the earth was young and mosquitoes the size of space shuttles swooped from the Triassic mist and drained the blood from sauropods in a single suck, car guys changed their own oil, swapped their own brake pads, adjusted their own valves.
We still do these things, and for good reason. Caring about a car and laying your hands on it not only changes your relationship with the car, it changes your relationship with yourself. Sure, it's messy. The containers of old oil accumulating under your deck will drive your neighbors nuts. So why do it? Because it's the gateway drug. Because it gives you the chance to commune with something cool. Because while you're under there, you can inspect the bottom of the engine and spot that bulging power-steering hose or frayed alternator lead. Will Kwik Loob do that? Doubtful.
First step: Check your owner's manual. It will tell you the quantity, type, and weight of oil you need. Oil weight is expressed as a two-part number, like 5W-30. Newer cars maximize efficiency by using extremely light oil, as low as 0W-20. Older cars enjoyed only in summer often take heavier oil like 20W-50, perhaps switching to 10W-40 if driven in colder months.
Your owner's manual will also tell you the recommended oil type. Grossly speaking, this cleaves into conventional (sometimes called "dino," a tongue-in-cheek reference to nonsynthetics originating from decomposing dinosaurs) and synthetic, but there are now many different kinds of synthetic as well as conventional/synthetic blends. I have a 1999 BMW Z3 M Coupe in which I would never use anything other than BMW-labeled Castrol synthetic 10W-60, but I take far greater liberties with my other cars. Read and see what a quorum of folks recommend for your car, as well as esoterica such as whether it needs blended-in additives like ZDDP (zinc dialkyldithiophosphate, a once-common oil additive still used for cars with flat-tappet/non-roller-bearing engines). Similar things hold true for oil-filter choice. It's hard to go wrong buying a logoed OEM filter at the dealer, but whether that's strictly necessary is debatable.
The mechanics of changing your oil consist of getting the oil out, getting the old filter out, putting in the new filter, and pouring in the new oil. Draining the oil out of the pan requires a wrench the size of the drain plug and an oil catch basin. That's still the best way. There are also vacuums that suck the oil out the dipstick tube, meaning you don't need to worry about overtightening or cross-threading the drain plug. This is not as thorough and not recommended, unless you dig pretending to be that big mosquito, sucking the oil out of sauropods.
Filters come in spin-on and cartridge versions. Removing the spin-on type almost always requires an oil-filter wrench, basically a circular strap with a handle. They come in several sizes; take a spare filter to the store and buy one that fits. To remove the filter, position a catch basin beneath it, unscrew it—if there's any possibility of the oil wrench touching the positive on the starter motor, disconnect the negative strap on the battery first—clean the mating face, fill the new filter three-quarters full of clean oil, smear clean oil on the rubber seal, and screw it on. Many filters say to tighten until the seal touches metal, then add three-quarters of a turn. Warning: If you overtighten a filter with a dying strain, it will be difficult to get off. Cartridge-style filters are a bit more challenging and often require a big socket. But even with that complication, this is a rewarding first repair on your baby.
Adding new oil used to be easy. There was nothing in the way of the oil cap. You could crack open a quart, dump it in, and not spill a drop. Nowadays it's often difficult to get a straight shot at the oil reservoir, and damned near impossible if you're pouring from a gallon jug. Buy a funnel.
And, really, don't accumulate used oil under your deck. Man up, pour it into the bottles it came in, and take it back to the parts store for recycling. No need to be a dinosaur about it.
Rob Siegel is a writer and renaissance wrench from Boston. His latest book, Memoirs of a Hack Mechanic, is available from Bentley Publishers.
USE YOUR FINGER TO APPLY A BEAD OF OIL AROUND THE FILTER GASKET.
DON'T BE AFRAID TO DO THIS YOURSELF. IT'S EASY AS TOAST.
PAY A TEENAGER: IT'S BETTER TO LET KWIK LOOB CHANGE YOUR OIL THAN PUT IT OFF TOO LONG.