It sounds like a simple question that begs a simple answer. But, the truth is, there is no one simple, right answer to oil & lube change frequency, unless the answer is “It depends.”
In every case, the best answer starts with recommendations from the people who designed, built, and warranty the engine: the vehicle manufacturer. Most of what you need to know about your vehicle, and how to get the best service and protect your warranty, is in your owner’s manual packet. So let’s look in the index under “Scheduled Maintenance Services” or in the Owner’s Manual Supplement under the same topic.
Back to your question: How often should I change my oil? Again, the owners’ manual will specify recommended intervals, usually by mileage and/or time, whichever comes first: 3,000 miles or three months is an example of one popular recommendation. But look closely, as there are usually two schedules (remember “It depends”?)
There will be a “Short Trip/City” and a “Long Trip/Highway” oil & lube change schedule.
The names may change, like “Severe Duty” and “Light Duty,” but there will be explanations of which driving habits require which schedule. You have to read the fine print. While you may assume that excessive idling (like taxicabs) or extreme high-speed use or towing qualify for “severe,” the fact is that the driving YOU do, such as short trips, the frequent starts and stops during which the engine does not reach the operating temperatures that burn off moisture and prevent oxidation also are considered “severe” conditions and require the shorter change interval. So, a couple, one of whom is in sales and covers four states may need to change the oil in the company car every 7,500 miles or every 12 months (whichever occurs first) while the partner with an identical vehicle who only makes frequent, short trips may need to use the 3,000 miles/3-month service interval!
Oil change service: don’t forget the bonuses
Although manufacturers brag about extended service intervals (meaning less hassle and lower costs for the vehicle owner), there are many positives that happen during an oil & lube change. Someone is lubricating suspension components such as tie rod ends and ball joints (where grease fittings are available), topping off all under-hood fluids, checking filters (air, cabin, fuel), usually rotating your tires, checking tire air pressures, checking tires for cuts, bruises, bulges and uneven wear, and even looking at brakes. Most shops also will check your wiper blades (which you may remember only when it’s raining), lights (headlights, brake lights, running lights, turn signals, back-up lights, side marker lights, and license plate lights), and advise you of their findings. And overlooked components such as door hinges receive a squirt of needed lubrication during a professional oil change service.