Oil Change Calculator

Oil change intervals depend on several factors: oil type, driving conditions, and vehicle age. Modern vehicles with synthetic oil can often go 7,500-10,000 miles between changes under normal conditions. Conventional oil typically requires changes every 3,000-5,000 miles. Always consult your owner manual for manufacturer recommendations specific to your vehicle.

Conventional oil is refined from crude petroleum, while synthetic oil is chemically engineered for superior performance. Synthetic oil provides better protection at extreme temperatures, resists breakdown longer, flows better in cold weather, and typically allows for extended drain intervals. Synthetic blend combines both types for moderate improvement at lower cost than full synthetic.

Severe driving conditions include: frequent short trips (under 5 miles), extensive idling, stop-and-go traffic, towing or hauling heavy loads, dusty conditions, extreme temperatures (below 0°F or above 90°F), and off-road driving. These conditions cause oil to degrade faster and require more frequent oil changes, typically at 50% of the normal interval.

Yes, you can safely switch from conventional to synthetic oil at any time. Synthetic oil is compatible with conventional oil and will not harm your engine. In fact, switching to synthetic can provide better protection, especially for older engines or those operating in extreme conditions. There is no need to flush the engine when switching.

Driving past your oil change interval allows oil to degrade and lose its protective properties. Old oil becomes contaminated with combustion byproducts, dirt, and metal particles. It loses viscosity and can turn to sludge, leading to increased engine wear, reduced fuel economy, overheating, and potentially catastrophic engine failure if neglected long enough.

You should change oil based on whichever comes first: mileage or time. Even if you do not drive much, oil degrades over time due to moisture accumulation and oxidation. For conventional oil, change every 6 months regardless of mileage. For synthetic oil, every 12 months is typically acceptable. Low-mileage drivers should follow time-based intervals.

Yes, use the oil weight (viscosity) specified in your owner manual. Modern engines are designed with tight tolerances that require specific oil viscosity for proper lubrication and performance. Using the wrong weight can cause inadequate lubrication, increased wear, reduced fuel economy, and potential engine damage. In extreme climates, your manual may specify alternative weights.

High mileage oil (for vehicles over 75,000 miles) contains additives that help condition seals to reduce leaks, minimize oil consumption, and reduce wear in older engines. If your older vehicle burns oil, leaks, or has over 100,000 miles, high mileage oil can be beneficial. However, if your older engine runs well without issues, standard oil is fine.

Changing your own oil can save money if you have the proper tools, space, and knowledge. You need a jack/ramps, drain pan, wrench for the drain plug, oil filter wrench, and proper disposal method for used oil. However, many quick-lube shops offer competitive prices including disposal and multi-point inspection. Consider your time, ability, and cost when deciding.

Never pour used motor oil down drains, on the ground, or in trash. Used oil is toxic and a single quart can contaminate thousands of gallons of water. Take it to a recycling center, auto parts store, or quick-lube shop that accepts used oil for free. Many municipalities have hazardous waste collection programs. Used oil can be re-refined and reused.