Engine Oil Basics: Conventional vs. Synthetic vs. High-Mileage Oils

If you are like most drivers, you want your vehicle’s engine to last as long as possible. One of the most important things you can do is pick the right engine oil and change it on schedule. But with so many options on the shelf, it can get confusing. Let’s break down the basics of engine oil types—conventional, synthetic, and high-mileage—to help you make the best choice for your car or truck.

Conventional Oil

Conventional oil is the oldest type and is made from refined crude oil. It’s been the standard for decades and works well in older engines or vehicles driven under normal conditions.

Pros:

  • Affordable and widely available
  • Works fine for basic, everyday driving
  • Good option for older vehicles that have always used conventional oil

Cons:

  • Breaks down faster than synthetic oil
  • Less effective in extreme temperatures
  • Needs to be changed more often

Best for:

  • Older vehicles
  • Drivers who stick to shorter trips and light loads

Synthetic Oil

Synthetic oil is made in a lab for better performance. It’s designed to protect engines in all types of weather and driving conditions.

Pros:

  • Flows better in cold weather and protects better in extreme heat
  • Lasts longer between oil changes
  • Helps boost engine performance and fuel efficiency
  • Keeps engines cleaner by reducing sludge and deposits

Cons:

  • Costs more than conventional oil
  • Not always necessary for older, high-mileage cars unless recommended

Best for:

  • Newer vehicles
  • High-performance engines
  • Drivers who tow, haul, or drive in extreme heat or cold
  • Anyone who wants longer intervals between oil changes

High-Mileage Oil

High-mileage oil is made for vehicles with over 75,000 miles on the odometer. It usually has special additives to help protect aging engine seals and reduce oil leaks or burning.

Pros:

  • Helps reduce oil consumption and leaks
  • Conditions engine seals
  • Cleans sludge from older engines

Cons:

  • Costs a bit more than conventional oil
  • Not needed for newer or low-mileage vehicles

Best for:

  • Vehicles with more than 75,000 miles
  • Cars that have minor oil leaks or use more oil than usual
  • Drivers who want to extend the life of their older vehicle

Best Practices for Choosing Oil

  • Always check your owner’s manual for the recommended oil type and viscosity
  • If you drive short trips or in heavy traffic often, consider synthetic for better protection
  • For older vehicles, high-mileage oil can help keep things running smoother
  • Change your oil on schedule, no matter the type you use
  • If you’re not sure which oil is right for your car, our ASE-certified technicians are happy to advise you

Choosing the right engine oil can make a big difference in how your vehicle runs and how long it lasts. If you have questions or need an oil change, come by any one of our convenient locations. Our ASE-certified technicians always welcome questions and are here to help keep you on the road.