Proper Maintenance for High-Mileage Vehicles


Proper maintenance is vital to prolonging the life span of vehicles, and this is particularly true for high-mileage cars, which have more than 75,000 miles on them.


In the past, car owners didn’t expect their vehicles to log in more than 100,000 miles, but having cars with 200,000 miles is no longer surprising nowadays. This trend can get credit for the growth of the used car warranty market.


According to CNBC, the average age of a car on US roads went up to 12.1 years in 2021 from 11.9 years in 2020. Several technological advancements may have led to the increase in vehicle life span. These include electric power trains, improved performance, higher fuel mileage, and safety features.


Owners of high-mileage vehicles, including fleet vehicles, follow different preventive maintenance practices to keep them in tip-top shape. If you’re wondering what these practices are, here are a few that you can try out.


1. Follow the Service Schedule

High-mileage vehicles, just like new cars, need routine checkups to ensure that everything’s running without a hitch. You may even argue that they need regular maintenance more than new units. These checkups are sometimes called preventive maintenance. The goal is to find anything that needs fixing before it worsens, keeping the car in running shape.


A car mechanic or technician looks at different vehicle parts during these sessions, such as the tires, battery, and fluid levels. Place special attention on keeping the vehicle sufficiently lubed and its filters clean.


2. Change the Oil Regularly

You could say that the oil is the car’s blood, and keeping it clean keeps the vehicle healthy. Regularly changing your car’s oil is essential in protecting engine parts from being damaged by heat and friction.


Only use high-mileage oil on the engine to help lower oil consumption, avoid leaks and seepage, and decrease emissions. Schedule your oil and oil filter change every 3,000 to 5,000 miles. 


3. Don’t Forget Your Fluids

Speaking of oil, it isn’t the only fluid in your vehicle that needs regular checking. It would be best if you also take note of your brake fluid, transmission fluid, coolant, power steering fluid, and even your windshield wiper fluid.


Ensure that these fluids are at their required levels and are working correctly. Add to low-level fluids and if the level is lower than usual, check for any sign of leaks. Repair any leaks and replace components that are beyond repair. You can use anti-leak additives the next time you fill the fluid tanks.


4. Keep the Fuel System Clean

Maintaining high-mileage cars should also involve fuel system cleaning. The presence of debris in fuel injectors causes clogging, disrupting fuel and air delivery to the engine. If clogging occurs, it will place additional stress on the engine, reducing its performance. Avoid this by adding the right fuel injector cleaner into the system to eliminate the impurities.


5. Swap Out Dirty Filter and Stretched Out Belt

While others may overlook car air filters, they are essential in preventing damage to the engine. Replacing a clogged air filter can increase fuel efficiency, reduce emissions, and prolong engine life.


A dirty air filter limits airflow to the engine, making it work harder and consuming more fuel. It may also lead to an air-fuel imbalance that affects exhaust emissions. Replace air filters every 12,000 miles to 15,000 miles. Intervals can be shorter if you regularly drive in dusty environments, though.


Meanwhile, it would also help if you replace the car’s timing belt once you’ve driven 60,000 miles. If you stretch the use of your timing belt, it can affect the engine’s performance. If it breaks, you could get stranded or get your interference engine damaged.


6. Take Care of the Battery

Performing maintenance on a high-mileage vehicle would be useless if the battery isn’t functioning correctly. A faulty battery means you can’t start your car.


Thoroughly clean the battery by removing any signs of corrosion on its top and cables. Use a non-metal brush for cleaning and dip it in a water mixture containing baking soda.


Get rid of any remaining rust around the cables and terminals by disconnecting the wires before scrubbing with a post cleaner. Check if the battery’s electrolyte level is approximately 0.5 inches deep, and add distilled water if the level is lower.


Be sure to charge the battery every six weeks by either driving the car or using a battery charger. If the battery loses charge, you can’t start the vehicle.


7. Don’t Let Your Tires Get Tired

It’s easy to forget about tires, but they play a crucial role in how your vehicle rides and how safe it is. If your tires get worn out or become out of balance, it could cause your car to pull or wiggle while driving, damaging other vehicle parts.


Always keep the tires inflated and maintain correct air pressure to prolong their life. Properly maintained tires give you better handling and fuel efficiency.


Whenever you go for an oil change, also ask for the tires to be balanced. Clean them regularly and check for wear. Replace them if the need arises.


8. Treat Your Engine Right

Notice how earlier sections emphasized that failure to maintain certain parts of the car could affect the engine’s performance. It’s because the engine serves as the heart of the vehicle.


If the engine isn’t working correctly, the entire car will not function properly. Proper engine treatment is imperative in maintaining high-mileage vehicles. You can do this by adding an engine treatment product to your oil or fuel tank. These products remove gunk buildup inside the engine. After doing this, there will be a noticeable reduction in vibration and engine noise. It can also improve engine performance.


9. Never Forget Cleanliness

Maintaining the cleanliness of a car may seem trivial to most people, but it’s an integral part of maintaining high-mileage vehicles. The paint and finish of a car become more vulnerable with age to rust. 


Regular washing and waxing are enough to prevent rust, but many recommend full detailing every couple of years. If possible, keep your vehicle in a covered garage or use a cover if you don’t have one to keep the car protected from the elements that promote rust formation.


Avoid getting tears and holes on your carpets and seats by vacuuming them regularly. Debris from food may attract insects that can cause damage to your upholstery.


Just because it’s old doesn’t mean your car should look old. Keeping a vehicle clean not only protects it from damage but also makes it look new.


10. Don’t Use Cheap Parts

Repairs can be a financial burden, especially when we don’t expect them, so it’s only natural for people to look for ways to save money. However, some people try to save a few dollars by buying cheap parts and fluids for repair and maintenance sessions.


Trying to save this way could cost you more in the future. Using the wrong oil or fluids could cause damage, which will then require additional repairs and cost you more in the long run.


Some companies even void warranties when they find out what caused the damage. Using parts and fluids that don’t meet the automaker’s specifications can diminish the car’s long-term reliability.


For example, some cars are designed to run on premium gasoline strictly. If you opt to use regular fuel, there’s a chance that the engine won’t perform correctly and even get damaged.


Meanwhile, manufacturers may only recommend premium fuel for some car models. This means that you can use lower-octane fuel because the engine-control system will adjust for you. On the other end, using premium gas on a vehicle designed to run on regular fuel would be a complete waste of money since it won’t impact your car’s performance.


11. Adjust Your Driving Habits

According to the Automotive Training Center, driving habits may significantly affect a car’s performance and longevity. Idling for 5-10 minutes is one of the most common practices for warming up a car. 


However, this practice only applies to decades-old cars and not most modern cars. It’s essential to warm up your vehicle during cold days, but idling beyond 30 seconds would be wasteful and harmful to the environment. 


Driving below 37 miles per hour during the first 10 minutes can warm up the engine without forcing it too much. Other habits you should avoid are driving too fast, hitting curbs, harshly shifting gears, off-roading, and trailer towing.



No matter which of these practices you want to follow to prolong your car’s lifespan, the important thing is that you understand the need to take care of your vehicle. Proper maintenance is the key to keeping your car running in its best condition regardless of mileage.