Misinformation about synthetic oil vs conventional oil in older cars still populates the Internet and some auto repair shops. Some people still erroneously think that synthetic oil can be “too slippery” and result in leaking seals. Or synthetics will cause roller followers to slip or skid.

Like many popular misconceptions, the idea that synthetics cause oil leaks is based on truth.

Back in the 1970s, some synthetic oils were formulated using chemicals that were harder on seals than the chemicals in modern synthetics. Early formulations sometimes resulted in oil leaks, which gave rise to the myth that exists today. Modern synthetics, however, are much more advanced and use chemicals that are fully compatible with seals. A properly formulated synthetic conditions seals and helps maximize their life and effectiveness.

Synthetics can reveal the true condition of seals
Sometimes, switching to a synthetic oil in an older, high-mileage car can result in leaking seals, but it’s not the motor oil’s fault.

The seals and gaskets in older engines can dry, become brittle and crack. Sludge that has accumulated over the years, however, can cover the cracks and prevent them from leaking. It’s like using spackle to cover cracks on a wall. The sludge effectively helps the worn seals do their job.

A good synthetic uses potent detergent additives that clean sludge, revealing the true condition of the seals. Cleaning the sludge from the worn seals leads to leaks, which the driver associates with the synthetic motor oil.

If you suspect your older, high-mileage engine falls into this category, you may want to leave well enough alone and continue using conventional motor oil.

How to switch to synthetic motor oil
Given its superior performance, many motorists are making the switch to synthetic motor oil for the first time. Several automakers install synthetic lubricants at the factory due to their improved protection, which further encourages motorists to use synthetic motor oil.

If you decide to opt for a full synthetic oil change next time your vehicle is due, here’s what you need to do first: nothing.

That’s right. You need not do anything special to switch to synthetic motor oil. Simply drain the conventional motor oil and install synthetic motor oil of the correct viscosity for your engine.

Consider an engine flush
Depending on the condition of your engine, you may want to perform an engine flush to remove sludge prior to switching to synthetic motor oil.

Synthetic motor oil beats conventional motor oil
Synthetic motor oil outperforms conventional oil on nearly all counts. It delivers excellent protection against wear, damaging deposits and chemical breakdown. Switch to synthetic motor oil to help your engine last longer and deliver maximum power and performance.