Can I Switch Back to Regular Oil After Synthetic Oil?

Regular truckofmine.com readers know the relationship between regular oil changes and engine life. We’ve pounded the point home with a series of posts revolving around the importance of changing car oil in time, how to change the oil, and what grade oil to use. 

However, we haven’t touched on the switching from synthetic to regular as you please or weighed in on what oil type is better to debate. Today, we will get our hands and wrenches oily as we try to help you figure out if you can switch back to regular oil after using a synthetic blend or not.

What is Conventional Oil?

Conventional motor oil (mineral motor oil) has been around for as long as internal combustion engines have needed lubrication.

It is a crude oil product created when the crude is refined just right to give it good lubricating properties. However, since it is a natural product, it still has some inherent natural inconsistencies that no amount of purification can fix. This is where synthetic oil comes in.

Nonetheless, it is a cheap and working solution that though not as good as synthetic oil, makes sense if your engine can take it and you remember to do your engine oil change pit stops on time.

What is Synthetic Oil

On the other hand, synthetic oil consists of lab-made compounds generated by breaking and rebuilding petroleum molecules to give the perfect structure and characteristics for lubricating an engine.

Due to their tightly controlled structure, they are the perfect substitute for conventional oils. The manufacturer can predict and guarantee lubricant behavior under different temperatures and stress.

This gives engine manufacturers something concrete to work with when designing their engines since they know exactly how the recommended oil will interact with the engine at different temperatures.

Apart from the laboratory modifications, synthetic oil also has additives designed to clean and protect your engine. Other additives will also:

  • Improve the oils viscosity index giving it better lubricating properties even at very high temperatures
  • Improve oxidation resistance hence improving the oils’ lifespan
  • Give Low volatility
  • Improve cold cranking properties

So, Can I Switch From Synthetic to Regular as I Please?

You can switch from synthetic oil back to regular – as long as your vehicle manufacturer doesn’t insist on using synthetic oil in your engine.

Some manufacturers recommend or even insist on nothing but synthetic in their engines. Living by this guideline will help you avoid unprecedented problems and ensure you don’t void your warranty.

However, if your manufacturer recommends oil grades but doesn’t touch on whether it should be synthetic or mineral oil, you can switch between them as you please as long as you get the viscosity right.

The oils grade name denotes viscosity. Use the oil grade chart in your user manual or specific to your vehicle to determine what oil grade you should be using depending on prevailing temperatures.

Oil grades are named with a low-temperature rating and a high-temperature rating. You will be looking for nomenclature in the following format.

What Are the Benefits of Sticking to Synthetic Motor Oil

While switching from a synthetic blend to regular oil might seem to save you some bucks in the short run, you will be preceding a wide range of benefits that will give you even better savings in the long run.

Better Engine Wear Protection

Since synthetic oil is specifically engineered to lubricate an engine and improves on mineral oil imperfections, it gives better lubrication across a wide range of temperatures.

The oil blend is so good at wear protection thanks to its predictable behavior and other additives geared to reduce deterioration in the lubricant and engine parts’ tear and wear.

Stable Viscosity Over a Wide Range of Temperatures

Instead of compensating for low viscosity at high temperatures by starting with a thicker oil with greater viscosity, synthetic oils work by creating a product whose lubricating capabilities stay as even as possible across the engine’s operational temperature band.

This means you won’t have to struggle with a very heavy oil with the engine cold just so that it doesn’t think out too much to offer any protection once your vehicle warms up.

Better Fuel Consumption

Since you will be using the perfect oil weight for your temperatures thanks to a better viscosity index, your engine won’t have to circulate heavier than necessary oil. This reduces energy waste giving you more brake horsepower per fuel consumed.

You could have considerably better gas mileage than someone using mineral oil in the long run.

Good Turbocharger Protection

If your vehicle has a turbocharger, you will get a better engine and turbocharger lifespan from using synthetic oil. Forced induction engines work at their limit and need all help they can get to stay reliable for years.

Sticking to high-quality synthetic oil and changing it on time is a good way to keep your engine and turbos spinning happily for thousands of miles to come.

Fewer Impurities Means Less Sludge Buildup

With fewer impurities in synthetic oil and more cleaning additives, you should expect synthetic oil to clean your engine better and formless sludge buildup over time. Less sludge means a clean and healthy engine and as close to stock power output as possible.

Some people say their engines can go longer before oil changes when running on synthetic oil. While the oil might still be good, don’t use this myth when maintaining your vehicle. Stick to the manufacturer’s recommended service interval regardless of what your synthetic oil sales literature recommends.

Common Synthetic Motor Oil Myths 

There are so many myths about synthetic oils we feel winding up without touching on them will be a disservice. Here are the top three you should be aware of.

You Can Never Go Back Once You Go Synthetic

Switching to synthetic isn’t one-way traffic. You can always go back to conventional oil unless your manufacturer recommends or insists on using synthetic oil in your engine. Otherwise, switching back will see you forgo synthetic motor oil benefits.

Some of the side effects could start showing in a while, but that doesn’t necessarily mean the switch ruined the engine. It’s just that your engine no longer reaps of the benefits of that glorious synthetic lubricating juice.

Switching to Synthetic Oil Will Cause Leaks

Some people argue that going synthetic will lead to oil leaks that wouldn’t have happened when running mineral oil. While synthetic oil is thinner and lighter, it shouldn’t leak if the gaskets in your engines are perfect.

While it could ooze through small pores that might contain mineral oil, you might have missed slower leaks with mineral oil. The solution would be fixing the gaskets and containing the leak, not switching back to conventional oil.

New Engines Must Be Broken in With Mineral Oil

I spent days pouring over manufacturer recommendations and talking to fellow car enthusiasts and mechanics. I can tell you for a fact there is no manufacturer whose manuals recommend putting in conventional oil to break in a new car.

Most vehicles now ship out with synthetic oil, meaning you break in your vehicle with synthetic oil. If conventional oil is necessary, they would have it preloaded and mention it somewhere in the user manual.

If you buy a crate engine, you will have to fill the engine with oil yourself. Start it off on a healthy dose of high-quality synthetic oil. Don’t even contemplate using mineral oil unless it is an old classic engine and the manufacturer explicitly says it can’t handle synthetic oil.

Is Switching to Full Synthetic Oil in Higher Mileage Vehicles Useful?

Yes. Switching to full synthetic oil will benefit your high mileage vehicle. Better lubrication and improved cleaning will improve your performance and engine lifespan. It could also help you identify very slow leaks and fix them before it is too late.

What to Do Before Switching Back to Regular Oil After Using Synthetic Oil

There are really no prerequisites to switching back to regular oil after synthetic. If you are convinced that’s the way, just fill in the mineral oil as you would during a regular oil change. There’s no need to flush your engine or anything fancy. All you have to do is ensure you get the right oil weight for your engine and the weather.