Yes, that title was a cheap ploy to get you in here and reading about the wonders of motor oil for your vehicle’s engine. No, we’re not going to be wrestling in oil, we’re going to do some mental wrestling about oil and which type is best for your vehicle. When it comes to synthetic vs conventional oil for your engine, there are arguments to be made on both sides regarding which is the better choice.
Ultimately, it really comes down to what you can afford and how much you care about your vehicle and its engine. Realistically, not everyone can shell out top-dollar for motor oil every few thousand miles when they need to change it. Fortunately, however, there are some compromises that can be made to get excellent performance, take care of your engine, and not break the bank while you do it. So let’s look at synthetic vs conventional oil and how they compare in a few specific areas, so you can decide which is best for you.
Where They Come From
Both synthetic and conventional oil come from the same source: the ground. Essentially, synthetic oil starts off like conventional, but it is refined and processed much more than conventional oil is. In fact, synthetic oil is processed so much that it’s manipulated at a molecular level to be more effective in engines. Some synthetic oil is completely made in a lab without being extracted from the ground first, but the majority is natural crude oil processed into refined mineral oil.
How Refined they Are
This is the major distinction between most synthetic oil and conventional oil. Crude oil is extracted from the ground and processed and refined into mineral oil that is good for lubricating the engine of your vehicle. If a manufacturer stops there, then you get conventional oil.
By taking that mineral oil and processing it further, refining it much more, then you get synthetic oil. This is refined and purified, with adjustments made to the molecules of the oil itself, to produce a final product that is much better at lubricating your engine.
Friction
To put it simply: synthetic oil is much better at reducing friction than conventional oil. This is true from the very start—synthetic oil works better when it’s brand new, and even over time. Synthetic oil tends to break down into less sludge than conventional oil, so it remains more effective over time.
It is important, however, to keep in mind that synthetic oil may need to be changed just as often as conventional oil. That time span is determined by the manufacturer of your engine, though it can sometimes be impacted by the type of oil that is used. Be sure to look at the owner’s manual for your vehicle to see how often your oil needs to be changed, and check if there is a difference listed for synthetic oil.
Emissions
All things being equal, an engine produces fewer emissions when using synthetic oil than using conventional oil. This means that if you use synthetic oil, you can feel better about your impact on air quality—and it also means you will more easily pass emissions inspections for your vehicle. That doesn’t mean that using synthetic oil suddenly makes your conventional engine on par with an electric one, but every bit helps.
When you get your oil changed at a garage or vehicle dealership, they will also filter and reuse that oil, basically recycling it. Synthetic oil can often be recycled and used more than conventional oil, so its long-term environmental impact can be better than conventional oil.
Wear and Tear on Your Engine
This is, arguably, synthetic oil’s biggest advantage—it reduces overall wear and tear on your engine during use. Since it provides more lubrication and reduces friction, it can prevent damage from heat build-up in your engine over time. This reduces wear and tear, which can save you money on service and repairs.
It’s also worth pointing out that synthetic oil can actually help an engine that has been worn down through use of conventional oil. While it’s not a miracle-worker, switching to synthetic oil can help an engine run cleaner and better. And once you use synthetic oil, you can always switch back to conventional oil without any negative side effects.
Clean Performance
All motor oil breaks down over time and develops sludge simply through use, no matter what you do. Synthetic oil, however, tends to produce less sludge over time than conventional oil, which means that it runs cleaner inside your engine. This is also one of the ways it can help repair wear and tear done to an engine through the use of conventional oil.
Synthetic oil will help reduce sludge build-ups already taking place in the engine. Additives in synthetic oil can clean deposits from the engine to help improve performance and the lifespan of the engine. Since there are fewer impurities in synthetic oil, it does not thicken as much over time, so it keeps your engine cleaner than conventional oil.
Cold-Weather Performance
If you live in sunny California or Arizona, then this is probably not a major concern for you. But anyone in a cold climate, especially those in the Midwest who deal with serious snow storms and the increasingly common polar vortex, should pay attention. Synthetic oil tends to perform better in cold weather than conventional oil does since it does not thicken as easily.
You should still let your engine warm up before you start driving anywhere when you’re in the cold. But synthetic oil helps your engine get properly lubricated quicker and runs more smoothly through your engine when it’s cold. Since it runs just as well in the heat, synthetic oil is a great all-around choice that is perfect if you like to travel and want to make sure your vehicle and engine can handle anything you throw at it.
Price
Here is where conventional oil scores a major victory when compared to synthetic oil. Synthetic oil is much more expensive than conventional oil. The price difference depends on certain factors, including the grade of the synthetic oil, whether it is full synthetic or a blend, and what additives are included. In general, however, synthetic oil is many times more expensive than conventional, sometimes as much as 10x the price.
In fairness, the use of synthetic oil can save you money in the long run thanks to better fuel economy, fewer emissions, and reduced wear and tear on your vehicle. When you’re looking at the price of synthetic oil, however, it can be easy to forget about the cost of engine work due to sludge buildup from conventional oil. If you plan on having your car for a long time, then the investment of synthetic oil is well worth it.
The Best of Both Worlds
There are two great ways to get a lot of the benefits of synthetic oil without breaking the bank. First, you can freely swap between using synthetic or conventional oil without any negative drawbacks for your vehicle. So you might use conventional oil for a year or two and then switch to synthetic for a year when you get your oil changed. In general, you should use the same type of oil when you top-off your engine, but switching between them gets you the performance and cleaning effect of synthetic oil without choosing it every time.
Second, you can choose a synthetic blend. This is not quite as good as full synthetic oil but also costs a lot less. As the name suggests, it is a combination of conventional and synthetic oil, which really does give you the best of both worlds.