Which synthetic oil to use

Synthetic tends to stand the test of time much better than conventional oil. Each oil brand closely guards their proprietary chemical formulas as a trade secret, with promises to protect longer, better and across a wider range of environmental conditions.

That said, many manufacturers specify a recommended brand and viscosity, typically called the oil weight. We chose five outstanding engine oils known to deliver reliable protection at a great price. Each is suited for a specific application.

As synthetic motor oils go, Mobil 1 is the industry benchmark. Well-regarded for its detergent qualities, Mobil 1 has been the factory-fill choice for high-performance engines for decades.

The Extended Performance formulation is designed to protect for up to 20, miles under optimal driving conditions. When ordering, look for the DexOS symbol on the front of the bottle to verify the oil meets this standard.

We only recommend DexOS-rated oils. As the cost of synthetic oil drops closer to conventional oil, remember that some engines are still better suited to conventional oils. Older vehicles or engines that have run on conventional oil for hundreds of thousands of miles may need the specific additives included in conventional oils to prevent leaking seals.

Rotary engines in particular require conventional oil, and Mazda specifically recommends against using synthetic oil in models like the RX-7 and RX Castrol GTX is a high-quality conventional oil that helps keep older engines healthy and, when it does enter the combustion chamber because of worn rings or seals, burns fairly cleanly, protecting spark plugs from premature fouling.

Extended heat cycles, longer service intervals and the sheer expense of a diesel oil change make it important to choose a high-quality oil. Sometimes, you just need to get home. Synthetic blend oils deliver more consistent viscosity changes in response to temperature variations than conventional oil, suiting them to climates with moderate temperature swings. Provides 1. Dramatically reduce engine wear Leave critical engine parts 4X smoother.

We specifically chose highly-rated and readily available motor oils that are compatible with a wide range of vehicle makes and models on the road today. Forbes Wheels considered the products that are the most accessible to consumers residing throughout the U. If your car only calls for conventional oil, the slightly higher cost of a semi-synthetic product will provide better engine protection. Regardless of the oil used, always follow the vehicle manufacturers' recommended oil change intervals," says Calkins.

Additionally, think about how long you plan to own your car. Investing in premium lubrication may slightly extend the life of your engine; However, if you are planning to sell your car long before engine failure is likely with mineral oil, the benefit of using expensive synthetics is transferred to the next owner of your car. In other words, you paid for expensive oil but gained minimal benefit during the time you owned the car.

It should be said there are certain exceptions to this concept. One in particular is exposing an engine to worst case scenarios long before their normal end of life. Worst case scenarios include extreme temperatures, forgetting to change the oil on schedule, heavy loads, frequent cold starts, frequent short commutes, impaired engine cooling, etc.

Synthetic oil used in motor vehicles is refined from base oils or base stock oils. The American Petroleum Institute API categorizes base oils into five categories; the first three are oils refined from petroleum crude oil. Group IV base oils are fully synthetic, and Group V contains all base oils not in the first four groups.

As mentioned, extreme conditions and worst-case scenarios demand the use of synthetics. Because they are so expensive, if you use them, insist on getting value and performance in return.

Below are the passenger car applications that are ideally suited for synthetics motor oils:. There are a few instances when the right decision on whether to use a synthetic motor oil is far more unclear - or simply just a close call.

In such cases, your only tactic is to use good judgment and carefully consider all facts and circumstances. For instance, the jury is still out on the value, if any, that is gained in fuel economy by using synthetic motor oils.

As mentioned previously, the opposite may be true. We encourage you to read our updated Privacy Policy Hide. Toggle navigation Toggle search. Magazine Subscribe Today! Current Issue Archive Advertise. What Is Synthetic Oil? Synthetic vs. Advantages and Disadvantages of Synthetic Oil So, what are the advantages of switching to a synthetic as opposed to a conventional motor oil?

When exposed to certain conditions, conventional mineral oils are usually more prone to chemical degradation oxidation compared to synthetics. These harmful conditions include combustion byproducts, fuel contamination, water contamination, metal particles, acids, pro-oxidants and extreme heat e. Exposure to these conditions commonly occur in engines. Oil degradation can cause sludge, varnish or deposits, corrosion, viscosity change and impaired engine performance.

Synthetics have a naturally higher viscosity index. This means the viscosity changes less more stable as temperature changes during normal engine startup and operating conditions. Viscosity is an important property of lubricants that produces the film thickness or clearance between metal surfaces that slide or rotate against each other.

Without this film thickness, excessive friction and wear would occur. Getting an oil change can feel mundane, but swapping out the goop in your engine ensures performance down the line. Although you can use conventional oil, the best synthetic oils can bolster your engine and keep it running smoothly.

But how can you tell which one is the right choice for your car? This in-depth review will look at some of the best synthetic motor oils on the market based on the benefits they offer your engine. Having additives that keep oil from breaking down and provide strong sludge and deposit protection also helped it earn the top spot. It also works in cars ranging from daily drivers and high-performance cars to trucks and vehicles with diesel engines. Customers like the durability and price point of the product, but a few reviews mention the oil burning quickly.

Drivers looking for full synthetic oil that offers performance at an affordable price should check out the Castrol GTX Magnatec series, which we awarded the title of Best Budget Oil. Castrol says it offers six times better protection than industry standards, citing the Sequence IVA Test that measures common engine wear. Along with the budget-friendly price point, this full synthetic oil clings to critical engine parts throughout the entirety of the drive cycle, helping reduce the amount of wear that happens during idling and stop-and-go driving.

The overall value and quality appeal to buyers, but some mention the oil being thicker than anticipated at lower temperatures. Diesel owners looking for synthetic engine oil may find the Shell Rotella T6 formula a winner. This offering from the Netherlands-based company promises a 1. Additives in the Rotella cocktail help protect against soot, dirt, and other debris, and the oil has improved wear protection from the previous generation of diesel engine lubricants.

A Honda spokeswoman said the automaker uses a synthetic oil in the Civic for its low viscosity—meaning it flows more easily than oils with higher viscosity—which helps to improve the engine's fuel efficiency. The faster the oil flows, the quicker the engine parts can turn.

Honda is not alone, says Mel Yu, auto analyst at Consumer Reports. In the model year, about 70 percent of new cars get either fully synthetic or blended oil. Several brands, including Honda, don't specifically require synthetics for their engines, but the low-viscosity oils that those engines need are offered only in a synthetic format, Yu says.

On top of that, many oil-change outlets also offer synthetic oil as an alternative to conventional engine oil. According to Will Hixson, spokesman for the Automotive Oil Change Association, the National Oil and Lube News annual survey shows that more than half of car owners are choosing synthetics or synthetic blends when they get their oil changed.

Synthetics have some advantages over conventional motor oil.