What Does Dexos Mean In Motor Oil?

If you don't typically perform your own vehicle maintenance, you may not be familiar with the classifications of motor oil and what sets them apart. You might also not know that Dexos isn't a type of oil, but a performance specification developed by General Motors. Oils that carry the official Dexos seal have gone through GM's certification process.

The certification process itself combines industry motor oil standards with additional testing requirements created by GM. The end result is products that meet the company's expectations for both performance and engine protection, and so, oils with the Dexos mark go a step further than the broad requirements of other oils used across the industry.

The Dexos specification has received its fair share of updates since its introduction in 2011. For example, Dexos1 Gen 3 was introduced as an improvement over Dexos1 Gen 2, and it can be used in vehicles that previously required earlier Dexos1 specifications. Dexos D replaced Dexos2 for certain light-duty diesel engines, and Dexos R is meant for newer gasoline engines. As these specifications continue to change, vehicle owners should always follow the manufacturer's oil recommendations listed in their owner's manual.

Even though Dexos was developed by GM, that does not mean it can't also be used in other vehicles. Other manufacturers could allow the use of Dexos-approved oil if it meets the specifications required for their engines. However, drivers should not assume that any Dexos product will work in just any vehicle. This is why, once again, the owner's manual should always be used as the guide for choosing the correct oil type, as well as viscosity.

When it comes to the lifespan of dexos-approved motor oils, GM does not list a specific service interval that applies to every vehicle. This means there is no universal answer for whether dexos oils will last longer than other types of oil. Oil change schedules depend on various factors, including engine and driving condition, as well as the manufacturer's recommendations, but GM has designed its Dexos specifications to give oils resistance to breakdown, as well as better engine protection over the life of the oil.

Some drivers assume that Dexos oils are typically more expensive than other options, but the certification alone does not automatically determine the price. For example, a quart of Castrol Edge High Mileage Full Synthetic 5W-30 without the Dexos certification retails for $12.99 at AutoZone. In contrast, a quart of Castrol GTX Standard Full Synthetic 5W-30 that is Dexos1-approved costs $7.00 at AutoZone. While searching for different grades of oil could yield different results, it's always best to look at the details before making a decision to purchase.