Dexos, Synthetic, and Regular Oil | What’s the difference and what does my car need?


If you have ever changed your oil before then you’re familiar with the choices presented to you and – for most of us – the unfamiliarity in the choices. So – what’s the difference and what does your car need?

Dexos engine oil specification is designed by GM Powertrain engineers and is intended specifically for GM engines.  Dexos is designed to increase fuel efficiency, extend the life of the vehicles emissions system, reduce oil changes and extend the life of the vehicle. All vehicles produced in and after 2011 are stocked with Dexos oil and are recommended to be used for the life of the vehicle. Dexos can also be used in older models of GM vehicles and is a certified and licensed product of General Motors.

Synthetic oils are developed in laboratories in order to have precise strains of desirable chemicals and lubricating capabilities to ensure a higher performing oil for any vehicle. Synthetic oils are recommended by lube technicians in high mileage vehicles and vehicles that run in extreme conditions (i.e., cold weather, hot weather, elevation changes).

So what is so wrong with regular old oil? Nothing. Oil has just been improved with technology and the advancement of vehicles. Natural automotive oils have been used for years in vehicles and are naturally occurring in the environment. However, because oil is naturally occurring, there is little control over the inclusion of unwanted elements or impurities in oil. While it is a natural lubricant, these impurities also act as a source of build up over time in your vehicle’s engine. While natural oil is less expensive, it does not have the operating life of synthetic or dexos and requires your vehicle to have more frequent oil changes.

oil-change-irvine-caHelp Me Rhonda! What does Rhonda say? The first thing that you should do is check your manual and see what is recommended for your engine. If your manual recommends a higher performance oil or a specific brand, it is recommended for a reason and will help improve the life of the vehicle. Choosing the right oil will help to keep your vehicle running at its highest levels, improving gas mileage and fewer emissions. Second, stick with your initial decision. You should use the same type of oil for the life of your vehicle, and any major changes in oil decisions should be discussed with your technician. For instance, if you have reached high miles on your car or are moving to a location with a different climate, talk to your dealer or trusted technician on changes that you should make to avoid changing the viscosity of your oil. Next time you come in for an oil change – ask some questions. Find out what is in your vehicle and why – and ask your service advisor or technician if any changes should be made.

15 thoughts on “Dexos, Synthetic, and Regular Oil | What’s the difference and what does my car need?

  1. I bought my 2012 chevy avalanche[54,000 miles]at a ford garage, they had changed the oil[synthetic blend] and filter with motorcraft, with still 500 miles left before oil change was due, my oil pressure dropped to near zero. And yes the oil level was good. Changed the oil to a brand with dexos and its back between 40 and 60 psi. I will use oil w/dexos in my chevy from now on. It says dexos on the oil fill cap for a reason,

    • Thank you for you input, Randall! Yes, it is very important to use the oil recommended in your Owner’s Manual for proper operation of your vehicle. If you would like to schedule your next oil change with us, please call our service department at 248.575.5000 to make an appointment. We would love the opportunity to work with you!

  2. Which is better for my 2015 Cadillac CTS (24,000 miles)? Mobil 1 full synthetic (Dexos standard spec) or GM Dexos synthetic blend?

    • Bill,

      Thank you for reaching out! All vehicles are different. However, almost all vehicles have their required oil type printed on the oil cap. Otherwise, you can find your oil type in your owner’s manual. For any further questions, please feel free to call our service department at 248.620.3080!

      • Thanks for your reply. My previous Cadillac (2010) had Mobil 1 5W30 on the filler cap. The 2015 has Dexos 5W30 on the filler cap. Mobil1 and Delco Dexos are both made by Exxon. Mobil 1 is full synthetic while Delco Dexos is a blend of synthetic and regular oil. The cost of Mobil 1 is at least double that of Delco dexos. There are more impurities in the blend and the oil molecules are more uniform size in the Mobil 1 therefore less friction and heat. I would like to know why Delco Dexos could be any better.

      • Following factory requirements, General Motors has required the use of Dexos oil in your Cadillac. However, using Mobil 1 would be advantageous to you. Mobil 1 would be the better choice, at your discretion. By having Dexos labeled on your filler cap, General Motors is saying that your vehicle requires Dexos oil or better. Mobil 1 would fit into that “better” category. Any further inquiries, please contact our Service Manager, Jimmy Roy, at 248.620.3080.

  3. The information on your blog is really good.
    I just purchased a 2012 GMC Yukon and did the oil change myself and used the conventional 5W-30 Oil. Today I took it to a Garage to have the oil changed again and they said “We are putting dexsol in the car because it is recommended” I did not realize this when i changed my own oil that dexsol was recommended. Did I do any harm to the engine running the conventional for about 4 months. Please let me know. I am fine with running dexsol from now one I just did not know

    • Hi Jeffrey,

      Thank you for your inquiry! You did not harm your engine by switching from conventional oil to Dexos oil. The Dexos is a semi-synthetic blend that improve performance of your engine. If you have any further questions, please do not hesitate to ask!

  4. I just had to replace my “stretched” timing chain at 34000 miles on my 2010 Camaro R.S. 6cyl automatic?? Anyway the breakdown sheet says they changed oil with Dexos1 oil. Is that full synthetic or a blend?

    • Hello Phillip! We appreciate you reaching out to us. Dexos oil is fully synthetic.

      Any further questions, please feel free to call our service department at 248.620.3080.

      Thank you, again!

      • In January you replied to Jeffrey that Dexos is semi-synthetic and in March you replied to Phillip that Dexos is fully synthetic. Which is it?

      • Hello Wayne,

        Thank you for catching that! Dexos oil used to be a semi-synthetic blend. However, the formulation has changed and Dexos oil is now a fully synthetic blend.

        For any further questions or to schedule maintenance, feel free to call our service department at 248.620.3080!

        Thanks again, Wayne!

        Your Bowman Team

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