GM Powertrain has tested, validated and approved the use of 0W-20 dexos1™ as an acceptable substitute and optional top off and service fill for these vehicles. dexos1™ Information Website Refer to the following General Motors website for dexos1™ information about the different licensed brands that are currently available. Go to: dexos™1 Gen 2: 5W-30: D10107GH015: Mobil 1 SAIC-GM: ExxonMobil Oil Corp. dexos™1 Gen 2: 0W-20: D10847IF015: Mobil 1 X1: ExxonMobil Oil Corp. dexos™1 Gen 2: 5W-30: D10279HC015: Mobil 1: ExxonMobil Oil Corp. dexos™1 Gen 2: 0W-20: D10101GH015: Mobil 1: ExxonMobil Oil Corp. dexos™1 Gen 2: 0W-30: D10102GH015: Mobil 1: ExxonMobil Oil Corp Mobil Full Synthetic in 0W-20 and 5W-30 will be receiving GM Dexos1 approvals. With the current COVID-19 situation, approvals are slow coming as the testing labs are not considered "essential." So it appears Dexos 1 approval is just delayed due to the backlog at testing/certification labs. What are all of the Dexos1 High Mileage oils and which do you think is best? Valvoline Maxlife (both full synthetic and blend) and Castrol Edge High Mileage (full synthetic) are Dexos1 approved. Maxlife seems to be universally agreed to be a good product capable of stipping/reducing leaks. The Edge HM is new, does anybody have experience with it? Mobil 1 Castrol Edge (Black Jug) Valvoline Advanced All of these oils are GF-6 or GF-6a, but I recently noticed that the 5w20 viscosity is not Dexos approved. However, they are Dexos approved for 5w-30 and 0w-20. Makes me wonder why? Is 5w-20 becoming an obsolete oil viscosity? (I don't think so) Is Mobil 1 Advanced Full Synthetic Dexos approved? For drivers of diesel vehicles, Mobil 1 ESP X2 0W-20 provides the reassurance that it carries the dexosD approval for diesel engines. This unique specification has been developed by General Motors (GM) exclusively for their own diesel engines. Yes, Mobil 1 high mileage 0w20 is Dexos approved. What Oil Brands are Dexos Approved? There are a few different oil brands that are Dexos approved, but the most popular ones are Castrol, Mobil 1, and Valvoline. These oils all meet the dexos1 specification, which is a GM specific oil standard. Mobil 1 IS Dexos1 approved. Look at the label. I have indicated it with red in the picture below. To maintain your warranty without any questions or hassles, you MUST use a Dexos1-approved 5W30 oil (other than while on the track and switching to 15W50 oil). Please note: GM dexos 1 Gen 3 engine oils exceed the performance of GM dexos 1 Gen 2 engine oils and are backward compatible, therefore vehicles that previously used GM dexos 1 or GM dexos 1 Gen 2 will use a GM dexos 1 Gen 3 or GM dexos R licensed engine oil of the appropriate viscosity grade at their next oil change. #2 · Feb 28, 2018 UtahTransplant said: Just bought my first SSR, sell grinning! Local Chevy dealer uses Dexos and says it's good oil for my 2005. Is it or should I insist on Mobil 1? :| When it comes to (brands) of oil and who all likes which one, there are multiple choices and preferences. wx9KGbk.