That may have been the case in the distant past, but no longer
Most of the Mobil 1 synthetic engine oil meets Dexos specs . . . but Mobil 1 full synthetic high mileage engine oil does not. Maybe that’s the one you’re thinking of.
I’m not aware of any non-GM brands that specifically require engine oil that meets Dexos specs. But maybe somebody will point it out. Various manufacturers tend to have their own specs
I had to go look. Yeah I’ve got one bottle of the high mileage for the lawn mower that is not Dexos, but all the other Mobil 1 is. Not that it makes much difference for my lawn mower but I have 5 qts that is and 5 qts that isn’t. I guess I never paid much attention to it until now. Dexos 1 and 2 though and GM 6094M?
If Dexos is such a high spec, why have I seen it on some synthetic blends? I pay no attention to the Dexos spec but my son in law asked me to order some oil for his Chevy Truck.
Volvo_v70:
If you click on Frank_Martinoli’s name to see his profile, you’ll see this is his first post.
There is a completely different account for FRANKM.
Frank Martinoli and Frankm are the same person . Apparently you can use multiple email addresses and have an account for each one.
Since we are talkin oil, And I’m as dumb as a rock when it comes to oil. I have one question. Hopefully you guys can answer me simply. Is it safe to switch from HD oil? 2 synthetic oil
Harley Davidson oil?
@Jafepf_144731. If you mean switching from Heavy Detergent (HD)oil to synthetic oil, there should be no problem if you stay with the same viscosity (e.g. 5W-20 HD to 5W -20 synthetic.
My experience in switching was with an engine on a push lawnmower. The manual called for 30 weight HD. It was using so much oil that I was leaving a trail of blue smoke. I switched it to 10W-30 synthetic and it reduced the oil consumption by 90% . I got three more seasons from the mower, and am starting the 4th season. My guess is that the mower engine may have had a stuck piston ring and the synthetic freed it up.
That would be in a static operating condition.
Where the engine operates at a constant RPM.
Transient condition is where the engine is operated thru the RPM range.
Comparing apples to oranges.
Tester
@Tester. All I was trying to say is that there is no harm in switching from regular oil to synthetic. I have no idea whether or not it would reduce oil consumption in a worn automobile engine.
I use regular HD oil in our 2003 Toyota 4Runner and it doesn’t use oil. Our 2917 Toyota Sienna and our previous 2011 Sienna soecifies full synthetic 0W-20 oil be used and so that is what I use.
I can buy 0W-20 full synthetic oil at my Rural King farm store for $2.79 that meets the specifications for my Sienna. If I weren’t so old and lazy, I would do my own oil changes and use the RK oil. When I was still working, I didn’t have time the last 20 years of my career to do my own maintenance. I thought I would have more time after I retired 9 years ago, but I got so involved in so many things I even have less time. I need a job so I can retire from retirement.
Isn’t GM 6094M an older spec . . . I want to say the older spec for 5w30, several years before Dexos 1
You can go back and forth between oils as long as they meet the engine specs.
You might want to be sure that any type multigrade oil is appropriate for your mower. My book says to use only single grade.
Thanks for the update. I wasn’t aware that I had 2 accounts.
I have no idea ho that would be. I’ll look into it. Thanks.
Perhaps you’ll get 2 IRS stimulus checks! 
Feel the magic! 
CSA
Only sensible answer is that sometimes I sign in with Facebook. That would explain the dual identities. I did check and I only have one account. FRANKM.
You may be correct on that. But GM says Dexos for all cars from 2011 onward.
This from a Google search yesterday.
Dexos engine oil specification is designed by GM Powertrain engineers and is intended specifically for GM engines. … All vehicles produced in and after 2011 are stocked with Dexos oil and are recommended to be used for the life of the vehicle .
Briggs and Stratton changed their oil recommendations several years ago for all of their small engines. So now 5-30 syn can be used year round for everything.
Good thing it says recommended. That means you don’t get a warranty claim denied for not used Dexos certified oil as long as it meets the requirements. Having Dexos on the label is shorthand so that you don’t have to look through all the pertinent requirements.