i would go with synthetic no matter what. theyre engineered to lubricate better and outlast conventional oil. the extra price you pay when you buy them is worth the extra protection and longevity that they provide.
So I guess majority would recommend synthetic. I guess for the extra money it will cost me in the long run its worth investing that into the car.
They put a lot of time into doing research on whats the best for it so why not follow their recommendation.
You don't have a choice if yours is a 2011 or newer. You have to run a synthetic blend that meets the dexos requirement. So now you get to pay more for motor oil.
I know the thread is a bit old but to me, it doesn't matter whether you use regular or synthetic. The most important thing is the oil change interval.
First of all te manufacture recommendation isn't "what's best for the vehicle" it's the requirement level that should stay at or higher.
The only engine that I know that benefits from NOT using synthetic oil is a rotary engine. Convential oil is the only thing a rotary engine can run without long term damage.
Almost every car on the market comes from the factory with a synthetic blend or synthetic. Convential oil is almost completely done and it had nothing to do with charging you "more money."
In order to meet today's fuel standards manufacturs have to have a set mpg across the board that there vehicles make combined. This was the number one reason Nissan switched to synthetic 0-20 oils in almost every vehicle they sell. The oil creates less friction. They might only see a 1-2mpg difference on the hwy, done in multiple models it raises their average.
Overall though syntheic oils are better, the amount of research that oil companies put into developing their oils outweighs the awm mount of research car companies put into selecting a recommendation.
In my terrain I use the recommended weight but I use full synthetic. But remember once you go full you don't go back.
Now oil changer intervals is a large gray area. Mobil 1 and other companies stamp a number on how many miles there oil can go. Car manufacturs set a interval standard used to prevent engine failure in worst case scenerio. Most car companies used to say 3000 miles. With new technology and oil most are far from 3k miles. There are cars on the road today that recommend 12k oil changes. Some people won't agree, but guess what? If it was that bad for your engine car manufactures wouldn't have set such a high interval specially because of warranty.
Also think of the oil life percentage are vehicles have. How many cars have you seen at 3000 miles said less then 10% oil life? Most of my GM vehicles where over 50% at 3000. With today's technology the pcm is suppose to calculate how long your oil will really last based off your driving habits compared to formulas predetermined and programmed into your vehicles.
Speaking from years of experience;
I have always used Castrol in every one of my vehicles and I've been driving for over 40 years.
I wait for the first 1000 miles to go by on my new engines and then drain it and replace the filter too..I then put in Castrol Edge Syntec (correct weight) and then change it every 5000 miles there after...never had a single engine problem in any of the engines I've used it in..to include; Mercedes 190E, 300E, Toyotas, Celicas and Supras, Mazda RX7, Nissans 240Z and 280Z, Hummer H3, Jaguars X-type, XF and they only recommend Castrol, and now this new GMC, I plan to do the same..
PS..I also use only WIX oil filters.
This may seem ridiculous, but I feel so strongly about my previous post, I may forego the dealerships 4 free oil changes. Which I found out at closing today that GM is giving them to me..maybe I'll just take them the oil to use.
I forgot to add....
Whatever you use, make sure it is the correct weight and has the DEXOS
I get free lifetime oil changes from the dealer I bought it at. I did ask them what type of oil they use and which increament to follow. The service tech said they use a speciality GM synthetic blend that the factory uses. and to go by milage and not the oil life indicator. i do mine every 5000 miles.