What is the best synthetic oil for my vehicle?

I just bought a used 2004 Yukon Denali. I want it to last and will be pulling a pop up trailer, travel trailer etc. What is the best synthetic oil that I can get from like Valvoline instant oil change stores? Or others like Jiffy Lube, etc. Just want to find the highest quality oil that will last. Thanks.What is the best synthetic oil for my vehicle?
It depends who you ask. Some are more than happy with conventional oil and some say go for synthetic oil. I've researched synthetic oil and from what I can find, Mobile 1 and AMSOIL are the only two true synthetics sold. I've chosen to use Mobile 1 in our SUV because I think it is better than conventional oil but that's me. I've also looked at oil filters and will stay away from FRAM. I've been buying Mobile 1 extended filters but I will go to Purolator Pure One filters based on my findings and it also costs less but seem to be made just as well as Mobile 1 extended oil filter.



You might want to look into transmission coolers since you will be hauling trailers, they're not expensive and could save you in the long run.



Hopefully the previous owner(s) stayed on top of the maintenance schedule, that is probably the biggest factor on the longevity of your new vehicle.
Our daughter has an 04 Tahoe with the 366 cubic inch engine. She and her husband pull a 4,800 Mastercraft boat and trailer 1,888 miles each summer. She's used Mobil1 for the following reasons: The oil viscosity for this truck is 5W-30, it pours @ -48 degrees below 0 Farenheit. In other words the oil pump is able to force a greater volume of oil to critical frictional surfaces quicker during start-up. Cold starts is where 80% of all engine wear occors. I suppose other full synthetics are fine but none of them publish their full physical properties disclosier as does Mobil1. As for myself, I've got to see it and read the facts not opinions.



If I were in your shoes I'd have the oil changed at your local GMC or Chevrolet dealership. You can save a few bucks by carrying in your own Mobil1 that you purchased at Walmart.What is the best synthetic oil for my vehicle?
Stay away from Jiffy Lube. They tell you they are using a synthetic but instead they use there conventional oil.

I personally use Castrol. Its best for high or hot weather conditions. If your pulling a trailer then use a lower weight, so the oil will travel faster. You also want to get the high mileage oil filter too. But the mother of them all is MOBIL 1.

If you buy the oil personaly you can take it to any WAL-MART or SEARS and they will add that one.
The best synthetic oil for the GMC 6.0L V8 engine in your Denali is Quaker State Q Torque Power motor oil.What is the best synthetic oil for my vehicle?
They are all similar and it all boils down to preference really.
Valvoline Max Life is a good oil
Mobile 1 or Royal Purple and you really can't go wrong with Amzoil.