We all have our oil brand and product manufacture choices. Which one is the best? For me I picked mine many years ago and have always used the same brand. I have never had an issue with them and always used the same brand for servicing my engine or customers engines. Are my choices the best ? I don't know! I do know I have not had a engine failure do to lubrication. I always used Pennzoil for my gas automotive engines, boat 30W, truck and car 5W30, Mercury/Quicksilver 2 stroke oil in all my 2 stroke engines, Valvoline transmission fluid ATF, and Diesel engine maintenance I used some form of Shell Rotella T3 and now the synthetic blend T4. I have not used full synthetic with my boat engines because I change the oil in a frequency that would not warrant the use of full synthetic. I no longer use Pennzoil in my car or truck only because the GM requirement is to use Dexos oil which is synthetic and my oil changes are less frequent. My car or truck are not under the same loads as boat engines.
So, where I'm I going with this? I am a user of Pennzoil, Mercury/Quicksilver 2 stoke oil, Valvoline ATF, Shell Rotella and Dexos. I have never changed and have never had a reason to change until about a year ago. Shell Rotella T4 was hard to find. The shelves were always empty. When I did find a gallon I would purchases it for the future. I do go to Costco from time to time and would see pallets of Kirkland Diesel oil available at a decent price. This made me do some research as to who makes the oil and is it any good. There is plenty of information about the company that blends the oil.Warren Distribution that makes and labels, oil for many products, Kirkland being one of them, Carquest, Meijer and AmazonBasic oils , Walmart to name a few more. From all information that I read it is a good product that meets or exceeds most engine manufactures. They also make their own brand too.
Blackstone-Labs tells me I'll find it comparable to DELO 400. I guess Blackstone would know because they test oil but wouldn't it be comparable to any oil brand with the same qualifications. The test Results and PQIA Assessment of Delo 400 and Rotella T4 are the same and I would assume the Kirkland oil would have the same results. My point is Kirkland oil is not Delo 400 but it will do the same thing. Lubricate the engine. And should be just as good. If you don't have a brand choice and you are comfortable with changing to Kirkland oil. I would not hesitate to purchase it. For me, old school thinking, I will stay with what I have used in the past. I will agree, those prices you posted are great. I paid about 17.00 a gallon and at 2.5 gallons of oil per engine X 2 the Kirkland oil would be a big savings.
