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Testing Costco's Kirkland Full Synthetic Motor Oil

This video compares the performance of Costco’s new motor oil with that of Walmart’s Supertech oil.

If you don’t want to watch the entire video, I will summarize the findings for you:
The Kirkland oil performed essentially the same as the Walmart oil and Amazon’s Basic oil–and that means very good performance.

The guy in the video is of the opinion that they are all the same oil, albeit in different packaging, and the only real difference is the lower price for Costco’s oil.

Oils formulated to the same API standards should perform the same. The qualifying tests are rigorous and should result in the same overall performance.

Where some oils differ is in the amount of performance additives in addition to the basic API specs.

Does that. Include the Costco membership?

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My local Rural King farm store has Harvest King full synthetic at $2.79 a quart. It used to be branded as RK oil. It comes in 0W-20, 5W-30 and 10W-30 viscosities. The RK brand 0W-20 met the specifications for the 2011 Toyota Sienna I owned at the time. I bought a quart to keep in the van in case I had to add a quart between changes. I never had to use the quart, so I now keep in in my 2017 Sienna for the same purpose.
If I still did my own oil changes, I wouldn’t.hesitate to use a house brand oil from Rural King, Costco, or Walmart that met the specifications for my vehicles.
Back in the days of regular motor oil, I was of the opinion to stick with a particular brand. However, I once found a special for Citgo oil with a mail-in rebate which made the oil free except for the price of the postage stamp. I couldn’t resist the bargain and the Citgo did as well as the oil I had been using. From then on, I purchased whatever oil was on sale that met the specifications for my vehicles.
Some years back, Consumer Reports did an extensive test on motor oils. The same brand and viscosity of oil was different in different regions of the U.S. I would bet that the same refinery bottles the same oil under different brand names which reduces shipping costs.

The kirkland signature synthetic engine oil is distributed by Warren . . . it says so at the very bottom of the carton

Do you happen to know if the super tech is also distributed by Warren . . . ?

Kirkland, Supertech, Amazon, are all distributed by Warren.

So is Pronto, MAG 1, and a few other house brand oils.


Thanks for the information :+1:

Warren supplies a lot of the stuff on the shelves of our fleet’s warehouses

The Warren Oil Co. lists 13 brand names they provide oil under. There could also be private labor products they supply that aren’t listed.

I use Mobil-1 Extended Performance just because I try and err on the high side, the overkill side, but I think that all oil is good if it meets or exceeds manufacturers’ specs and viscosity parameters.

I do feel that synthetic oils flow better at very cold temperatures and perhaps offer more protection at very high temperatures.

All that aside, I think motor oil is a lot like coffee and beer…

…It’s all good and some is possibly better than others, the best coffee and beer is the free stuff in a full mug or glass…

…and the best oil is the oil that is clean and changed in a timely manner and up to the “full” mark on the dipstick!
:palm_tree: :sunglasses: :palm_tree:

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The best oil is the one that meets ALL the specs, viscosities, certifications, etc. for a particular engine

Translation . . . the best oil is the correct oil for your engine

no ifs ands or buts


Project Farm (the youtuber whose video is posted above) has done lots of oil tests. He has also done comparisons of air filters, wiper blades, car batteries, oil additive products, etc. The list of his videos can be found here.

Hi there fanboy! I guess that you missed something I said, once again! :grin: It was just above where you took my remarks out of context…

That carefully worded explanation came first.
But keep reading my stuff, misconstruing the information, taking things out of context, and pouncing on my every statement.

I appreciate you awaiting every remark I make. One can never have enough admirers! Thank You db! :wink:

:palm_tree: :sunglasses: :palm_tree:

I very carefully read what you said

At first you were on the right track by mentioning the viscosities and specs

But then you blew it when you said the best oil was the one that was clean, changed in a timely manner and up to the “full” mark on the dipstick

you have only yourself to blame

And don’t insult me by calling me “fan boy”

We both know that’s nowhere near the truth of things

I actually enjoy this back and forth

But if you want to continue believing that you’ve got all these admirerers . . … well, I guess everybody’s entitled to their opinions

But sometimes opinions aren’t the same thing as facts . . . :thinking:


Hello, and I hope you are enjoying your weekends. Let’s take a step back and if there’s a disagreement or feedback to be given, focus on the statements made, without any name calling (“fanboy”) or character judgments. It read to my eye like csa did say he followed specs for his oils.

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Any thinking, reasonable person with basic comprehension skills, and especially anybody who’s read my stuff here for a while (and knows I can keep cars going “forever”, with little effort) would realize that I was not in error…

…“Any thinking, reasonable person…”
Oh, wait! I can see where you got confused, but that’s okay! You’re certainly welcome to keep reading and enjoying or if that 's problematic, you can just ignore my responses anywhere on this site, if you’d like. It’s good to have somebody who cares so much, though. You are definitely my most avid reader. :grin:
:palm_tree: :sunglasses: :palm_tree:


I’m not laughing with you

I might agree with that

I really don’t understand what that has to do with anything

There’s lots of people who do that who don’t get any admiration from me . . . hint hint :wink:

Have you been to a dentist lately? I wouldn’t be laughing either if my teeth were like that.
:palm_tree::sunglasses: :palm_tree:


Now you folks should just be thankful for the blessings that you have. Me? I went to youtube for Easter church services with all our pastors banned to their homes. Not bad considering. Of course the radio had re-runs of 2019 services. Then just like last year on Friday, April the 13th, we are getting about 4 inches of snow, but I already put the snow blower to bed for the season. So no going out to get take-out Easter dinner, so I saved about $70 from the normal Easter Brunch. Luckily I bought a ham just in case and the wife seems to know what to do with it. It was the first ham I ever bought in my 70 years. So cheers and try to be nice to each other, especially if you’ve got temps above 50 degrees. And on the other hand, there will be no car problems if the cars just sit in the garage. So who is complaining?

I might try out that Kirkland Signature engine oil some day . . . the 0w20 meets all the specs for my mom’s Honda, and the 5w30 meets all the specs for our Toyotas

the 5qt carton is somewhat of a turn-off

But I’ve got quite a bit of Mobil 1 still in my garage, and I’ll use that up first

Based on the price, I’ll assume the costco oil is base 3 . . . ?!