Who Makes Kirkland Motor Oil? – A Complete Overview

Written by

James Stevens

Fact-checked by

Robert A. Verdin

who makes kirkland motor oil

Is your car due for an oil change soon? You might have been used to a particular motor oil brand but have heard of Kirkland Signature Synthetic Motor Oil, which is packaged and labeled specifically for Costco.

So, who makes Kirkland motor oil? The manufacturer behind this product line is Warren Distribution.

Now, this might not be your usual brand but read on further to know why this might be worth a try for your next oil change.

Kirkland Motor Oil Manufacturer


Warren Distribution Inc. is the one who manufactures Kirkland Signature Synthetic Motor Oil and is solely distributed by Costco. Hence, it is sometimes called Costco motor oil.

Founded by James Schlott, Warren Distribution Inc used to be Warren Oil Company and has been around since 1922. Now, it is run by his grandson Robert N. Schlott.

The company is renowned as one of the leading oil manufacturers in the North Americas.

Warren Distribution oil brands come in various names, such as Warren Oil Brands, Lubriguard, Autoguard, Itasca, Coastal, and Saxon.

Kirkland Signature Synthetic Motor Oils: Getting to Know Them

Costco introduced Kirkland Signature Synthetic Motor Oil as store-brand labeled products. This motor oil product line included three synthetic motor oil types ideal for different engines: SAE 5W-30, 5W-20, and 0W-20.

These motor oils vary in oil viscosity characteristics that may or may not affect their performance once in use, following the standards set by The Society of Automotive Engineers. Hence, the letters SAE before the beginning of each type.

The numbers before the letter represents its viscosity, followed by W for winter. The numbers after the letter represents its viscosity after the engine has warmed up.

Refer to the chart below for a better understanding of SEA oil Grades:


When buying any product, especially store-brand products, consumers often think twice. Questions such as quality, the difference from known brands, and getting every penny’s worth come into mind most of the time.

It’s no different with the Kirkland Signature brand, with products labeled and marketed exclusively for Costco.

To answer these questions, let’s look into the pros and cons of Kirkland Signature Synthetic Motor Oil.


  • Protects engine from wear and tear
  • Suitable for extreme temperatures
  • Ideal for high-performance engines
  • Cheaper than most brands
  • High quality
  • Good mileage (up to 7500 miles)

These pros on the list are often what you see with most synthetic motor oil brands. Since most synthetic motor oils use higher-quality base oils, their differences would now depend on the rest of the formulation.


Since these oils are synthetic, here are some disadvantages users have noted about these products.

  • Harder on the environment
  • Causes pollution if improperly discarded
  • Costs more than conventional oils

1. Product Specifications


Like any other synthetic oil brand, Kirkland signature motor oil has undergone industry standards to ensure that it is up to the required quality in terms of specifics.

  • Kirkland synthetic oils feature zinc, boron, and phosphorus as the protection layer to avoid quick wear often caused by friction of the engine’s metal parts.
  • Silicon is among the ingredients of these synthetic oils, acting as the anti-fomaing solution to withstand extreme heat and pressure conditions, thus making the oils more efficient.
  • These products’ properties help fight interior engine damage due to a sludge buildup that tends to damage an engine over time and wear and tear. Due to its refined synthetic oil base, its molecules work efficiently to ensure your engines are protected from damage while maximizing their potential.
  • Kirkland synthetic oils also have good thermal regulation due to their viscosity that helps withstands extreme temperatures, protecting your engines from overheating and releasing exhaust emissions.

2. Synthetic Oil Manufacturing

Synthetic oils are made mostly from chemically formulated bases such as petroleum and crude oil. In other cases, these oils are made from raw materials through synthesizing.

They are the alternatives for petroleum-refined oils due to the formula’s ability to withstand high heat and pressure.

3. Product Costs


  • Costco sells Kirkland Signature 5W-30 full synthetic motor oil at $79.99 for a 4-pack of 5-quart bottles.
  • The same price applies to the SAE 0W-20 variant of the same quantity.
  • Meanwhile, they sell the SAE 5W-20 variant at $49.99 for a 12-pack of 1-quart bottles.
  • Another product sold under the Kirkland Signature label is the Kirkland Heavy Duty Diesel Oil SAE 15W40, intended for diesel-powered motors.

The price, however, varies depending on which state you are buying from.

Kirkland Signature Synthetic Motor Oil vs. Mobil 1: What’s the Difference?


Mobil 1 and Kirkland engine oils are both categorized as synthetic oils. The difference, however, lies in the formulation, as Mobil 1 carries its name and formulation from its brand manufactured by Mobil, now known internationally as ExxonMobil.

As per cost, although both use synthetic base oils, Mobil 1 cost significantly higher than Kirkland Signature at $26.97 per 5-quart bottle and $89.91 for a 3-pack of the 5-quart bottles.

Mobil 1’s 3-pack price alone already costs $9.92 more than Kirkland’s 4-pack of 5 quarts.

In terms of performance, Kirkland Signature may be at par with Mobil 1, given that both products follow the same industry standards. It all boils down to your needs, preferences, and budget.

Why Knowing the Manufacturer is Important

Knowing who produces the oils can help track the company’s reputation, history, and technology. It’s also helpful to receive customer service regarding any problems with warranties and oil quality.

Furthermore, a trusted brand can ensure long-term protection for the car engines, reducing the vehicle maintenance and repair work.

Frequently Asked Questions


Is Kirkland motor oil synthetic or conventional?

Kirkland Signature Synthetic Motor Oil is a synthetic type of oil. It comes in three variants with varying viscosity grades. These oils are the best choices for extreme operating temperatures.

How often should I change my oil if I use Kirkland motor oil?

A good rule of thumb to remember when using synthetic motor oil is to replace it after 12 months or about 5000 – 7500 miles.

Can I use Kirkland motor oil in any type of engine?

Kirkland motor oil is suitable for most high-powered engines. However, it is best to consult your engine’s user manual to see which motor oil is designed and appropriate for your engine type.

Does Kirkland motor oil expire?

Like any product, motor oils also tend to “expire” and lose their efficacy when stored and unused for a long time. The components used to make the synthetic oil tend to break down after being stored for too long. Most motor oils lose their efficacy if not used for five years.


Knowing who makes Kirkland motor oil makes a big difference in your buying experience as a consumer. With Costco’s Kirkland Signature Synthetic Motor Oil, we know what company makes it, one that’s trustworthy and has been around for over 90 years.

It might be a store-brand name known throughout for its various products, but knowing who makes the motor oil you’re about to buy puts you at ease with the quality. Try it on your next motor oil change!

5/5 - (2 votes)

James Stevens

James Stevens is an expert bike mechanic who knows everything from basic repairs to custom modifications. What sets him apart is his ability to explain complex concepts in a way that's easy to understand. Check out his content on Speedway if you need help with upgrades or modifications for your bike.