We Accept
Established 2007
Kelly Poynor
(509) 554-3856
4227 Galway Lane
Pasco, WA. 99301



Compairing The Top Brands In Todays Market

Thank you for taking the time to read my blog about three motor oils and what someone should look for when comparing Poynor’s Motor Supplies/AMSOIL, Royal Purple, and Mobil 1 brands. Without getting over technical on the synthetic oil chemical compositions, additives, and other aspects, synthetic oils have about them. I have been doing some research and compared Royal Purple, Mobil1, and AMSOIL.  

Top Three Factors When Buying Motor Oils

These mostly can be broken down to only a few critical factors to consider.  These include viscosity grades, oil change intervals, and price. Viscosity GradeThere are a lot of “experts” out there who claim this and claim that but one crucial factor to consider when picking an oil for your engine is the viscosity grade.  In my opinion and based on a ton of reading, the leading brands of synthetic oil on the market are, in all practicality, identical. I highly recommend basing your viscosity grade you choose for your vehicle is the one your vehicle owner's manual says to use. The manufacturer's design motors to run their best with these specific viscosities in mind.  

Here are some of the most common engine oil grades: 










By using a synthetic engine oil with the wrong viscosity can or could cause premature or excessive engine wear and tear on the internal components (ie: camshafts, crankshafts, valve springs, valves, rocker arms, lifters, etc. etc.), which can also lead to lower gas mileage and potential damage to your engine. 

Before You Buy Make Sure You Know What You Need

So before you head to your local independent dealer, auto parts store or internet site to order and buy 5, 6 or 7 quarts of oil, check your owner’s manual to see which viscosity your vehicle manufacturer recommends. Change Interval The next factor to consider when comparing AMSOIL, Royal Purple and Mobil 1 is the change interval. For the longest time, conventional motor oils you needed to change every three months/3,000 miles, whichever came first. 

You Are Spending To Much Money Per Year If Your Not Using AMSOIL Signature Series

These days vehicle manufacturers are now recommending car owners to change their engine oil every 5,000 to 7,500 miles. Now that synthetic oils have a much longer lifespan. Scientist and engineers have proven that synthetics oils can last up to one year without being changed. If you are like me and many others Kelly Poynor and I work with and don’t like changing your oil all the time or forking over and paying $60 to $80 every few months, a synthetic oil with a lot longer change interval you should strongly consider.  

Blogger’s side note:  With more extended change intervals reduces the amount of waste and reduces the need for extracting additional fossil fuels to make the product. Keep in mind the recommended change interval does vary and is based on your driving habits.  Most synthetic oil companies typically divide most individuals driving habits into a few categories. In this article,  we will only look at the two of the most common: regular service an severe service. For instance, AMSOIL defines regular service as “personal vehicles frequently traveling greater than 10 miles at a time and not operating under severe service.” Moreover, most define severe service as “turbo/supercharged engines; commercial or fleet vehicles; excessive idling; daily short-trip driving less than 10 miles; frequent towing, plowing or hauling; dusty-driving conditions.” 

Driving The Extra Miles With AMSOIL

As a safety measure, if your vehicle meets any of the severe service criteria, your vehicle may not qualify for the extended change interval. I would recommend you should change your oil more frequently to prevent possible damage to your engine. So here is how the change intervals of AMSOIL, Royal Purple and Mobil 1 compare? 


AMSOIL Signature Series Synthetic Oil – 25,000 miles / 1 Year  for Normal Service and 15,000 miles / 1 Year for Severe Service 

Royal Purple Synthetic – 12,000 miles / 1 Year for Normal Service and 12,000 miles / 1 Year for Severe Service 

Mobil 1 Extended Performance - 15,000 miles / 1 Year for Normal Service and Severe Service

What Are You Paying Per Quart

Look and check out the Owner’s Manual. Now we will get the final factor when considering and when comparing AMSOIL, Royal Purple, and Mobil 1 is the price per quart. Using synthetic is going to be more expensive than conventional oil. However, as Kelly and I pointed out, the interval between oil changes is a lot longer. Just upgrading your oil changes to a synthetic lubricant can save you money depending on your driving style and how often you had changed your oil previously.  In this article, prices mentioned I had located online during my research for this article. 

Current costs may be different. Keep in mind that prices at local auto parts stores may be a touch higher than those found online but buying local is also pretty significant as it supports your community. It is also common for prices to differ depending on your location and current sales or promotions.  

When I decided to pick a synthetic oil, I compared the price of what I actually would use in my 2007 Chevrolet Monte Carlo SS which has the 5.3 liter V8. The owner manual stated that a 5W-30 oil to be used. So here are those numbers. 

AMSOIL Signature Series Synthetic  5W-30 --$12.40/qt.

Royal Purple High-Performance Synthetic 5W-30--$13.58/qt.

Mobil 1 Extended Performance 5W-30--$7.88/qt. 

Blogger’s Note: AMSOIL Preferred Customers can receive up to 25% off retail prices when they sign up to join the program. After the likely 25% off discount, the cost will reduce to $9.30 per quart of oil. 

We Are Just About Done!

ConclusionToday, the leading brands of synthetic oil, including AMSOIL, Royal Purple, and Mobil 1 are almost identical. Since these brands are all API certified, you can be relatively confident that they all meet or exceed industry performance requirements. However, when it comes time to decide between all of these options on the market, review the three things to consider. Viscosity Grade, Drain Intervals, and Price. 

As we mentioned, the most critical factor when selecting an oil is buying the correct viscosity grade. If you have any questions, give Kelly or I a call directly or refer to your owner’s manual to find out which viscosity your vehicle requires. The other and equally important factors to consider is the drain interval and price. In our research, we discovered that AMSOIL has the longest drain interval at 25,000-miles. Royal Purple has a 12,000-mile interval, and Mobil 1 Extended Performance is 15,000-miles. With these factors in mind, it is up to you to decide which oil is right for your car or truck. 

Times Have Changed, It's Time To Consider Protecting Your Vehicle

Some people are very brand loyal while others are always looking for the best deal, everyone should be looking for the best protection for their vehicle. When everything considered and a holistic approach (drain intervals, product costs, waste and disposal, environmental impact and so on) is considered, AMSOIL appears to come out on top nearly every time. 

Thank you for taking the time in reading this blog. If you have any questions, please don’t hesitate in giving one of us at Poynor’s Motor Supplies a call. We can be reached directly at the following numbers: Kelly Poynor (509-554-3856) or me (John Poynor – 509-539-3928). We will make a sincere, concerted effort to answer any question you may have.  We look forward to hearing from you soon.


 (509) 554-3856

 4227 Galway Lane
Pasco, WA, 99301
United States
All trademarks are the property of their respective owners and may be registered marks in some countries. There is no affiliation or endorsement claim, express or implied, made by their use. AMSOIL products are formulated to meet or exceed the performance requirements set forth by the manufacturers of all applications shown here.
© AMSOIL INC. 2021  |  www.amsoil.com