AMSOIL vs Red Line: Which is Best?

When it comes to full synthetic racing motor oil brands, AMSOIL and Red Line are two companies that definitely come to mind first. During my time with AMSOIL, I’ve had many customers inquire about how AMSOIL compares to Red Line, reviewed technical specifications and made technical and product recommendations to potential and existing customers.

Typically customers purchase products and do their own testing/evaluation and when they experience noticeable differences they make the switch to AMSOIL. For example, one of my long-time accounts is a performance automotive gearbox manufacturer that contacted me seeking an alternative to Red Line 75W-90 Gear Lube and after testing AMSOIL 75W-90 Manual Transmission and Transaxle Gear Lube they made the change.

As we'll discuss in this article, Red Line and AMSOIL are both very high-quality synthetic oil companies that make some of the best engine oils and other synthetic lubricants on the market.

Overview of Red Line & AMSOIL

AMSOIL and Red Line are both significant players in the synthetic lubricants industry that share some commonalities, but they have distinct histories and characteristics that set them apart, particularly in their founding principles and development approaches.

Company Origins

Red Line Oil was established in 1979 in Benicia, California, by Tim Kerrigan and Roy Howell. Their backgrounds in chemistry and racing led them to develop high-performance synthetic lubricants using advanced ester-based formulations. They focused on creating products that would meet the extreme demands of racing applications, which then translated into high-performance street applications.

AMSOIL was founded in 1968 by Al Amatuzio - a former jet fighter squadron commander, in Superior, Wisconsin. His background in aviation inspired him to research, test, and develop his own synthetic oils for automotive use. Synthetics were used exclusively in jet engines at the time and he was certain synthetics would also be a great choice for the automotive industry.

Innovation

Red Line distinguished itself by being one of the first companies to extensively use polyol ester base stocks in their formulations - a more expensive but highly effective synthetic base oil typically reserved for aerospace applications. This commitment to using premium base stocks set them apart in the industry, particularly in racing applications where their products gained a strong following for their superior high-temperature stability and wear protection.

AMSOIL's early claim to fame was pioneering the first full synthetic motor oil to meet API service requirements (AMSOIL's 10W-40 Synthetic Motor Oil) in 1972. In the many years leading up to that breakthrough, Amatuzio had been constantly researching synthetic oils and asked one of his fellow fighter pilots to try his formulation in his own vehicle. At that time, motor oil quality was extremely poor and engines didn't last very long. Oils were constantly breaking down in high-temperature conditions and made it much more difficult for engines to start in cold weather. This breakthrough signaled a new era in lubrication science, and many big oil companies would soon follow-suit with their own full synthetic engine oils.

Products & Marketing

Both companies offer a fairly wide range of synthetic lubricants and additives, including transmission fluids, gear oils, suspensions fluids, and much more.

Red Line focuses on a more specialized product line, primarily catering to high-performance and racing applications. Their product range includes motor oils, gear oils, transmission fluids, and specialty lubricants, with a particular emphasis on products for European and racing vehicles. They're especially known for their Manual Transmission (MT) fluids and Water Wetter cooling system additive.

AMSOIL primarily specializes in full synthetic lubricants for an extremely wide range of applications, including automotive, powersports, racing, motorcycles, ATVs/UTVs, snowmobiles, heavy-duty trucks, diesels, and commercial vehicles, RV's, marine, small engines, classic/vintage vehicles, and several more industrial and commercial applications lubricating air compressors, bearings, turbines, gearboxes, and many more.

Red Line utilizes a more traditional distribution model, selling through performance automotive retailers, speed shops, and specialty racing outlets. While their products can be found in some larger auto parts stores, they maintain a focus on the performance and racing market segments rather than mass-market retail.

AMSOIL primarily relies on a network of independent dealers for distribution, paying commissions on sales, as well as retailers that carry AMSOIL Products. They also heavily market and advertise their own products and have secured many strategic partnerships with aftermarket engineering companies, racing series', and race teams, while also partnering with thousands of automotive and powersports service centers, oil change shops, and commercial businesses through their AMSOIL Installer, Retail, and Commercial Account business opportunities. AMSOIL keeps most of their products out of big-box stores to maintain a competitive advantage and to help support value-adding service business that offer specialized products and services.

Ownership

AMSOIL has been family owned and operated since their inception. Currently, the founder's son, Alan Amatuzio, serves as Chairman and CEO.

Red Line Oil was acquired by Phillips 66 in 2016, becoming part of their specialty products division while maintaining their distinct brand identity and commitment to high-performance lubricants.

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Red Line vs AMSOIL Matchup

Both synthetic oil brands produce a wide variety of lubricants and additives for many similar applications, so we'll be directly comparing oils of similar viscosities and additives for similar applications to see which bolster the best technical specifications and performance test results.

AMSOIL Signature Series vs Red Line Oil High Performance

In this first matchup, we'll take the best of the best full synthetics for passenger vehicles from both AMSOIL and Red Line to see how they compare across technical specifications and approvals. AMSOIL Signature Series and Red Line High Performance both meet or exceed similar specifications & approvals but there are some notable differences:

Specifications & Approvals

API & ILSAC Standards:

• Both oils meet current API SP (including Resource Conserving) and SN PLUS standards
• Both oils meet current ILSAC GF-6A requirements, which is the latest standard for passenger car motor oils

OEM Approvals Breakdown:

• Both oils meet GM's latest dexos1 Gen 3 specification
  • This is important because dexos1 Gen 3 actually supersedes several older GM specifications that Red Line lists separately (including GM LL-A-025, 6094M, and 4718M)
  • When an oil meets dexos1 Gen 3, it automatically covers these legacy specifications

European Specifications:

• AMSOIL lists ACEA A5/B5 and A1/B1 certifications
• Red Line lists specific approvals for several European manufacturers:
  • BMW LL-98 (older specification)
  • VW/Audi 502.00-97, 503.01-99
  • Mercedes-Benz specifications (MB 229.3, MB 229.1)
• Important to note here that both oil companies make European-specific engine oils so we'll compare those later on

Ford Specifications:

• AMSOIL lists newer Ford specifications (WSS-M2C946-B1, WSS-M2C946-A, WSS-M2C929-A, WSS-M2C961-A1)
• Red Line lists several Ford specs including WSS-M2C205-A and various other WSS specifications

Japanese & Other Asian Manufacturers:

• Red Line lists specific approvals for Honda, Mazda, Mitsubishi, and other Asian manufacturers
• AMSOIL specifically lists Honda HTO-06 certification
• It's worth noting that meeting API SP and ILSAC GF-6A standards (which both oils do) typically satisfies the basic requirements for most Japanese and Korean manufacturers

An important note about specifications: While Red Line lists more individual OEM specifications, many of these are older or legacy specifications that are automatically covered when an oil meets newer, more stringent standards like API SP and ILSAC GF-6A. AMSOIL tends to list only the most current specifications, which often encompass many of the older specifications that Red Line has listed individually.

For example, when an oil meets current API SP and ILSAC GF-6A standards (as both these oils do), it typically exceeds the requirements of many older manufacturer-specific standards. This is why some manufacturers don't require separate approvals for oils that already meet these latest industry standards.

From the industry approvals outlined above, both oils meet current industry standards for modern engines and share several important OEM approvals.

AMSOIL's approach of meeting newer specifications that supersede older ones reflects their engineering-driven background (from my perspective as a former Ford engineer, this approach makes sense as newer specs typically incorporate and improve upon older requirements). Red Line's detailed listing of individual specifications, including older ones, aligns with their racing and high-performance heritage where exact specification matching is often prioritized.

This comparison suggests that while both oils are high-quality products capable of meeting modern engine requirements, they're marketed somewhat differently to their target audiences. Neither approach is necessarily better - they just serve different customer needs and preferences.

Now let's take a look at how the specs for each 5W-30 oil compare:

*hover over each specification for more information

*Red Line High Performance has indicated via a single SDS that the Flash point is > 302 °F / > 150 °C, but because that's not specific to this weight of oil, we're not including it here.

Based on the technical comparison table we've put together, Red Line shows higher kinematic viscosity values at both 40 and 100 degrees C, suggesting it's a somewhat thicker oil despite it being 5W-30 grade. Red Line High Performance also has a slightly higher viscosity index (166 vs. 162) also suggesting slightly better viscosity stability across temperature changes.

AMSOIL Signature Series knocks it out of the park when it comes to cold-temperature performance, with a significantly lower CCS viscosity (3968 cP vs 6000 cP at -30°C) and a lower pour point (-50°C vs -45°C).

Both oils show excellent NOACK volatility ratings (AMSOIL 6.7% vs Red Line 6.0%) indicating optimal high-temperature stability and low oil consumption.

Real-World Implications:

1. Cold Weather Performance: AMSOIL has a major competitive edge in cold weather applications with better cold-cranking and pour point characteristics
2. High-Temperature Protection: Red Line's higher HTHS viscosity suggests excellent protection under extreme conditions, which aligns with their racing heritage
3. Daily Driving: Both oils offer excellent protection, with Red Line running slightly thicker and AMSOIL offering longer drain intervals
4. Oil Consumption: Both should have minimal oil consumption based on their low NOACK volatility values

• Red Line appears to prioritize maximum protection through higher viscosity and film strength
• AMSOIL balances protection with efficiency, offering excellent protection while maintaining better cold-weather performance and extended drain intervals

Neither approach is necessarily "better" - they just serve different priorities. Red Line's High Performance Oil characteristics might appeal more to high-performance applications, while AMSOIL's Signature Series' balance of properties and longer service life might better serve daily drivers who want premium protection with maximum convenience. Also important to note here that both brands offer higher performance oil lines for racing and other applications.

Pricing - AMSOIL Signature Series vs. Red Line High Performance

Out of the gate, Red Line High Performance is a bit more expensive than AMSOIL Signature Series at retail pricing. But, for Preferred AMSOIL Customers, you'll save a lot of money running AMSOIL vs. Red Line. So long as you drive less than 25,000 miles per year, you'll only need one oil change with AMSOIL and the oil will cost you much less than half of what it would cost running Red Line, even if you extend your drain interval to say 7,500 miles on Red Line.

Red Line vs AMSOIL Testing & Reviews

Cold Crank Testing

AMSOIL Signature Series 5W-30 provides better cold cranking viscosity than Royal Purple, Red Line, and Lucas Oil, helping improve wear protection for engine components at startup.

ASTM D5293 is a cold-crank simulation test that helps us see how easily oil will flow during engine startup, especially after the vehicle has been sitting for a while or is in a cold climate. This is one of the most important times for your engine oil; using a low quality oil could heavily contribute to unnecessary wear.

In this independent performance test, Red Line High Performance 5W-30 scored almost last for CCS Viscosity at right around 6000 mPas while AMSOIL Signature Series 5W-30 came out on top with a viscosity of 3800 mPas.

Based on independent third-party testing in the industry-standard ASTM D5293 Cold Crank Simulator test as required by SAE J300.‍

For the most protection during startup, especially in colder climates, AMSOIL Signature Series is the obvious choice.

Customer Reviews

I have used Pennzoil and Red Line in my Ram and have found a more stable oil pressure reading from cold to hot with Amsoil.
-DG in Pennsylvania

I switched my oil products from Red Line to Amsoil a few years ago! I have no regrets, after a 5K oil change Amsoil looks and feels like it could go another 5K. I cant honestly say that about Red Line.
- Gary

Dealer Review

I had just signed up to be an AMSOIL Dealer but was selling Red Line, Royal Purple, Mobil 1, etc. at my shop as well. I needed to get rid of a few brands and concentrate on just a few.  One day on a whim, I decided I was going to give an impromptu call to every single brand and demand to talk to the “BOSS”.  Because of the excellent marketing materials that AMSOIL provided, I knew who A.J. was to the company of AMSOIL.  I called Mobil, Red Line, Royal Purple, Lucas, etc. and I spent hours trying to reach the “top;” I talked to a regional sales manager at best.  AMSOIL was my last call to make.  I called the 800 number and immediately demanded that I talk to “Al Amatuzio!”  Surprisingly, I was connected to the personal secretary of Al.  She screened my called and asked why I was calling.  I told her that I had no reason…I just wanted to see if I could talk to the man “at the top” about why I should be a Dealer.  She told me she would check and see if he was available.  I waited approximately 2 minutes on hold until she came back on the line and said, “One moment, please. I’ll transfer you to his office now.”  

I was dumbfounded!  Seconds later, Al answered the phone.  I was young (in my 20s) and inexperienced with talking with anyone of the “corporate” stature.  Al wasted NO time getting me to feel comfortable and establishing a rapport.  He made me feel needed, necessary and important.  

Needless to say, after I hung up the phone, I slapped a clearance price on every bottle of oil on my shelves that did not bear the AMSOIL name.  I dedicated myself to become the first T1 certified Dealer for my area. A lot of things have changed for me over the past 15 years, but not my commitment to AMSOIL.  I have used virtually every product manufactured/sold by under the AMSOIL brand personally.
Brian & Jennifer O.

AMSOIL or Red Line?

In my opinion, both AMSOIL and Red Line represent the premium end of the synthetic oil market, each with distinct strengths that align with their company philosophies. After comparing specifications, approvals, and pricing, here's what stands out to me:

Red Line High Performance advantages:

• Higher viscosity measurements and HTHS values suggest excellent protection under extreme conditions
• Strong heritage in racing applications with proven performance
• Extensive use of premium polyol ester base stocks
• Good viscosity stability across temperature ranges

AMSOIL Signature Series advantages:

• Superior cold-weather performance with better cold-cranking and pour point characteristics
• Excellent protection under extreme conditions, just a few percent difference compared to Red Line
• Documented 25,000-mile drain interval capability
• More economical long-term cost, especially with Preferred Customer pricing
• Higher published TBN suggesting strong long-term acid neutralization

For performance enthusiasts who prioritize maximum protection, don't mind more frequent oil changes, and don't mind paying significantly more for engine oil, Red Line High Performance oil offers excellent protection. Their higher viscosity characteristics and racing heritage make them a solid choice for performance applications.

For drivers seeking premium protection with maximum convenience and value, AMSOIL Signature Series offers an impressive balance of protection and efficiency, backed by a guaranteed 25,000-mile drain interval. The significant cost savings from extended drain intervals, combined with superior cold-weather performance, make it particularly appealing for daily drivers in varied climates. And AMSOIL's 13 distribution centers across North America make online ordering and shipping very easy and fast.

Neither choice is wrong - it really comes down to your specific needs and preferences. But, if you want the protection you demand and the performance you deserve at a reasonable price point, choose AMSOIL.

Sources

• Red Line High Performance 5W-30 Product Data Sheet
• AMSOIL Signature Series 5W-30 Product Data Sheet