AMSOIL Comparison: Signature Series vs. European vs. OE vs. XL vs. High-Mileage

As an AMSOIL Regency Platinum 12-Star Direct Jobber and former Ford Motor Company Truck/Automotive Engineer, I've spent decades working with and testing various lubricants. Today, I want to share my insights on AMSOIL's most popular oil lines to help you make the best choice for your vehicle.

AMSOIL has been a pioneer in synthetic motor oils since 1972, consistently delivering high-quality products designed to meet the demands of modern engines. With over 50 years of experience, AMSOIL offers a range of oil formulations to suit virtually any application. However, the variety of options can be overwhelming for consumers. In this article, we'll break down the key differences between AMSOIL's most popular engine oil lines:

1. Signature Series
2. European Motor Oil
3. OE (Original Equipment)
4. XL (Extended Life)
5. High-Mileage

Side-by-Side Comparison

Let's start with a quick overview of all of these oil lines:

AMSOIL Oil Lines Comparison

Feature	Signature Series	European Motor Oil	XL (Extended Life)	High-Mileage	OE (Original Equipment)
Drain Interval	Up to 25,000 miles or 1 year	Follow OEM recommendations	Up to 20,000 miles or 1 year	Up to 12,000 miles or 1 year	Follow OEM recommendations
Best For	Maximum protection and performance	European and exotic vehicles	Extended protection, longer intervals	Vehicles with 75,000+ miles	Cost savings, newer vehicles
Key Benefit	Ultimate wear protection	Meets strict European specifications	Excellent protection with longer intervals	Helps reduce oil consumption and emissions	Cost-effective protection that beats OEM oils
Relative Price

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Signature Series vs. High-Mileage vs. XL vs. OE

Signature Series provides up to 25,000 miles of protection (or one year) when combined with the AMSOIL EAO Filter, Extended-Life (XL) offers 20,000 miles of protection between changes, High-Mileage can run 12,000 in engines over 75k miles, and for OE (Original Equipment) and AMSOIL European Oils it's recommended to follow the manufacturers specifications.

Now, let's dive deeper into each product line and their comparisons.

AMSOIL Signature Series vs. European Motor Oils

While both of these lines represent AMSOIL's premium offerings, they serve different purposes:

Signature Series

• Provides the absolute best protection AMSOIL offers
• Suitable for most North American and Asian vehicles
• Exceptional high-temperature stability and wear protection
• Up to 25,000-mile drain intervals when used with an AMSOIL EaO filter

European Motor Oil

• Specifically formulated to meet strict European specifications (ACEA, VW, BMW, MB, etc.)
• Suitable for high-performance European gas and diesel engines
• Low-SAPS formulations available for vehicles with modern emissions systems with strict engine oil requirements
• Suitable for both gas and diesel engines

Comparing Oil Specifications AMSOIL Signature Series vs. European

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From the comparison above, we see that both Signature Series and European motor oil lines are high-quality oils from their specifications alone, but there are some key differences to note:

• Signature Series has a significantly higher TBN, indicating potentially better acid-neutralizing capability and better protection against oil degradation.
• Signature Series also has lower viscosity at lower temperatures and a better CCS viscosity, pointing towards better cold-start performance.
• AMSOIL European oils maintains its viscosity slightly better across temperature ranges and provides better protection in hotter conditions.

Can you run Signature Series in European vehicles?

For any European vehicles requiring ACEA C-series oil specifications, you'll likely need to use AMSOIL European Motor Oils. AMSOIL Signature Series Oils are recommended for use in European vehicles requiring ACEA A1/B1 and A5/B5 specifications that are typically light-duty diesel and gas engines.

This makes Signature Series suitable for some European vehicles, but not all, particularly:

1. Volvo: Many Volvo models specifically require ACEA A5/B5 oils.
2. Ford: Some European Ford models require ACEA A5/B5 oils.
3. Jaguar and Land Rover: Many models from these brands require ACEA A5/B5 oils.
4. Some Peugeot and Citroën models: These may require ACEA A5/B5 oils.

You can learn more about the differences between various types of AMSOIL European Motor Oils and their associated ACEA specifications here.

As someone who's worked extensively with both domestic and European vehicles, I can attest to the importance of using the correct oil specification. While Signature Series is outstanding, it may not meet all the requirements for certain European engines. Always consult your owner's manual or use AMSOIL's lookup guide to ensure compatibility.

If, after referencing your vehicle's service manual, you know you can choose between AMSOIL Signature Series and the appropriate European oil, Signature Series provides better protection for just slightly more money than the AMSOIL European counterpart.

Signature Series vs. OE (Original Equipment)

These two AMSOIL product lines cater to very different consumer needs:

Signature Series

• Premium protection for enthusiasts and those wanting the absolute best
• Extended drain intervals of 25,000 miles for reduced maintenance
• Superior engine cleanliness and wear protection

OE (Original Equipment)

• Designed as a high-performance replacement for vehicle manufacturer-branded products
• Excellent protection at a more affordable price point
• Specifically designed for newer, small-displacement engines requiring lower viscosity oils

What's the major difference between AMSOIL Signature Series and OE?

The biggest difference between these AMSOIL product lines is the cost. AMSOIL OE oils are significantly cheaper than Signature Series oils and, with a Preferred Customer membership discount, you can get a 100% synthetic AMSOIL motor oil at nearly the same price as typical conventional oils.

Comparing oil specs between Signature Series & AMSOIL OE:

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If you've read my other comparison articles, you'll know it's difficult to judge an oil based solely on it's manufacturer-listed specifications. For that reason, I tend to focus more on CCS viscosity, viscosity index, TBN (Total Base Number), and an oil's pour point when making comparisons. From the above data, we see that those four metrics (except TBN) aren't all that far off between the two oils, indicating both are extremely high quality.

TBN measures the oil's reserve alkalinity and ability to neutralize acidic byproducts of combustion that enter the engine oil over time. The higher the TBN, the longer the oil will neutralize those acidic byproducts of combustion. The difference here between SS & OE's TBN indicates Signature Series will be able to neutralize acids in the oil far longer than OE oils.

In my experience, OE is an excellent choice for most daily drivers, providing AMSOIL quality at a price point comparable to conventional oils. However, for those seeking maximum protection or extended drain intervals, Signature Series is the way to go.

AMSOIL XL (Extended Life) vs. Signature Series

Both of these lines offer extended drain intervals, but with some key differences:

Signature Series

• The ultimate in protection and performance
• Up to 25,000-mile drain intervals
• Best for severe service conditions

XL (Extended Life)

• Excellent protection with up to 20,000-mile drain intervals
• More affordable than Signature Series, you'll save a couple dollars per quart at least
• Great for those wanting longer intervals without the maximum cost

Comparing oil specifications between Signature Series and XL:

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From the oil specifications comparison, you'll notice data points that are mostly better than AMSOIL OE, but still not quite as good as the Signature Series. TBN values are much closer between the XL 5W-30 and the SS 5W-30.

I often recommend XL to customers who want to extend their oil change intervals but don't need the extreme protection (and full cost) of Signature Series. It's an excellent middle-ground option.

Signature Series vs. High-Mileage

While Signature Series can be used in high-mileage engines, AMSOIL makes High-Mileage engine oils specifically for vehicles with 75,000+ miles.

AMSOIL High-Mileage motor oils feature some key differences to help better protect high-mileage vehicles:

• More cleaning additives: boosted detergents and seal conditioners that combat oil breakdown and leaks.
• Better viscosity index: higher viscosity index allows it to maintain viscosity better at extreme temperatures to counteract compression loss and reduce engine wear.

Comparing the technical specs:

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Of all the oils we've compared so far, the AMSOIL High-Mileage 5W-30 has the highest viscosity index, indicating it's ability to maintain it's viscosity even at extreme temperatures. It also has one of the highest TBN values (right behind that of the Signature Series), which is important as higher-mileage engines will typically produce more acids in the oil that need neutralized.

In my years of experience, I've seen remarkable results with the High-Mileage formula in older vehicles. However, if your high-mileage vehicle isn't experiencing any issues, Signature Series is still an excellent choice.

Choosing the Right AMSOIL Product

When selecting an AMSOIL product, you need to consider the following factors:

1. Your specific vehicle make, model, and year.
2. Engine age and mileage.
3. Driving conditions (severe service, normal, etc.).
4. Desired oil change interval and what's specified by your OEM.
5. What are you willing to spend? 

For most of my gas-powered personal vehicles, I prefer Signature Series. The extended drain intervals and superior protection save me time and money in the long run. However, I recognize that every situation is unique, and that's why AMSOIL offers such a diverse product line.

In some of my older vehicles that I use for mostly recreational purposes, I run AMSOIL DOMINATOR racing oils.

AMSOIL's range of motor oils provides options for every type of vehicle and driver. Whether you're looking for ultimate protection with Signature Series, specialty formulations for European vehicles, cost-effective protection with OE, extended drain intervals with XL, or specialized care for high-mileage engines, AMSOIL has you covered.

Remember, the best oil is the one that meets your vehicle's specifications and your personal needs. If you have any questions about which AMSOIL product is right for you, don't hesitate to reach out. As an AMSOIL Dealer with decades of automotive engineering experience, I'm here to help you make the best choice for your vehicle.

Check out my other comparison posts!

• AMSOIL vs Mobil 1
• AMSOIL vs Royal Purple
• AMSOIL vs Liqui Moly
• Dominator vs Interceptor vs Saber