Choosing the right motor oil for your vehicle doesn't have to be complicated. With a basic understanding of viscosity grades, manufacturer specifications, and AMSOIL's product tiers, you can confidently select the perfect oil for your engine.
Step 1: Check Your Owner's Manual
Your vehicle's owner's manual is always the best starting point. It specifies the recommended viscosity grade (such as 5W-30 or 0W-20) and the industry specifications your oil must meet (such as API SQ, ILSAC GF-7 or GM dexos1 Gen 3). Using an oil that meets or exceeds these specifications ensures your engine receives the protection it was designed for, and keeps your warranty intact. If you buy oil more than once a year, read whether the Preferred Customer program is worth it.
Step 2: Understand Viscosity Grades
The numbers on an oil bottle, like 5W-30, indicate its viscosity characteristics. The first number (5W) represents cold-weather flow: lower numbers mean the oil flows more easily in cold temperatures, providing faster startup protection. The second number (30) represents the oil's viscosity at operating temperature: higher numbers mean thicker oil at operating temperature, which provides a stronger protective film.
Modern engines are designed with tighter tolerances and typically require thinner oils (0W-20, 5W-20, 5W-30) to maximize fuel efficiency while maintaining adequate protection. Always use the viscosity recommended by your vehicle manufacturer.
Step 3: Choose Your AMSOIL Performance Tier
AMSOIL offers three tiers of synthetic motor oil, each designed for different needs and budgets:
Signature Series is AMSOIL's flagship product line, offering up to 25,000-mile or one-year drain intervals (15,000 miles in severe service). It provides the highest level of wear protection, deposit resistance, and thermal stability. This is the best choice for enthusiasts, high-mileage drivers, and anyone who wants maximum protection and the longest possible drain intervals.
Extended-Life (XL) offers up to 20,000-mile or one-year drain intervals and 12,000 miles in severe service at a lower price point than Signature Series. It provides outstanding protection and extended service life, an excellent balance of performance and value for most drivers.
OE Synthetic is designed as a direct replacement for conventional and synthetic-blend oils at OEM-recommended drain intervals. It meets or exceeds the specifications required by your vehicle manufacturer, making it ideal for new vehicles under warranty or fleet operations that follow manufacturer maintenance schedules.
Step 4: Use the AMSOIL Product Lookup Tool
The easiest way to find exactly what your vehicle needs is AMSOIL's online product lookup tool. Simply enter your year, make, and model, and the tool will display every AMSOIL product recommended for your vehicle, including motor oil, transmission fluid, gear lube, filters, and more.
Step 5: Consider Your Driving Conditions
Your driving habits and conditions can influence which tier is best for you. If you frequently tow heavy loads, drive in extreme heat, make many short trips, or drive in dusty conditions, you may benefit from the additional protection and drain interval confidence of Signature Series. For typical daily commuting, Extended-Life or OE Synthetic may be the perfect fit.
Still Not Sure? Ask Eric.
If you're still unsure which product is right for your vehicle, I'm happy to help. Contact me with your year, make, model, and how you use your vehicle, and I'll provide a personalized recommendation at no cost.
Frequently Asked Questions About Choosing AMSOIL
What's the difference between AMSOIL OE, Extended-Life and Signature Series?
OE Synthetic is made for the drain intervals your vehicle maker recommends or your oil life monitor shows. Extended-Life (formerly XL) is rated for up to 20,000 miles or one year in normal service and 12,000 miles in severe service. Signature Series is AMSOIL's top motor oil, rated for up to 25,000 miles or one year in normal service and 15,000 miles in severe service.
What does the 'W' mean in AMSOIL 5W-30?
The 'W' stands for 'Winter.' The number before the W (5W) indicates the oil's cold-flow performance, lower numbers flow better in cold temperatures. The second number (30) represents viscosity at normal operating temperature. So 5W-30 flows easily in cold starts while maintaining a stable protective film when your engine is hot.
Will AMSOIL void my car warranty?
No. The Magnuson-Moss Warranty Act prohibits vehicle manufacturers from requiring a specific brand of motor oil. As long as the oil meets the specifications listed in your owner's manual, your warranty remains intact. Check that the AMSOIL product lists the spec your owner's manual calls for.
Is AMSOIL API certified?
AMSOIL lists Signature Series 5W-30 for API SQ (Resource Conserving), ILSAC GF-7A and GM dexos1 Gen 3, among others. Each product's data sheet lists the exact specs it meets, so check it against your owner's manual.
What AMSOIL oil do I use for a turbocharged engine?
Turbocharged engines are hard on oil. Signature Series is a strong choice, but the first rule is to match the viscosity and spec in your owner's manual. Call me and I'll check it for your engine.
Is AMSOIL safe for older, high-mileage engines?
Yes. AMSOIL synthetic motor oil can be used in older engines. If an older engine is using or leaking oil, call me and we'll look at what it needs before picking a product.
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