AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil - 1QT / 1GAL

AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil is a premium full synthetic engine oil engineered for drivers who want maximum protection, strong engine cleanliness, and extended drain performance. AMSOIL markets it as its top-tier gasoline motor oil and says it delivers 75% more engine protection against horsepower loss and wear, 50% more cleaning power than AMSOIL OE, 72% better turbocharger protection than required by the GM dexos1 Gen 2 test, and guaranteed protection for up to 25,000 miles or 1 year in normal service.

Designed for modern gasoline engines operating under heat, turbocharged conditions, daily driving, and long service intervals, Signature Series 5W-30 delivers strong film strength, excellent detergency, and stable viscosity performance where lower-quality oils can break down or leave harmful deposits behind. AMSOIL also says it provides 100% protection against LSPI in the GM dexos1 Gen 2 LSPI test and strong resistance to turbo coking and sludge formation.

Built as a premium extended-drain full synthetic motor oil, this oil is ideal for performance street cars, turbocharged daily drivers, and high-quality maintenance on gasoline engines that require 5W-30. It is also compatible with other conventional and synthetic motor oils, although AMSOIL says mixing oils shortens the oil’s life expectancy and reduces performance benefits.

Performance tier

Top tier – street / performance / extended drain

Developed for drivers who want maximum engine protection, strong cleanliness, turbo protection, and long drain interval capability in engines that require 5W-30 motor oil.

Variants

5w-30 – quart bottle
Best for standard oil changes and top-off use

5w-30 – gallon jug
Best for standard oil changes

Features

100% synthetic motor oil
75% more engine protection against horsepower loss and wear
50% more cleaning power vs amsoil oe motor oil
Protects turbochargers 72% better than required by the GM dexos1 Gen 2 specification
100% protection against LSPI in the required GM test
90% better protection against sludge
Excellent viscosity stability for long service life
Trusted by professional engine builders 

Fitment

Gasoline engines requiring 5w-30 motor oil
Turbocharged and naturally aspirated street applications
Performance street cars and daily drivers
Domestic and import applications

Use in applications requiring API SP Resource Conserving, SN PLUS, SN, GM dexos1 Gen 3, ACEA A5/B5, ACEA A1/B1, Honda HTO-06, Ford WSS-M2C946-B1 / WSS-M2C946-A / WSS-M2C929-A / WSS-M2C961-A1, Chrysler MS-6395, and ILSAC GF-6A / GF-5 / GF-4. Always verify the required viscosity and specification with the vehicle owner’s manual before use.

Specifications

Type: 100% synthetic motor oil
Viscosity: 5w-30
Product code: ASLQT-EA
Available sizes: quart bottle / gallon jug
Kinematic viscosity @ 100°C: 10.3 cSt
Kinematic viscosity @ 40°C: 59.7 cSt
Viscosity index: 162
CCS viscosity: 3968 cP @ -30°C
Flash point: 220°C / 428°F
Fire point: 244°C / 471°F
Pour point: -50°C / -58°F
NOACK volatility: 6.7%
HTHS viscosity @ 150°C: 3.11 cP
Total base number: 12.5
Brand: AMSOIL 

For extended-drain use, AMSOIL states normal service is up to 25,000 miles, 700 hours, or 1 year, while severe service is up to 15,000 miles, 700 hours, or 1 year. AMSOIL also says modified engines, racing vehicles, and vehicles using alternative fuels like E85, CNG, or propane are excluded from its extended drain interval recommendations.

Note

This oil is built for premium street use and extended service performance. AMSOIL says it is compatible with other oils, but mixing reduces performance benefits and it does not support extended drain intervals where oils have been mixed. AMSOIL also recommends using AMSOIL Oil Filters for best performance.

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Recommended pairings

AMSOIL Severe Gear
AMSOIL coolant