Freedom Series 15W-50 100% Synthetic Racing Oil is designed for those who demand superior protection for their high-performance engines. Freedom Series emerged when AMSOIL and Fleece Performance Engineering partnered to develop an advanced formulation for diesel racing vehicles equipped with Fleece Performance products. It is specifically engineered to deliver maximum protection and performance for high-horsepower and turbocharged competition diesel engines.
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Product data sheets
View, download, or save a copy of the Product Data Sheet or Safety Data Sheet for Freedom Series 15W-50 100% Synthetic Racing Oil.
Freedom Series 15W-50 100% Synthetic Racing Oil is a heavyweight 100 percent synthetic engine oil engineered for high-horsepower, turbocharged competition diesel engines. The grade was developed jointly by AMSOIL and Fleece Performance Engineering for performance-modified diesels that specify API CK-4 (and prior) and run Fleece Performance products, and it is purpose-built for the cylinder pressures, fuel dilution, and turbocharger heat seen in sled pulls, drag races, and dyno competition.
Wear protection in performance-modified diesels
Racing and high-performance diesel engines are modified to deliver maximum horsepower and torque, and the resulting shearing forces can cause an oil to thin and leave bearings, pistons, and other components vulnerable to scuffing and wear. Freedom Series 15W-50 is heavily fortified with zinc and phosphorus anti-wear additives to withstand high cylinder pressures and provide extra protection against scuffing and wear under severe-duty competition service.
Viscosity control under fuel dilution
High-horsepower diesels push more fuel through the cylinders, and a portion of that fuel works past the rings into the crankcase. Fuel dilution thins the oil and compromises lubrication at bearings and ring belts. Freedom Series 15W-50 holds a heavy 21.0 cSt kinematic viscosity at 100 C (ASTM D445) and a 5.6 cP high-temperature high-shear viscosity (ASTM D5481), so the protective film stays intact when the oil sees fuel dilution and severe shear together.
Turbocharger heat and deposit control
Turbo bearings sit downstream of the hottest section of the engine, and oxidation in that environment drives turbo deposits, reduced spool response, and the kind of catastrophic failures that end a pull or a pass. The 15W-50 synthetic formulation contains maximum levels of oxidation-inhibitor additives to resist deposit formation and preserve turbocharger performance and life under sustained boost. Compound turbo arrangements and aggressive fueling profiles common to performance-modified diesel builds run the oil hotter and longer than a stock setup, and that environment is exactly where the synthetic chemistry pays off.
NOACK volatility and alkaline reserve
Lower volatility keeps the lightest oil fractions in the sump at race temperatures, which slows viscosity drift and helps keep make-up oil consumption in check. The 15W-50 grade records a 4.7 percent NOACK volatility (ASTM D5800) and a 10.5 Total Base Number (ASTM D2896), giving the formula an alkaline reserve to neutralize the acidic combustion byproducts produced by aggressive fueling, hot exhaust gas temperatures, and high boost.
Cold-cranking flow and pour point
Even competition engines see a cold start in the staging lanes or on a sled-pull morning. Freedom Series 15W-50 reaches a CCS viscosity of 5,856 cP at -20 C (ASTM D5293) and a pour point of -39 C (ASTM D97), giving the formula low-temperature flow that supports a clean start and steady oil pickup before warm-up and full launch.
Recommended applications and service intervals
Freedom Series 15W-50 (FD1550) is a competition racing oil for performance-modified diesels equipped with Fleece Performance Engineering products. The intended applications are tight, and the grade is not designed as a daily-driver heavy-duty diesel oil.
Performance-modified diesel engines specifying API CK-4 (and prior).
Diesel racing vehicles equipped with Fleece Performance Engineering products.
Sled pull, drag race, and dyno competition use.
Not intended for daily-driver gasoline service or for non-Fleece-equipped diesels operating outside competition.
When competing, the vehicle owner is responsible for determining the appropriate service interval, and race-engine oil intervals are typically governed by used-oil analysis. Freedom Series 15W-50 is compatible with other conventional and synthetic engine oils, but mixing AMSOIL racing oil with other oils reduces its performance benefits. Aftermarket oil additives are not recommended for use with Freedom Series 15W-50.
Typical technical properties
Property
Value
Kinematic Viscosity at 100 C, cSt (ASTM D445)
21.0
Kinematic Viscosity at 40 C, cSt (ASTM D445)
157.0
CCS Viscosity, cP at -20 C (ASTM D5293)
5,856
Pour Point, C (ASTM D97)
-39
NOACK Volatility, percent weight loss (ASTM D5800)
Freedom Series 15W-50 100% Synthetic Racing Oil is available in quart bottle (FD1550QT-EA) and case of 12 quarts (FD1550QT-CA). Using AMSOIL synthetic lubricants and practicing extended drain intervals does not void a new vehicle or equipment manufacturer warranty, and all AMSOIL lubricants and filters are covered by the AMSOIL Limited Warranty. Confirm application match for the Fleece-equipped diesel in the AMSOIL Vehicle Lookup Guide, compare diesel viscosity and OEM spec options in the AMSOIL Diesel Oil Guide, then order Freedom Series 15W-50 100% Synthetic Racing Oil.
Frequently asked questions
What engines is Freedom Series 15W-50 designed for?
Freedom Series 15W-50 is engineered for performance-modified diesel engines that specify API CK-4 (and prior) and are equipped with Fleece Performance Engineering products. Typical applications include high-horsepower, turbocharged competition diesels run in sled pulls, drag races, and dyno events.
Can Freedom Series 15W-50 be used in a daily-driver diesel pickup?
The formula is intended for competition service in Fleece-equipped racing diesels, not as a general heavy-duty diesel oil for daily driving. Owners of daily-driver turbodiesel pickups should compare the on-highway diesel grades in the AMSOIL Diesel Oil Guide and confirm the correct viscosity and OEM spec in the AMSOIL Vehicle Lookup Guide.
Does Freedom Series 15W-50 carry API CK-4?
The 15W-50 is designed for diesel engines specifying API CK-4 (and prior). It is a competition racing oil, so service intervals are determined by the vehicle owner rather than by a heavy-duty on-highway category drain recommendation.
What does the high zinc and phosphorus additive package do?
Zinc and phosphorus anti-wear chemistry forms a sacrificial film on highly loaded metal surfaces such as bearings, piston skirts, and ring belts that absorbs scuffing and shear during high cylinder pressure events. Freedom Series 15W-50 is heavily fortified with zinc and phosphorus to deliver that protection in the severe conditions of competition diesel service.
How long can the oil stay in service in a race engine?
When competing, the vehicle owner is responsible for determining the appropriate service interval. Race-oil intervals are typically governed by used-oil analysis, fuel dilution levels, soot loading, and the operating profile of the specific engine and event series.
Can Freedom Series 15W-50 be mixed with other oils?
The formula is compatible with other conventional and synthetic engine oils, but mixing AMSOIL racing oil with other oils reduces its performance benefits. Aftermarket oil additives are not recommended for use with Freedom Series 15W-50.
Will running Freedom Series 15W-50 void a new vehicle warranty?
No. Using AMSOIL synthetic lubricants and practicing extended drain intervals does not void a new vehicle or equipment manufacturer warranty, and all AMSOIL lubricants and filters are covered by the AMSOIL Limited Warranty.
