AMSOIL Synthetic SAE 50 Long-Life Transmission Oil

The Benchmark for Over the Road Trucking!

SAE 50 Long-Life Synthetic Transmission Oil (FTF)

Specifically Engineered for 500,000-Mile Service Life in Over-The-Road Trucks.

Here at the Synthetic Warehouse this product enjoys regular feedback about the smooth shifting it delivers. A premium product that lasts long for a reasonable price. Other fluids do go this long but as they age they lose their performance. AMSOIL SAE 50 performs just like it did out of the container right to the end of the 500,000 service interval.

Created out of demand by our expanding OTR customer base concerned with controlling costs.

AMSOIL SAE 50 Long-Life Synthetic Transmission Oil is specially formulated to meet the demanding requirements of manual transmissions found in high-torque, heavy-duty line-haul trucks and other commercial applications. Its synthetic base oils and premium additives help reduce wear (see photos), improve shifting and extend transmission life throughout drain intervals of up to 500,000 miles/five years. Compared to conventional fluids, Long-Life Synthetic Transmission Oil can help operators reduce maintenance costs and increase productivity.

Check Price or Buy

Call 800-579-0580 for competitive current price.
Or use the
online preferred customer portal if you choose to order online and save 20 to 25% off of the retail price.

Package sizes include:
5-gallon jug;
Drums in 16, 55
275 gallon totes.

Printable Product Data Sheet for AMSOIL SAE 50 Transmission Oil

Resists Wear

AMSOIL Long-Life Synthetic Transmission Oil’s synthetic base oils withstand the pressures of high-load, high-torque applications. As a result, it resists viscosity loss due to mechanical shear to provide a durable lubricating fluid film for increased wear resistance and longer transmission life.

To prove its effectiveness, AMSOIL installed SAE 50 Long-Life Synthetic Transmission Oil in line-haul trucks and placed them into real-world service. After more than 500,000 miles, a transmission was disassembled and inspected by a calibrated ASTM rater. Results reveal Long-Life Synthetic Transmission Oil provided outstanding wear protection in all critical components (see images).

Year-Round Performance

AMSOIL Long-Life Synthetic Transmission Oil’s high viscosity index translates into better high- and low-temperature performance compared to conventional fluids. In cold weather, it provides easier shifts and reduced fluid drag for increased fuel economy. Its exceptional thermal stability inhibits chemical breakdown and sludge formation at high operating temperatures to help transmissions run cleaner.

Inhibits Foam

Churning gears introduce air into the fluid, causing foam. When bubbles between gear surfaces collapse, metal-to-metal contact and increased wear result. Long-Life Synthetic Transmission Oil contains foam inhibitors to ensure formation of a strong lubricating film and excellent wear protection.

Seal Friendly

Long-Life Synthetic Transmission Oil is compatible with seals to help prevent leaks and extend seal life.


AMSOIL SAE 50 Long-Life Synthetic Transmission Oil is excellent for use in manual transmissions requiring an SAE 50 lubricant found in heavy-duty equipment. It is recommended for applications specifying any of the following:

  • Eaton* PS-164 Rev. 7
  • API GL-1 and MT-1
  • Navistar*/International* TMS 6816
  • Mack* TO-A Plus
  • ZF* Freedomline
  • Meritor* 0-81
  • Rockwell*/Eaton/Fuller* CD-50 (PS-081)

Service Life

Follow the OEM drain interval for synthetic oil up to 500,000 miles or five years, whichever comes first.


AMSOIL products are backed by a Limited Liability Warranty. For complete information visit


This product is not expected to cause health concerns when used for the intended applications and according to the recommendations in the Safety Data Sheet (SDS). An SDS is available online at or upon request at (715) 392-7101. Keep Out of Reach of Children. Recycle used oil and bottle.

Answering your AMSOIL Questions regarding the SAE 50 Long Life Transmission Gear Oil.

1. Question:
What is AMSOIL SAE 50 Long-Life Synthetic Transmission Oil?

AMSOIL SAE 50 Long-Life Synthetic Transmission Oil (FTF) is a heavy-duty manual transmission oil designed to meet original equipment manufacturers’ extended drain requirements up to 500,000 miles or five years.

2. Question:
What are the primary markets and customers for AMSOIL Long-Life Transmission Oil?

Markets include over-the-road trucking, short trip delivery, heavy-duty and transportation. The primary customers for AMSOIL Long-Life Transmission Oil are companies and owner operators requiring a premium performance SAE 50 transmission oil designed to perform in severe service environments or those desiring 500,000 mile drain intervals.

3. Question:
Why did AMSOIL develop 500,000 mile drain interval transmission oil?

In the trucking industry, 500,000 mile transmission and differential drain intervals are common. AMSOIL currently offers 75W-90 Long-Life Synthetic Gear Lube (FGR) and 75W-140 Long Life Synthetic Gear Lube (FGO) for differential drain intervals of up to 500,000 miles for over-the-road truck (line-haul) applications.
The addition of SAE 50 Long-Life Transmission Oil provides our accounts with a complete line of long drain driveline products for these applications.

4. Question:
What are the main benefits of using AMSOIL SAE 50 Long-Life Synthetic Transmission Oil?

AMSOIL Long-Life Transmission Oil can help lower costs due to longer drain intervals and provides for fuel efficiency gains. It offers outstanding wear protection, excellent cold temperature performance for enhanced shifting and superior seal compatibility to help reduce leaks.

5. Question
What transmissions should use AMSOIL Long-Life Transmission Oil?

AMSOIL Long-Life Transmission Oil can be used in transmissions that require SAE 50 oil with any of the following long-drain specifications:
• API GL-1 and MT-1
• Eaton PS-164 Rev. 7
• Mack TO-A Plus
• Navistar/International TMS 6816
• ZF Freedomline
• ArvinMeritor 0-81
• Volvo I-Shift

6. Question:
What is the difference between line-haul, over-the-road and other truck applications?

Generally, over-the-road (OTR) and line-haul are used interchangeably in the trucking industry. Line-haul/over-the-road can be defined as traveling over 60,000 miles per year on paved roads with trips lasting over 30 miles. This definition differentiates short-trip and off-road applications from the higher mileage trucking applications.

7. Question:
What is the recommended drain interval for AMSOIL Long-Life Transmission Oil?

AMSOIL recommends following the manufacturers’ drain interval for heavy-duty transmissions up to 500,000 miles or five years. Manufacturers normally specify drain intervals of less than 500,000 miles for applications other than line haul/over-the-road.

8. Question:
What testing has been done to confirm that AMSOIL Long-Life Transmission Oil provides protection for 500,000 miles?

AMSOIL conducted a carefully controlled 500,000 mile field trial as part of the product validation. Samples were taken throughout the field trial to monitor transmission wear and oil condition. At the end of the field trial, a tear down and examination was completed. A certified third party technician rated key transmission parts which showed AMSOIL SAE 50 Long- Life Synthetic Transmission Oil provided excellent wear protection and gasket performance. Parts were good for continued use, and no seal leaks were noted on any of the trucks during the study period.

9. Question:
What package sizes will Long-Life Transmission Oil be available in?
AMSOIL Long-Life Transmission Oil is available in the following packaging sizes:
• FTF05 – 5 gallon pails
• FTF16 – 16 gallon drums
• FTF55 – 55 gallon drums
• FTF27 – 275 gallon totes

For more help, pricing or to set your fleet up with a direct order at cost account call us anytime at 605-361-4075. We will forward you the list of AMSOIL depots across the country as well as low cost shipping options.