Vehicles have recently seen tremendous gains in both horsepower and towing limits.  In fact, horsepower has increased by as much as 93 percent in turbo diesel trucks and vehicle towing limits have increased from

7,500 to 18,000 lbs. in recent years, causing differentials to run hotter than ever.  At the same time, vehicle

manufacturers have been under pressure to meet government-mandated fuel efficiency requirements.

   The Society of Automotive Engineers (SAE) sets viscosity parameters for gear lubes in its SAE J-306 document.  Until recently, the viscosity range for SAE 90 gear lubes was very broad, ranging from 13.5 cSt to <24 cSt.  Because correct gear lube viscosity is critical to proper lubrication, gear manufacturers have been concerned the gear lubes on the low end of the SAE 90 scale may not provide adequate protection.  At 16.4 cSt, AMSOIL SEVERE GEAR ® 75W-90 Synthetic Gear Lube (SVG) is formulated well within the SAE 90 viscosity range and has always ensured superior viscosity protection in systems specifying an SAE 90 gear lubricant.  In order to ensure adequate gear protection, some manufacturers, including Ford, recommend an SAE 140 gear lubricant.  However, the use of an SAE 140 gear lubricant increases viscosity drag and reduces the efficiency of the gear system, resulting in increased energy consumption and decreased fuel

economy.

   SAE J-306 was modified in 2006 to break up the broad viscosity range of SAE 90.  With a viscosity range

of between 18.5 cSt and <24 cSt, the new SAE 110 classification is midway between SAE 90 and SAE 140.  This new classification assures gear manufacturers of sufficient viscosity protection, as well as improved efficiency and fuel economy over SAE 140 gear lubricants.  A similar viscosity range break-up occurred with the SAE 140 classification, with the new SAE 190 classification splitting the range between SAE 140 and SAE 250.  SAE 190 and 250 gear lubricants are thick viscosity oils for special applications.

   Although no manufacturers currently specifically recommend SAE 110 viscosity gear lubes, they fulfill the requirements of the previous SAE 90 classification and may be used wherever SAE 90 is recommended.  New 75W-110 SEVERE GEAR Synthetic Gear Lube (SVT) provides superior protection for elevated operating temperatures without sacrificing fuel efficiency.  It is formulated for use with limited slip clutches and is ideal

for turbo diesel pick-up trucks, vehicles used for towing and hauling and other vehicles subject to severe service operating conditions, including heavy equipment, construction vehicles, emergency vehicles, street rods and 4x4 vehicles.  It is recommended in applications specifying API GL-5 or MT-1 and MIL-PRF-2105E.

   AMSOIL 75W-110 SEVERE GEAR Synthetic Gear Lube joins 75W-90 (SVG) and 75W-140 (SVO) SEVERE

GEAR Synthetic Gear Lubes as premium grade lubricants specifically engineered for maximum performance

in severe duty applications.  SEVERE GEAR Synthetic Gear Lubes feature an exclusive blend of high viscosity,

shear stable synthetic base stocks and an extra treatment of high-performance additives, maintaining

viscosity for long-lasting protection against metal-to-metal contact in both hot and cold temperature

extremes.  The proprietary AMSOIL additives form an iron-sulfide barrier coating on gear surfaces, providing the ultimate line of defense against wear, pitting and scoring.  SEVERE GEAR Synthetic Gear Lubes help prevent “thermal runaway,” a phenomenon caused by a lubricant’s inability to control friction and increased heat under high stress conditions.  By controlling thermal runaway, SEVERE GEAR Synthetic Gear Lubes inhibit rapid lubricant degradation and component damage.  AMSOIL SEVERE GEAR Synthetic Gear Lubes provide extended drain intervals of 100,000 miles in normal service or 50,000 miles in severe service, or longer if specified by the owners manual.

   AMSOIL SEVERE GEAR Synthetic Gear Lubes are recommended for use in differentials, manual transmissions

and other gear applications requiring any of the following specifications: API GL-5, MT-1, MIL-PRF-

2105E, Dana SHAES 234 (formerly Eaton PS-037), Mack GO-J or the differential (hypoid) gear lube specifications from GM, DaimlerChrysler, Ford and all other domestic and foreign vehicle manufacturers.  SEVERE GEAR Synthetic Gear Lubes may also be used in axles where an API GL-4 lubricant is recommended.

   Specific recommendations for SEVERE GEAR Synthetic Gear Lubes are as follows:

   SEVERE GEAR 75W-90 (SVG) replaces competitive 75W-90 and 80W-90 gear lubricants.  It delivers the

best fuel efficiency and cold temperature performance in the SEVERE GEAR line.

   SEVERE GEAR 75W-110 (SVT) replaces competitive 75W-110, 75W-90 and 80W-90 gear lubricants.  It delivers better viscosity protection than SEVERE GEAR 75W-90 and better fuel efficiency than SEVERE GEAR

75W-140.

   SEVERE GEAR 75W-140 (SVO) replaces competitive 75W-140, 80W-140 and 85W-140 gear lubricants.  It