Allison Transmission Builds on Demonstrated Performance and Improved Shift Quality with Newly Formulated Automatic Transmission Fluid

TES 668™ utilizes the latest developments in synthetic fluid formulation and additive technologies to meet the needs of current and future applications.

INDIANAPOLIS, September 28, 2020 Allison Transmission, the largest global manufacturer of medium- and heavy-duty fully automatic transmissions, announced today a new formulation of its high-performing transmission fluid. TES 668™ is a modern formulation with many advantages compared to mineral-based, non-synthetic fluids. This next generation transmission fluid is specified for all Allison 1000 SeriesTM, 2000 SeriesTM, 3000 SeriesTM and 4000 SeriesTM automatic transmissions.

TES 668 builds on the demonstrated performance of TES 295® fluid in a number of key areas, such as oxidative stability, anti-wear performance and friction modifier durability. These factors improve the quality of the shifts and reduce the noise, vibration and harshness experienced as the fluid ages. Better friction performance provides more consistent clutch application—even across temperature variations and load sizes.

The robust formulation of TES 668 meets the most demanding specs related to fluid stability, lubrication and cold operation. This allows Allison to back long drain intervals, even when operating under heavy loads. TES 668 is specified for Allison products to ensure ideal operation. There are a range of problems that come from using an unapproved fluid in an Allison product, such as seal and friction issues, which will impact overall product durability. Using genuine automatic transmission fluid from an Allison Approved or Authorized partner is key to optimum performance and the long-lasting durability of Allison’s products.

“We are pleased to offer the enhanced fluid. This is yet another example of how Allison strives to continually progress our products and services with our mission of improving the way the world works,” said Brian Geiselhart, Allison Transmission Managing Director, Global Channel, Aftermarket & Warranty.

Allison Transmission is in the process of providing additional approvals for multiple oil marketers and our website will continually be updated to reflect that. Click here for the full list of TES 668 approved vendors.

28 Sep, 2020


Allison Transmission (NYSE: ALSN) is a leading designer and manufacturer of vehicle propulsion solutions for commercial and defense vehicles, the largest global manufacturer of medium- and heavy-duty fully automatic transmissions, and a leader in electrified propulsion systems that Improve the Way the World Works. Allison products are used in a wide variety of applications, including on-highway trucks (distribution, refuse, construction, fire and emergency), buses (school, transit and coach), motorhomes, off-highway vehicles and equipment (energy, mining and construction applications) and defense vehicles (tactical wheeled and tracked). Founded in 1915, the company is headquartered in Indianapolis, Indiana, USA. With a presence in more than 150 countries, Allison has regional headquarters in the Netherlands, China and Brazil, manufacturing facilities in the USA, Hungary and India, as well as global engineering resources, including electrification engineering centers in Indianapolis, Indiana, Auburn Hills, Michigan and London in the United Kingdom. Allison also has approximately 1,600 independent distributor and dealer locations worldwide. For more information, visit