For heavy-duty manual transmissions, Chevron Delo Synthetic Transmission Fluid SAE 50 and Texaco Syn-Star TL SAE 50 provide reduced component wear and potential fuel economy improvements, says Chevron. The all-season synthetic lubricants feature high viscosity and low pour point for severe climates and operating conditions. The transmission fluids come with the Chevron Delo and Texaco Bumper-to-Bumper Lubricants warranty.