Toyota vehicles with automatic transmissions use the WS fluid specification. This fluid absorbs moisture and should never be reused. Always use fluid from an unopened container. According to Toyota, under normal usage the fluid has a 160,000 km (100,000 miles) maintenance interval for inspection only; ATF-WS does not require any flushing or changing during the life of the vehicle; however, an inspection of the maintenance schedule of many Toyota vehicles reveals that there is a 100,000 km (60,000 miles) replacement interval if the vehicle is used on short trips, city driving, hauling heavy loads, trailer towing, or using a car-top hauler. Check your own maintenance schedule for your vehicle’s requirements. Also liaise with you automobile mechanical engineer/Mechanic for  the right use of this product.