Below is a guide you can follow to crack the code of what “Lifetime” transmission fluid means and figure out what the actual service interval is for your vehicle.
Here are the key points you need to understand about transmission fluid.
- No transmission fluid lasts a “Lifetime”
- The “Lifetime of Transmission Fluid” for a car manufacture is how long they warranty the Powertrain for. (Ex. 50,000 miles)
- The “life” of transmission fluid is actually based on Transmission Operating Temperature.
- If there’s no maintenance interval listed for the transmission fluid under the normal maintenance schedule check your owners manual for the “Severe Service Schedule” that applies for vehicles used for towing or adverse driving conditions.
- Under “Severe Service” there should be a listed interval for when the transmission fluid has to be changed.
REMEMBER THIS: Severe service is typically 1/2 the milage of regular service.
Below is the formula to calculate when the fluid has to be changed under normal driving conditions:
(Take the “Severe Service mileage” listed in the owners manual) x (multiply milage by 2) = Service Interval for normal driving conditions.
Example: Volvo has no transmission fluid interval but under the maintenance schedule it says, “Under normal driving conditions the transmission oil does not need changing during its service life. However, it may be necessary under adverse driving conditions”.
Using My Formula: 50,000 Miles (80,000KM) under adverse driving conditions means the fluid is actually good for 100,000 Miles (160,000KM) if driven under normal driving conditions.
This guide below shows that the “life” of transmission fluid is actually based on Transmission Operating Temperature.
Regular Normal Driving Temperatures:
175°F to 195°F (80°C to 90°C) = 100,000 Miles (OEM Volvo: 160,000KM) (AMSOIL: 320,000KM)
Racing Temperatures:
215°F (101°C) = 50,000 Miles (OEM Volvo Severe Service 80,000KM) (AMSOIL: 160,000KM)
250°F (121°C) = 12,500 Miles (AMSOIL: 38,000KM)