Should I change my transmission fluid (for possibly the first time) at 121k?

[808uxi]

I bought my 2016 Fiesta S about a year ago and have been going down the list of maintenance items and after doing all the basic maintenance first, i'm left here with this question. I never got any sort of talk at the dealership about what maintenance had been done before in the previous owner's hands so I'm left in the dark if the previous owner had done changes at the common recommended intervals (30-60k). In the owner's manual it says to do it every 150k but I'm very doubtful in how they arrived at that number. If it were to be the first change how bad would that be for the transmission?

 

[SyntheticAtmosphere]

2 cents for free here...

Do you have a manual or an automatic?

If manual...change the fluid. If you dont know the service history, changing it wont hurt anything. In most cases with manual, there will be an improvement.

If automatic...If your car has lower mileage or you can quantify the previous owners service history and service has been done regularly, changing the fluid should be fine.
However........If your car has higher miles and you cant quantify the previous owners service history, dont change the transmission fluid. Adding new fluid with a full detergent package can cause buildup in the transmission to work loose and plug up passages down the line. Leading to failure...seen it too many times.

 

[808uxi]

Yeah it's an automatic and can't find out anything in the cars service history so I think I won't do the change, thank you for the 2nd opinion.