So I was going to change the fluid/filter, but as I started reading about, some people were advising against it on higher mileage cars. They said the detergents in the new fluid may clean out some deposits and possibly cause leaks/failures.

I have a 2000 Focus w/ 105k miles, and a 2001 ZX2 with 42k miles. What do you think?

 

you guys are worthless.

 

Go for it. I would rec'd doing a flush though instead of replacing just your filter and pan gasket. Use a good fluid like the valvoline max life atf, it will help prevent some leaks with it's additives. Flush will get out closer to 95% whereas filter and gasket will do like 35-40%