Quote Originally Posted by DD977GM2 View Post
That is very debatable. I have driven cars 150k without ever changing the tranny fluid and
really depends on the maker. If American, stick with the 50k rule. Change all fluids every 50k.
If foreign made like Toyota (the best) Change every 75k to 100k.

They are trying to upsell to women because most women have no clue about vehicle maintenance.
There is no debate at all. I crossed a freeway when I was 6 and did not get killed, but I wouldn't let my 6 year old do it.

I spent several years as a lab tech in an oil analysis lab and the science is irrefutable. Transmissions at sea level last longer due to lack of hills, but primarily better cooling due to denser air. The auto makers "barely" give enough cooling for them (even your beloved Asian brands). Now, if you have a heavy duty tranny cooler, or you only drive under 55 on the flat, probably not an issue.

Transmission fluid has an additive package, and it breaks down, on average, at about 30K in petroleum based fluids. When the pacakge breaks down, wear increases, but more important, the seals loose the conditioning and the propensity to foam increases. "Flushing" is generally a bad idea and in most transmissions, changing the filter is an every other time deal. If one is so inclined, you can replace the fluid with synthetic and a new filter and go about 100K from there. Some high end vehicles (some Amreican, but mostly European) come with 100K rated synthetic (usually green) tranmission fluid which is phenominal.

But, since we live in America still, you are free to beleive anything you want.