[jato]

The car in question is a 1999 Sable Duratec, my sister-in-law's. I was wondering how effective the "finned tube" external trans cooler is? I know it doesn't hold a candle to the gen2 SHO cooler I have installed on my '06 Taurus, but for a easy, lightly driven car, is it worth upgrading?

 

[sheila]

A stacked plate one is much more efficient.

 

[KhanTyranitar]

The problem with tube and fin coolers is the heat has to transfer tot he walls of the tube, and from there to the fins, and from the fins to the air. The transfer between the tube and the fins is poor because the contact area is limited. A stacked plate cooler, the tubes are the fins, so the transfer is much more efficient. This means even a small stacked plate cooler can outperform a much larger tube and fin cooler.

 

[egiroux]

All of this is true. I have a fairly small tube and fin aux cooler and it gets the job done (I measured the temps) for a stock application. Depends on your needs.

 

[DLC360]

If you consider that most taurus and sables have that finned tube cooler and most have or will have trans problems due to heat, its not a good enough cooler. That cooler may work for highway driving, high flow rate of fluid and good air flow. City driving though is where the heat builds up and kills the tranny. Stop and go driving, low air flow and a slower rate of fluid flow will casue the heat build up. That tube gets so hot, it wont cool the fluid while your sitting in traffic. Think about your radiator and the electric fans. While on the highway, your water temp runs lower and your fans dont come on, in the city, the fans run most of the time to keep things cooler.
A car that is mostly a city driver is in greater need of a good cooler than the one that is always on the highway. My opinion, un hook that finned tube and put in a good trans cooler ASAP to save the trans while you can.