HI HO said:
Sorry, I still don't buy it.
Why wait, I'll just type it out:
1) The transmission temps should never be below 175 degrees F.
2) For ever 20 degrees over 175F your ATF is, it will break down 50% faster. So if it will last 60,000 miles at 175F, then at 195F it will only last 30,000 miles. (...only 15,000 miles at 215F)
3) Honda Prelude SS Auto transmissions generally run at about 230F or so.
4) The coolant is generally at 195F to 210F.
5) The coolant cools the ATF and is also warmed by the hotter ATF fluid.
6) Synthetic fluids are generally better at thermoconduction. Therefore, they are better at transfering heat more efficiently.
7) Using an external transmission cooler allows for better cooling of the transmission. There is, however, a point at which the heat traveling off the cooler would warm engine coolant as much as if it were still passing thru the OEM ATF cooler. For that to be the case it would have to be a very large surface.
8) Due to the lower proximity of the aftermarket cooler to the engine cooler (radiator), the engine coolant is not warmed as much as it would be with the OEM configuration.
It pretty much makes sense.