Not sure I want to go into an argument. I was trying to illustrate that an oil cooler is more or less relevant depending on the use which is made of the car. Long hours at high speed make it relevant, 70 to 80 mph speed limitations and improved oils which keep their lubricating capabilities at higher temperatures and a lower rear end ratio make it less relevant. I thought the W126 was a good illustration of that evolution.

Cliffk: I believe the tall grid 280 rad with oil cooler would be the same overall size as the original 250SE coupe radiator. I"m not sure they increased the thickness of the core bank on the water side to compensate for the loss of surface area taken up by the oil cooler. You should compare both cooling systems total capacities. I don't have the one for the 250 but the 280 including heater is 10.3 lts according to the w/shop manual. They don't distinguish between low and tall grid.