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Jim Adney wrote: With the car standing still you would get some extra heat rising up from hot heat exchangers, or J-tubes, but I don't think this will add much real heat load to the engine when it matters (when you're moving and the engine is working hard.) I have to disagree with Jim on this one (I can't believe I actually said that 8^)) sort of. I agree that with engine "generates" the most heat when it is moving and under load (such as climbing a grade), but it also has the most help from airflow to remove that heat. I did a bunch of testing in Arizona a few years ago to look at undercar temperatures. A typical test location such as a frame crossmember near the exhaust would have a steady state temperature of 210 F under normal driving (flat, 55 mph), a steady state temperature of 330 F under heavy load driving (climbing a grade at 35 mph), and a short duration spike in temperature of 450 F immediately after the car was stopped and still idling. This is part of the reason why stop and go traffic is so hard on cars. Later, John Jaranson '71 FI Auto Fasty (Jane) http://hometown.aol.com/jaransonT3 ------------------------------------------------------------------- Pitch in! Send your pledge of support! mailto:support@vwtype3.org