Howdy All..

I've searched the forum on the topic of the operating temp of a 617 engine, but want to verify that I have this right.

My '85 SD temp gauge lies a few clicks (1/8 of an inch approx.) below the 100 C mark when it is warmed up. In the city and on the highway the temp generally stays at this level.

However, when I climb hills the temp rises to exactly the 100 C mark. Also, at 75mph + speeds, the gauge rises to right below the 100 c mark. When the rpm's drop to "normal" the temp gauge drops right back to its steady state of a few clicks below the 100 C mark.

From what I've read, it seems like this is perfectly acceptable. But, I can't help but think that higher operating temps might be a symptom of less than optimal performance. Any advice or thoughts much appreciated.