[HarryD]

Pete,

Some thoughts on oil temperature by Steve Weiner.

Originally Posted by Steve@Rennsport

If I can add to Dan's post,....

JMHO,.......Thermostats open between 180-185 degF and I like to see these engines run between 190 & 220 degF. The 220 mark is the tiny hash mark on the gauge face directly across from "Normal" on the graphic. 248 is too damned hot (paraphrasing my buddy Bruce Anderson) and not conducive to maximum engine longevity.

Modern synthetic oils function well above 275 degF, however the propensity for oil leaks rises exponentially when the engine operates in these high temperatures. For that reason alone, I like too maintain operating temps below 200 to maintain the integrity of all the gaskets, seals, and O-rings.

Performance really begins to fall off when oil temps rise above 210 degF so thats something to consider due to high cylinder head temps and reduced volumetric efficiency.

My advice to "ramonesfreak" would be to use a 15w-40 in hot weather and at those temperatures, leaving the lighter oils for water-cooled cars. Overfilled oil systems result in high oil temps so make sure you are making any dipstick decisions at operating temps (above 190 degF).