Realizing synthetic oil is not a cooling fan -
nor a radiator... but does it affect engine temp
noticeably? Sprcifically, does the engine run cooler?

 

No

 

Have to agree with Apeiron. I have tried synthetic oil several times on several different cars over the years and never saw any difference in cooling, performance, oil change intervals, nothing. I usually run my engines until they are too tired to keep going and have not seen a difference with longevity issues either. Maybe there is but I have not seen it yet.

 

Chuck, if you are thinking of making the switch to synthetic oil from conventional, keep in mind many on this site have had engine issues after the switch. They involve engines with some miles on them that start smoking after making the change. It seems the synthetic dissolves some of the deposits and sludge around the valve seals and guides and lets oil seep down into the combustion chamber. Just wanted to put that out there for you if you are thinking of making the change. I was until I read the posts about smoking. I just quit after 42 years.