Anybody dyno before and after with regular oil and then synthetic oil?

 

I don't think that there would be any difference. Just wear properties

 

I seen this on I think horse power tv awhile back they changed motor oil,tranny,and diff over from reg oil to full synthetic royale purple and got 10 rwhp

 

Yah I remember that wasn't in on a 99-04 Mustang GT?

 

for just the engine, someone told be 5rwhp? Is this about right?

 

The main reason manufacturers use a low viscousity synth oil in many new cars is for the increase in mileage to help get them by the government's corporate average fuel mileage requirements. Yes, either low viscousity and/or synthetic oil increase mechanical effeciancy. Some engine builders use something like a 0W-10 weight synthetic when dyno testing for better HP/TQ advertising numbers.