The Boating Forum - Gaining RPMs with Penzoil Full Synthetic

I recently switched from Yamalube to Penzoil full synthetic in my twin 150 HPDIs. For the 4 years I have owned the boat, I always run the boat full throttle in the creek leading to the dock. Both engines always ran 5300 RPM (or 5400 RPM if the boat was lightly loaded) without fail for the past 4 years. Sinced I switched to Penzoil full synthetic, I am consistently getting 5500 RPM (some times 5600 on the starboard engine) when I run wide open throttle in the creek. I initially thought the first time I saw 5500 RPM that the engines "were having a good day". I had never seen 5500 RPM before. After I saw I was consistently reaching 5500 RPMs, I have to wonder if the synthetic oil was making this difference. Has anyone else had a similar experience with fully synthetic two stroke oil? I am not trying to promote full synthetic oil or bash Yamalube. I am just courious if anyone else has had a similar experience when switching to full synthetic 2-stroke oil. The engines have 450 hours each. 2002 150 HPDIs

Thanks!

Never seen that but I did have a big block chev suburban that picked up 2 mpg when I went to full synthetic.

Maybe they're finished now with the break in .
My Suzuki 140's started running noticably better when they got to about 350 hours.

I had a Super Viking with 300hp motor (airplane).... When I got it, the owner was using synthetic oil... I changed the oil the day it got it nad replaced the synthetic oil for petroleum base oil I had on hand... WHen I went out for the first flight the idle was so slow by 150 rpm the engine would stall (it did not occur to me why at that time as the airplane was new to me)... So, the mechanic adjusted the idle... Next oil change I decided to go back to the synthetic... Flying it with the new oil I noticed the idle was high (engine oil still cold) but took off anyway... Coming back for a landing (oil now hot) I had the brakes red hot getting it stopped as the engine was now idling way high... Finally, it dawned on me what was going on... Used synthetic oil only after that... It has to be more efficient...

denny-o

Thanks for the reply guys. It looks like the synthetic oil is also helping on the carbon build up on the plugs. I pulled the plugs expecting to see the same buildup I always see (atleast on the bottom two cylinders), but they were noticeablly cleaner this time around. I'll check them again later this summer and see if they stay clean.