Originally Posted by getrdunn

I can't begin to tell you how many years I've used Napa oil which I always thought to be valvoline. I Run engines hard with minimal problems over the years. It's interesting to hear some of the post regarding sythetic but yes perhaps coincidental. I was continplating changing over to amsoil sythetic in fresh 496's. The machine shop I use highly recommends the zinc addative and swears by it especially with today's oils especially with flat tappets.

Originally Posted by ROTAX454

When I talk about using AMSOIL, I did not want to give anyone the idea that a ZINC additive was in the AMSOIL motor oil. Yes, they do have additives. But refer to them as "proprietary". Here is some good reading on not only the Joe Gibbs oil, but some good baseline information on motor oils and usage.
http://www.superchevy.com/how-to/add...en-racing-oil/

Originally Posted by imartin

So, ordered 4 gallons of OEM Merc 25W-40 4cycle oil for oil change on my two 525efis. Open the box, and they shipped 2 gallons conventional as ordered, but mistakenly sent 2 gallons of 25W-40 4cycle Synthetic Blend.

My question is, while the manual only refers to conventional, would the synthetic blend mixed with conventional be a mistake? Blend in one engine and conventional in the other?

I prefer to follow the manual to a T, but wanted to bounce it off my OSO buds!

Thanks....

Originally Posted by HyFive578

I used the synthetic blend for a while and then started to have issues with lifters. But can't say for sure if the oil was the problem. If you ask opinions on oil, you will get 1000+ different answers. Here's 1001.. I now use Valvoline VR-1 20W50 conventional in my 525EFI's and change oil and filters religiously at 25 hours.

Originally Posted by vintage chromoly

Where the hell is Borgie when you need him?

Originally Posted by mummaiv

What filter are you using?