Bringing this back TTT.

I've been doing a lot of reading on oil on Bob's site and agree that thinner oils and synthetics are perfect for automotive use, but there's not much info over there on real high hp offshore engines. In the past I've always used 20-50 or straight 50 dino oil (VR1) in my SC BBC's for marine use. Looking at my cold oil pressures has me rethinking this.

Thoughts on using 5-40, 10-40, 15-50 synthetics for these high HP marine applications???

Amsoil Z-rod 20-50 oil

I have used Merc's 25W-40 in all my marine apps for 30 years. 350s, 350 mags, 496s, 525s, even a Volvo Kaiser V-6 I had in school. Never an oil related problem. First the dino and now the semisyn. Just change it as directed and you'll be fine whatever good oil you choose.

Second the Amsoil Z Rod 20w-50.

Brad penn 20-50 for me.

This......http://www.amsoil.com/shop/by-produc...50-racing-oil/

+2

I was wondering why you choose to us the Dominator oil. I use the z rod oil 20-50. I wrote to Amsoil and told them my type of engines and the rpm i run all day. They responded and told me to stay with the z-rod oil. Just wondering.

This is just one of the reasons , read the last paragraph in these two articles . http://amsoilracing.com/index/News/2...om-marine-gn77 http://www.offshoreonly.com/forums/g...int-clair.html I'm sure the Z-Rod 20w50 is also fine to use .
This is what sold me !!!!! http://www.trustedoil.com/Mercury_52...e_Teardown.htm

Interesting information. Here is the question I wrote amsoil about my engines and the response I got. I can't figure it out...................

Amsoil. I have been running the 20-50 motor oil and also the z-rod 20-50 motor oil. I have a high performance boat with twin 509-500 hp each. I run all day at 3500 rpms and up to 5200 rpms. Would the dominator 15-50 oil be better for my application that the regular 20-50 oil Thanks.

Amsoil's response. Jay;

I would stay with the 20W50, either ARO or ZRF, over the Dominator Oil in this situation.

Byron Selbrede

Technical Services

AMSOIL INC.

ADDRESS: 1 AMSOIL Center, Superior, WI 54880

E-MAIL: [email protected]

PHONE: 715-392-7101

FAX: 715-392-3097