amsoil dominator 5w-20

[MikeyRHD]

just wondering if anyone is or has used this oil in their car?

I am going to use either this or dominator 10w-30. Considering my oil temps are never high for extended periods that the 5w-20 will do the job better but without checking to see if oil pressure is correct as per the service manual (65psi at 6000rpm at 80c) I won't know for sure, unless someone has already tried it out and can tell me their results

[frankiman]

10w-40 or 15w-40 would be better suited for Rb engines

[Rblove26]

could you explain why frankiman? i've been trying to decide what to run next year. i currently am running 5w30 and was gonna switch to 10w40 or 5w40 (if available). plans have changed this year tho and im going to be rebuilding my rb25 this fall so i dont know if i should stick with 5w30 now cuz all my bearings will be new. or is 5w40 still better? thanks

[MikeyRHD]

ya I would like to know what you based your decision on as well, what are your oil temps typically? or your oil pressure?

At 100c a 5w-40 oil is about 13-14 cSt and at 80c it is about 23.3cSt which is quite a bit higher than lets say a 10w-30 which is about 10-11 cSt at 100c and 18.5cSt at 80c (I'm using 80c since that is what the service manual uses for checking oil pressure). Again without checking to see what oil pressure actually is as specified by nissan I can't actually say which oil is more appropriate. Also my oil pump is stock so that is why I am going by the factory specs.

Personally I would always try to shoot for an oil that has as low a first value as possible (ie a 5w-40 preferable over a 10w-40 or 15w-40) as I do almost all city driving. I would say though if you and warm up properly then having a 15w-40 isnt really an issue, but for city driving its not ideal.

[Black BNR32]

i run dominator 15-50 and my pressure is about 1 bar higher than recommended