Amsoil 5w30 lower oil pressure

[Sixspeed]

I have just switched my truck over to amsoil 5w30 HDD. Also installed a dual by-pass system. Now my oil pressure seems 2 to 3 lbs lower at Hwy speeds and 4 to 5 lbs lower at idle. Any of you guys out there that have switched to 5w30 have this same type of oil pressure drop.



Thanks, Les

 

[WestTN]

lower pressure

You are replacing 15W40 with 5W30. It is thinner, so the pressure will be lower.

 

[TwoSlick]

Les,



Oil pressure is a function of oil viscosity, so of course an SAE 5w-30 or 10w-30 is going to give you slightly lower pressure than a 15w-40. For comparison the viscosity of the Series 3000 is about 11. 5 Cts (centistokes) when tested at 210F, whereas the 15w-40 Marine oil is 15. 0 Cts at 210F. I think you find the 5w-30 runs a bit cooler than a 15w-40, so the difference in oil pressure is not as great as this difference in viscosity would suggest. The general rule of thumb is that you want at least 10 psi/1000 rpms of engine speed to maintain full film (pressurized) lubrication in the bearings.



The dual remote kit is hooked up in-line, so you are not shunting off any oil flow and pressure should remain the same. There is some slight restriction in the oil lines that would account for a pressure drop (especially if they are long), but I think it would be minimal.



TS

 

[lschultz]

I run the 5w30 and I do not notice any difference on my guage at idle same thing with my sons 99. But I've seen posts that people who run the bypass do run slightly lower oil pressure. Nothing to worry about. Do a search on this and you'll find the info.