I've posted the below on another forum and haven't had much response. I apologize if this has been discussed ad nauseum here but a search didn't find quite what I was looking for:
"A couple of questions have come into my head over the last couple months since the Camaro has left the garage.
a) What oil pressures are "normal" and "optimum" for our LLT's at load and idle? My oil pressure gauge spends most of its time in the upper 1/4th or 1/5th. At 70mph cruise it's at appx 45-50. Even at idle after an hour drive it only barely drops below 30psi.
b) What is the pressure that initiates by-pass for the LLT? If I'm running such high psi would I be better off switching to an XW-20 to have higher flow for the same pressure which would potentially aid my engine at high rpm. This is assuming that adequate pressure is generated at low RPM.
c) Other than cost (by necessitating a synthetic oil) why would anyone use a 5W-XX instead of 0W-XX? They operate the same at running temp but the 0W-XX is thinner at start-up.
To start some discussion, a quote from BITOG:
"The best way to figure out what viscosity of oil you need is to drive the car in the conditions you will use. Then use the oil viscosity that gives you 10 PSI per 1,000 RPM under those circumstances. For some reason very few people are able to get this simple principal correct. I cannot explain further... You should use whatever it takes to get 75 PSI at 6,000 RPM during the lifetime of the engine. This formula works in all situations.
Some people have tried this and occasionally get a somewhat low oil pressure while at idle. This is fine. There is no stress on parts at idle, the smallest oil flow will do the trick. It is at higher RPM where more BHP is produced. This is where we need the flow. Remember that Ferrari uses 75 PSI at 6,000 RPM as the place to test your oil viscosity needs. If your oil gives this value under your driving conditions then your lubrication system has been maximized. Period."
By applying the above I'm at more of a 20-25psi/1k rpm prior to reaching the max on the gauge. Obviously I ask above where the by-pass kicks in as that is where you reach constant pressure regardless of rpm.
Thoughts?"
"A couple of questions have come into my head over the last couple months since the Camaro has left the garage.
a) What oil pressures are "normal" and "optimum" for our LLT's at load and idle? My oil pressure gauge spends most of its time in the upper 1/4th or 1/5th. At 70mph cruise it's at appx 45-50. Even at idle after an hour drive it only barely drops below 30psi.
b) What is the pressure that initiates by-pass for the LLT? If I'm running such high psi would I be better off switching to an XW-20 to have higher flow for the same pressure which would potentially aid my engine at high rpm. This is assuming that adequate pressure is generated at low RPM.
c) Other than cost (by necessitating a synthetic oil) why would anyone use a 5W-XX instead of 0W-XX? They operate the same at running temp but the 0W-XX is thinner at start-up.
To start some discussion, a quote from BITOG:
"The best way to figure out what viscosity of oil you need is to drive the car in the conditions you will use. Then use the oil viscosity that gives you 10 PSI per 1,000 RPM under those circumstances. For some reason very few people are able to get this simple principal correct. I cannot explain further... You should use whatever it takes to get 75 PSI at 6,000 RPM during the lifetime of the engine. This formula works in all situations.
Some people have tried this and occasionally get a somewhat low oil pressure while at idle. This is fine. There is no stress on parts at idle, the smallest oil flow will do the trick. It is at higher RPM where more BHP is produced. This is where we need the flow. Remember that Ferrari uses 75 PSI at 6,000 RPM as the place to test your oil viscosity needs. If your oil gives this value under your driving conditions then your lubrication system has been maximized. Period."
By applying the above I'm at more of a 20-25psi/1k rpm prior to reaching the max on the gauge. Obviously I ask above where the by-pass kicks in as that is where you reach constant pressure regardless of rpm.
Thoughts?"
