I use Rotella T6 (synthetic) 5w40... 18psi idle hot, 50psi cold Love the stuff, holds up to the heat really well.
Used to use Valvoline diesel blend 5w40
In addition to being designed for high heat turbocharger conditions, diesel oils are high in zinc, which is good for additional protection in case of detonation and high horsepower situations that can beat up connecting rod bearings.
Buildin' n' Boostin for 08' - Alex Richards
Surprisingly nobody has asked where you are taking these oil pressure readings from and what type of gauge setup is giving you this reading........ So lets start there. I have all the galley points pretty well mapped out under all conditions and temperatures.
Mobil 1 is my personal favorite but the debate as to which is better pretty much spans the timeline from when oil was first discovered so good luck there.
If I were to switch it would likely be to Eneos as well. Can be purchased through any NAPA.
ASE Master Certified Automotive Technician
Alan, i am using a digital gauge with and electronic sender and the port on the driver side of the head. all oil look fine colorwise, doesnt look burnt but thins out really fast!
Mine sits in that range once warmed up in the heat out here too. It's dramatically altered by the ambient temps here from that particular port. Could it be that the pressure drops you have been seeing are coinciding with the increases in ambient temps we have been seeing here? The high pressure areas of the block do not vary as wildly with ambient temps as do the head pressures on the exhaust cam port.
ASE Master Certified Automotive Technician
why yes alan they have been changing as the temp rises. do you think a change in oil would help? or maybe a change in location of the gauge, or should i just get used to it being so low?
If you are just reading oil pressure for the sake of your engine I would recommend sampling it from the center oil galley on the left side on the block (facing the front of the vehicle) directly under the intake manifold (Just below the left balance shaft). Depending on what gauge you are using and the sender associated with it you may have difficulty fitting the sender under the SCer intake manifold for a direct galley sample. You may need to do a remote hookup but again I have no idea what gauge setup you are using as some of the digital ones have small senders (AEM for example). Another thing to keep in mind is that your average 2 1/16" oil pressure gauge is usually limited to 100 psi and you will see as high as 125 on that port when cold. There are several gauge companies out there that have oil gauges and senders that will go over 125psi.
Me personally I take readings from that port and the head port simultaneously but I monitor the head port in order to keep an eye on when the pressures drop to a level I feel comfortable with for turbo safety
I would continue running the same 5w30 as you have been except perhaps dump the Penzoil. I have never been a fan of how liquidy it is right out of the bottle but again that's another debate that will likely never come to any real resolution.
ASE Master Certified Automotive Technician
I've run mobil 1 for years with no issues, only pressure drop I'll see if is if I hot lap the car 4-5 times at the track, then I lose about 5-8 psi at idle.
Mind you hot lapping a car 4-5 times isn't exactly easy on it.
I take my pressure reading from the oil filter housing, so my oil pressure is off the charts, it buries my 100psi gauge at anything over 4000rpm when hot.
I really should move it to after the oil filter, but I just have been to lazy, if the oil pump goes at least I will know right away!
