Oil Pressure with Synthetics

[Cracker65]

I'm on my 2nd oil change using Mobil Delvac-1 on my 2003 DA and it seems like my oil pressure, via the OEM gauge, runs a bit lower than with dino oil. At idle the needle is midway between 0 and 30 psi - and it doesn't go over 60 psi until about 65 mph. This is with the truck light. When towing, or otherwise under load, the pressure goes up to 60 psi at a lot lower speed - as might be expected. I'm just wondering what others have experienced???

[LanduytG]

Nothing to worry about. Some have seen this and some have not. Synthetic is less resistant to flow so you you can see a bit less pressure.

Greg

[Jim Brzozowski]

Sounds like its right where it needs to be to me. Less resistence to flow equals less pressure to pump same volume and requires less energy drain on the engine. Some waste horsepower trying to pump too much pressure. Its not necessary. High volume is the key. Rule of thumb from ole Smokey Yunic was that all you need hot was 10 psi for every 1000 rpm your turning. The racers start to have a serious problem trying to make 100 psi at 10,000 rpm going through the speed traps with the large diameter crankshaft journals nowdays. A DMAX should run forever on 60 psi. IMHO

[madmatt]

yeah they don't require a whole lot of pressure like pollock mentioned. I had a customer drive from FL to Southern IN w/ about 30psi and fuel pouring out his crankcase vent. He come to us and complained about low fuel milage then went on to mention the oil pressure problem.

[Brian DMT]

I agree. My DMax dropped idle pressure from 40 psi to about 32 psi when I switched to synthetic, and that kind of drop is very normal: because the synthetic oil molecules slide over each other easier, it takes less pressure to get the same flow rate. In actual use, we get a combination of higher flow AND lower pressure, which is fantastic. It also means you have quicker oil supply at engine startup, for reduced engine wear.

[TRPSHOOT]

I'm running synthetic Rotella and asked my dealer the same thing. My idle is one mark below 30 and the dealer stated the same things previously posted.