What should the Oil Pressure be under normal highway driving conditions for a 2002 XKR. Mine is running about 60 psi. When I first installed the RealGuage oil pressure sensor, it was running, about 70 psi but dropped to 60 psi after I did the lower s/c pulley and intercooler radiator upgrades. Does that sound right? It doesn't make sense to me that the pressure would drop because of those upgrades but it has been consistent.


Mark

 

Same oil?

Even if you did an oil change using the same oil, it may have been reformulated.

The oil could also be warmer as a result of the engine working harder with the
bigger lower s/c pulley.

Is there a calibration required with the RealGauge? It might have drifted.

 

Always used the same grade of oil. I can't say if the temperature is higher, I just don't remember what the temp was reading before the s/c upgrade. There was not much time between the RealGuage mod and the s/c mod. I guess with the s/c mod the engine could be working harder causing the temp to be higher. It's just that 10 psi seems like a big difference.


Mark

 

Both pressures are well within the normal range. I concur that hotter oil will lower the pressure.

There is no calibration for the oil pressure for RealGauge.

 

Thanks Steve, that makes me feel better.


Mark

 

In my distant past I owned Alfa's, which had both oil temp. and pressure gauges. It is not at all unusual to see a ten lb. pressure drop with higher oil temp when the engine is working harder.

 

Thanks, I understand the physics but had no reference regarding the magnitude. This makes me feel better too.


Mark

 

Rule of thumb is 10lbs pressure/1000rpm is okay for gas engine.

 

Hi.

Here are some numbers from "Engine Repair Course"

 

Also, as the oil ages in the engine its ability to maintain pressure will degrade (very loose wording for viscosity breakdown.) You'll probably notice less drop after your next oil change until it also ages. The spooky part is when it used to idle at, say, 30 psi and later idles only at 10. To be honest, that's how I gauge when to change my oil but I don't recommend the method to others.