I'm thinking about running 15w40 as well and I do get some crazy looks lol

 

Note from DJ
98 Oil Pressure Sending Unit Trouble with test
https://www.cherokeeforum.com/f2/oil...rouble-173601/
OP by EagleXJ on 7-6-13
So I was replacing my oil filter the other day and snapped the oil pressure sending unit. I went to advanced auto and got a new one but it didn't work. Took it back and got a different one and this one doesn't work either. I unscrewed it and turned the engine on and oil blew out so the sensor is sure getting oil and I also gave power to the plug and that moved the gauge so the electrical from the sending unit to the panel is good. What could be wrong?
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See Post #14 by CCKen for gauge test procedure
I don’t know if this test procedure by CCKen will work on a 97XJ or not He was giving this information with a 98XJ

Or see if you can find something like this in your location at a building supply sales outlet or auto parts sales outlet.
It must have 1/8 in. NPT or National Pipe Thread; so that you can just remove your existing sensor and the gage will screw in to the opening you removed the sensor from. 0-60 or 0-80 psi will also be OK.
This will give pressure reading that is fairly accurate if you want to know for sure what your oil pressure is; if you can find one this in your location.
Pressure Gauge with 1/8 in. NPT or National Pipe Thread
Range of 0-100 psi/kPa
Price is @$9.30 at my local Home Depot