is this oil okay to run in the cherokee gasoline engine?

 

Yes but I wouldn't pay extra for the 0w40 when 5w40 and 15w40 work just fine.

 

My information is you should use the oil with the lowest startup viscosity that you can afford lol

The reason for this is 0W synthetic gives the quickest lubrication on cold startup

cold startup is where most engine wear takes place

happy to be corrected on my logic

I use semi-synthetic 10W-40 high zinc, as lets face it, would I be driving around in a '96 Cherokee if I was rich ?

 

That may be true for newer engines. No way would I run a 0W in a Cherokee, or any other engine of that era. I would not go lower than 10W unless I lived in Alaska.

 

0w40 is the same viscosity as 15w40 once up to operating temp.

 

I use what was available when the motor was designed, conventional 10w 40

 

I would like to know how is oil pressure is with 0w-40 oil , and what oil he uses now and what the oil pressure is .

 

Oil pressure varies with the second number, not the first one - as long as the oil makes the advertised spec. So any Xw40 oil should make the same pressure at hot idle.

 

That's correct, 0w40 will have the same pressure at operating temp as straight 40w oil.

 

I've looked into the viscosity information and it seems to be the 0w would be best to reduce wear on start up. Right now I'm using 5w30 (rotella) and my oil pressure is perfect. I'll update here when I use the 0w40.

 

You're in Southern California running 0W oil? You realize that 0W oil is only at that low viscosity when under 32'F. That's for Jeeps in Maine, Minnesota & Alaska or for modern vehicles with "Advanced Fuel Economy Engines". In your warm climate, the difference in viscosity between 0W40 & even 10W40 is negligible.

 

Wouldn't 0W oil be less viscous than 5W or 10W even at 70 degrees F?

 

According to this rather lengthy source..Yes..go to Page 2 for a chart

https://www.bobistheoilguy.com/motor-oil-101/

An interesting read on the topic of motor oil, make up your own mind