You might check here.

http://www.jeepstrokers.com/forum/vi...t=3432&p=30506

Phoenix in August you could run almost straight water which would help bring your temps down. Maybe a 90 to 10 ratio so you have some rust inhibitors from the antifreeze. Antifreeze has poorer heat transfer properties then water, meaning water will take heat from the motor better.

Another thing to consider is a restrictor. It sounds like it will hurt, but it actually helps slow the flow which means more heat is transferred from the block to the coolant and in turn longer for the coolant to cool in the radiator. Got the info from this guy and it should help regulate your cooling (less drastic ups and downs).

http://jeep-xj.info/HowtoRadiatorRestrictor.htm

 

Best of luck to you!! my cherokee has sure had some troubles! i think we are running okay now! i think i am having just as hard of time adjusting to the heat.. its killer! the jeep and i look forward to a phoenix winter

 

It actually snowed in Scottsdale last year! The start up company I work for is based out there, so I'm going to be doing 2 weeks in Cali and 2 weeks out there. Looking forward to finding some good desert wheeling places.