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Old 03-12-2010, 04:40 PM   #91 (permalink)
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Join Date: Feb 2010
Location: CT, USA
Posts: 544

RaceJeep - '98 Jeep Grand Cherokee (ZJ) 5.9 Limited
90 day: 13.62 mpg (US)
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My Jeep has a 2 speed electric fan. It comes on low when the upper rad hose hits 210* (about 213* on the gauge), and high when the lower rad hose hits 210* (about 220* on the gauge).

Therefore, in normal driving, when the fan is off, it's no different than being fanless. Based on how the fan cycles (engine thermostat is 180*), I could never run without a fan in the city. Even in 30* F weather, if I get stuck in downtown traffic for 6-8 minutes of slow speed movement, it'll hit 213* and kick the fan on. In the summer, I could never survive without it, plus the A/C wouldn't work well at slow speeds either. With the fan, however, it has no trouble keeping cool, and the fan isn't needed at higher speeds.

Part of it is that the 360 produces A LOT of heat. The factory hood vents on the Grand Cherokee 5.9 aren't for show, they were added because they had trouble keeping the prototypes cool. That's also why it is rated to tow less than the 318.

Call me crazy, but I actually try for mpg with this Jeep:

Typical driving: Back in Rochester for school, driving is 60 - 70% city
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