CheapXJ said:
larger radiator = more coolant capacity = cooler engine. period.
anything else is pissing up a rope.
A bit overstated it's not nearly that cut and dried. Why do you have hood vents BTW?
lowering the temp of your thermostat does NOTHING.
Wrong, thermostats sole reason for existence on an engine is to keep X amount of heat inside the engine so that it doesn't run too cool.
Too cool = inefficient. period.
electric fans are a bandaid, and you don't get extra power,
Parasytic drag on an engine is a physical fact of reality, lowering drag = more power. Typically you can expect 1 to 5 HP increase just from eliminating a belt driven accessory.
you get a slight increase in throttle response in exchange for a horrendous load on your charging system. Most stock jeep alternators can barely power the single stock fan and you'll just be changing the alternator more often.
Horrendous sounds very impressive... actual amps drawn compared to what the charging system is putting out, and what it can handle would be even more impressive.
With an auxilliary electric fan ALREADY DESIGNED IN that must run when the HVAC blower is also going; I would say that the charging system can more then handle an electric fan.
My Electric fan + Aux OEM electric fan, have been running great for 40,000 miles (give or take a few) on what apears to be the original OEM alternator, or OEM replacement... which would have 240,000 miles on it... I'm also drawing "horendous" Amps from my Sub, 500wat amp 4 speakers, CD changer, AC, 7 Autometer gauges, fog lights, etc.
vents help MOST when moving at slow speeds. sometimes mine made it hard to see when wheelin on hot days..
Probably true of vents that are positioned towards the front of the hood. Cowl vents have the most effect at higher speeds when the low pressure at the cowl allows air to be sucked down under the vehicle, on my XJ this means the open driver side cowl (the passenger side is sealed to the air intake box) is sucking cool air down into and past the intake, header and down pipe. Dramatically lowering underhood temps (about 20 degrees) when driving 30 MPH or more.
any slower and the heat raises up out of the opening cooling things off more than the normal hood configuration (about 10 degrees average), about half as much as 30 MPH+