Does using Duel A/C hurt your MPG?
- Thread starter savesheep
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00void
New member
i would ASSume it's just one fan + condenser but with cut-offs in the piping to allow either cold or hot fluid through the system for the air to blow out.
anyway, from what i've read/heard, running AC won't affect gas mileage given the sophistication of engines made today (or something along those lines).
while i don't have dual-zone AC in my T4R, i haven't noticed a decrease in mileage using it in my Pathfinder.
anyway, from what i've read/heard, running AC won't affect gas mileage given the sophistication of engines made today (or something along those lines).
while i don't have dual-zone AC in my T4R, i haven't noticed a decrease in mileage using it in my Pathfinder.
mole177
New member
i disagree. using AC def uses more gas vs not using the AC. it may not be a significant amount, but it def uses some gas.
when you hit the a/c button the compressor turns on which makes the idle go up a tad when sitting at a stop. you just might not feel it when you're in motion.
when you hit the a/c button the compressor turns on which makes the idle go up a tad when sitting at a stop. you just might not feel it when you're in motion.
this should add some fuel to the fire.
Mythbusters tested this myth:
Running a car with air conditioning on is more fuel efficient than running with the windows down.
partly confirmed*
Tests were performed under varying conditions (55 mph versus 45 mph). The 55 mph test used a computer to estimate fuel efficiency based on air intake, not actual fuel consumption, and showed A/C was more efficient. The 45 mph test consisted of running the tank until it was empty, and showed open windows were more efficient.
*Because the original tests were inconclusive, this "urban puzzle" was revisited in episode 38: It is more fuel efficient to use air conditioning when the car is traveling approximately 50mph or more. Otherwise, windows are more fuel efficient.
Mythbusters tested this myth:
Running a car with air conditioning on is more fuel efficient than running with the windows down.
partly confirmed*
Tests were performed under varying conditions (55 mph versus 45 mph). The 55 mph test used a computer to estimate fuel efficiency based on air intake, not actual fuel consumption, and showed A/C was more efficient. The 45 mph test consisted of running the tank until it was empty, and showed open windows were more efficient.
*Because the original tests were inconclusive, this "urban puzzle" was revisited in episode 38: It is more fuel efficient to use air conditioning when the car is traveling approximately 50mph or more. Otherwise, windows are more fuel efficient.
Mole - just to clarify - you are right in that the engine speeds up as a result of turning on the AC, but it is not a direct result. The AC increases the load on the engine (takes power to turn the compressor) whcih would actually decrease the engine speed (RPM's) if it were not for some mysterious intervention. When the AC comes on there is some solenoid (how it used to be done - not sure how it happens anymore) that increases the engine speed to offset the extra load. It is likely done now through a program in the engine computer / mapping. Yes - it does require more gas but I would venture to say a negligible amount.
ImOnAPlain51
New member
I've also heard this myth, not sure if it's true or not....but having the A/C off and your windows down uses more fuel than using A/C with your windows up. The reasoning is that you lose your aerodynamics with the windows down and the cab acts like a wind scoop. Haven't ever tried it out, I'd think it'd be neglible either way.
