If you have your a/c running -
1) does it waste gas?
2) if it does waste gas, does it waste the same if on 1 or on 4?
3) When do you know when you need to re-fill your frion (sp)

 

To answer:

1) It uses up more gas, because the engine must work harder to run the AC compressor. Whether it is a waste or not, you decide. To me, it is not a "waste" if its 90+ degrees to stay cool and dry inside the car.

2) You will probably use up a little more on 4, since the AC compressor automatically cycles on and off to keep the air within a certain cold range (even on the non climate control models)

3) You need to refill your refridgerant (R134a) when your AC is not as cold as it used to be - keep in mind that even a fully charged Maxima isn't that cold when the AC is working perfectly - thats my experience when compared with other cars such as Toyotas (which have COLD AC)

 

Actually crusing at highway speeds (60+MPH), the wind resistance and air turbulance caused by your windows being open will cause more drag on the car then your A/C compressor.

Around town it's a completely different story. I'd rather be comfy regardless of the price of my fuel.

 

1) Correct
2) When the blower motors is on 1 or 4, indirectly will not effect gas usage. Yes the a/c comp will cycle more or less depending on the pressures.
3) If your system is completely sealed, you should never have to refill your freon. Re-filling freon indicates you have a leak somewhere in the system.

 

ohh, alright I get it now....so what about the heater, same thing? does it use up gas too?

 

No, heater does not effect fuel usage like the AC system

 

Tell me about it, I'm starting to really hate this about my Max, and it hasn't even started to heat up here (gets up to 109+ in peak summer months) I'm going to Die this summer, not to mention that the AC on my car seems to drastically affect the gas usage.

 

i guess I have a leak some where then... I refilled the freon last year around this time... now when I turn on the AC... it doens't even blow out any cold air... it blows out room temp... meanin if its cold... then it will blow out cold air.. when it's hot.. it will just blow out hot air.. but not like the heater...

if there are no leaks.. is there another reason for this to happen?

 

In short, yes there could be other reasons for your faulty ac system from mechanical to electrical. When you add freon does the ac works correctly, if so find and repair your leak. The ac system has pressure switches to cut off the compressor when the pressures get too high (so not to blow the system) or low (to save the compressor)