Ac and gas mileage

Moparty08 · Post by **Moparty08** » Sat Jul 04, 2009 1:26 am

Ok i'm from New Hampshire so I like the cold. I just got ac in my car finally but now i'm wondering what kind of effect it will have on my mileage. I think this should go in this section but if not then someone can move it.

I'd like to use my ac alot without much effect on my mileage. I know people have used a high capacity alternator or w/e and even an extra battery for their sound systems. It creates less strain on the electrical system. I was wondering if the same principle could be used for the ac system. Using a high capacity alternator could I sorta cancel out the strain on the electrical by adding more power?

Also i've seen thin batteries before. I 've been trying to find some with no luck. You can fit two in the space of a normal one. Has anyone else heard of this or am I crazy.

And where could I get a better alt. Thanks a lot guys.

Dylan-00Blue · Post by **Dylan-00Blue** » Sat Jul 04, 2009 12:34 pm

a/c pwns milage it will get shitted on so hard leave the a/c off and use the flow through vents even opening the windows kills milage

excon · Post by **excon** » Sat Jul 04, 2009 10:24 pm

pt alternator is a little better than stock. You're on your own with the rest though.

Moparty08 · Post by **Moparty08** » Sat Jul 04, 2009 11:16 pm

Shit man woo i'm feeling good 3 shots of jager and some other shit stuff. happy 4tyh dudes. so yeah i'm gonna geep looking for theat other shitthe th for the batteries like those skinny ones. woooo i'll looke for a pt. Is it too hard to install and is it much differenyt than aneon'sone

excon · Post by **excon** » Sun Jul 05, 2009 2:15 pm

ITSANSS · Post by **ITSANSS** » Thu Aug 27, 2009 11:27 pm

The more you add to your car, the less mileage you will get.

Two ways to cool off in a vehicle are rolling the windows down and installing an air conditioner.

Both of these methods cause a decrease in fuel economy. I saw online or on TV, don't remember now which, but rolling the windows down decreases economy ever so slightly more than using an air conditioner. However, an air conditioner will cool you much more efficiently and is definitely the way to go if one had a choice.

Adding another alternator and/or battery won't help mileage. Yes, maybe less strain on electrical system if you have a ton of factory plus aftermarket electronics running, but for an air coditioner, no need. A higher capacity alternator, like a 100 amp or so, has a bigger magnet compared to a stock, 60 amp or so, alternator. The bigger the magnet, the more the crankshaft has to turn, causing more strain on the engine, thus decreasing mpg.

Most people add another alternator to help recharge their battery due to huge losses of power from high end stereos, etc. A normal air conditioner wouldn't qualify for needing another/bigger alternator.

Adding another battery is the same concept. This involves weight more than rotating engine accessories, though. The more a vehicle weighs and has to push down the road, the less mileage it'll get. Also, I know Optima makes a 6 volt battery. You could get two of those to fit where a single, regular 12 volt battery does, but you'd still have 12 volts. lol But it would be kinda' cool to have somethin' different...

If you have a hole bunch of aftermarket electronic stuff, then another alternator and/or battery would be a good idea, but the more you add, the worse off your mpg will be.

In a nut shell:

An air conditioner decreases mileage to give you refrigerated, de-humidified air.

Rolling the windows down decreases mileage slightly more than an air condtioner does, but only gives you air movement. That air could be hot, humid, or both, etc.

If you want cool...Sacrifice a little mileage and get your A/C blowin'.

Post by **occasional demons** » Thu Aug 27, 2009 11:49 pm

I get better mileage with the windows down, almost no difference than with them up. The A/C will make a huge dent. On some cars, the A/C may be more efficient, but the neon isn't one of them.

Speed also plays a factor. The A/C would prolly be more efficient at 70 mph, but not at 35 mph.

Moparty08 · Post by **Moparty08** » Fri Aug 28, 2009 12:36 am

Ok i definitely am just gonna deal with it. I didn't go for anything but a udp and an odp.
I haven't had ac in a car for like 8 years so it's nice to finally have some.
at first it was on ALL the time. Now i've done better. I put it on only when i'm on the highway and i'm still averaging about 30 mpg so it's not bad at all. Thanks for the help guys.

Just got one more question. On my 04 it seems the hvac just blows harder than my 01. Could it be my blower motor on my 01 is just getting old? i'm not gonna change anything right now but would this help?

PhillyLS1 · Post by **PhillyLS1** » Fri Aug 28, 2009 7:42 am

This thread is facepalm.

ITSANSS · Post by **ITSANSS** » Fri Aug 28, 2009 8:02 am

PhillyLS1 wrote:This thread is facepalm.

You have no future

Post by **racer12306** » Fri Aug 28, 2009 8:11 am

I wonder why I get 35-40mpg with the a/c cranked

Post by **occasional demons** » Fri Aug 28, 2009 11:16 am

racer12306 wrote:I wonder why I get 35-40mpg with the a/c cranked

Is it because you were driving the prius?

Seriously, tho like I said at highway speeds, I can buy the windows down argument, but at 35 to 45 mph, no.

Even with the UDP, my A/C compressor drags down the acceleration with urban driving. When going down the highway, it is much less noticable, due to not changing speeds.

Post by **racer12306** » Fri Aug 28, 2009 11:18 am

nah, its in the Neon.

The Prius with the A/C cranked get a minimum of 47mpg. On a long trip, 55mpg

Hudson_Neon · Post by **Hudson_Neon** » Sat Aug 29, 2009 8:04 pm

Dylan-00Blue wrote:.......a/c pwns milage it will get shitted on so hard leave the a/c off and use the flow through vents.......

this is NOT true. with modern a/c compressors and compressor clutch assemblies, the difference is minimal. MAYBE 1mpg. although it doesn't make a HUGE difference with our cars, windows down actually does worse than the a/c being on. the windows open actually causes more drag and sucks more power than the a/c compressor does. best bet is to just use the a/c if needed, otherwise just use regular air.

LilSparkPlug · Post by **LilSparkPlug** » Sat Aug 29, 2009 8:38 pm

28.7mpg to 32mpg on the highway....70mph with the AC on. That's a live reading from my scangauge.

With heavier accel of course it goes down, uphill it's around 23-24mpg live. The difference is 1-2mpg at MOST between on and off.

excon · Post by **excon** » Sun Aug 30, 2009 2:11 pm

It was on mythbusters.

You're better off putting the windows down at low speeds ~40 and under. It will have almost no effect on fuel economy.

When you're on the highway turn the a/c on. It's better than rolling the windows down because of drag (as others have said).

DUH.

LilSparkPlug · Post by **LilSparkPlug** » Sun Aug 30, 2009 3:15 pm

I just run the AC all the time....screw the windows when it's over 100 outside...that's like soup blowing in my face....yuck.