Using non-ac serpentine belt improve mileage?

[v6underpressure]

I live in the Chicago area, so I dont use the AC for probably 9 months out of the year. I wondered if I could just purchase the Non-AC belt to swap on during these 9 months to eliminate drag from the ac compressor. Would it be worth it to pick up another belt and do this? Thanks in advance!

 

[alaskan155]

a/c has no drag, just unplug compresser 2-wire plug and viola the clutch wont engage, even when defrost is on

 

[Gotta_gofast]

there is a reason your ac compresser cycles you know...

 

[Ozwynn]

the defroster works better with the A/C...... the A/C dries the cab. your Defroster works around 50% quicker with a functioning A/C

 

[v6underpressure]

I had no a/c on my old regal before, and I never had any issues defrosting at all, and it defrosted just as quickly as with A/C. Any extra pulley, (clutch engaged or not), causes drag.(you still have to turn the weight of the pulley) If no one has done this, then has anyone noticed any increase in mileage with your compressor simply unplugged?

 

[scotts90ranger]

I think that AC on while defrosting thing was disproved a while ago, but I bet it's more to keep the system cycling and working in the off season...

but like everyone else said, with the clutch disengaged it doesn't really take any power away, the only thing that would give it less gas mileage over a non AC truck would be the added weight of the components

 

[gw33gp]

Anyone that disproved AC with defrosting was using bad testing. The AC removes a lot of moisture out of the air and helps defog much faster. To defrost it also requires heat but the dry air from the AC still helps with that.

I had the AC compressor freeze up on my 99 Cougar (2.5L V-6) on a long trip one time. I decided instead of paying an exorbitant amount to get the compressor replaced by someone that was not specialized on it, I would just have a non AC serpentine belt installed. I thought too there would be no difference in power or gas mileage compare to running with the AC off. However, I could tell right away that car had better acceleration with AC by-passed. I also got better gas mileage than I ever got with it before. The best I ever got before when running around 70 was 28 mpg. I was getting over 30 mpg with the AC bypassed. I was driving through Southwest USA on I-10 in August and it was very uncomfortable. I probably paid more for drinking water than I saved in gas so it was not worth it but it is possible to get better mpg by using a non AC serpentine belt to bypass the AC. I don't know if you would see much improvement with city driving but I would expect some improvement.

You can give me all the theories you want about a non-engaged AC has no drag because I use to believe it too. My experience tells me something else.

 

[Vince near Seattle]

I agree with gw33gp. The A/C compressor in my 1994 2.3L manual Splash died so I installed a non-A/C serpentine belt and gained 1 to 2 mpg depending on the type of driving I was doing (city/highway). I live in the Pacific NW so we only need A/C a couple of weeks a year, I'm thinking about removing the A/C entirely...

 

[AllanD]

You are not going to gain 1-2mpg foy bypassing what is in essence
an idler pulley when the clutch isn't energized.

If you noticed a difference it was entirely by placebo effect.

Frankly I don't see a 1-2mpg difference in driving with the A/C On or Off

The difference is more like 0.75mpg.

AD

 

[v6underpressure]

Anyone that disproved AC with defrosting was using bad testing. The AC removes a lot of moisture out of the air and helps defog much faster. To defrost it also requires heat but the dry air from the AC still helps with that.

I had the AC compressor freeze up on my 99 Cougar (2.5L V-6) on a long trip one time. I decided instead of paying an exorbitant amount to get the compressor replaced by someone that was not specialized on it, I would just have a non AC serpentine belt installed. I thought too there would be no difference in power or gas mileage compare to running with the AC off. However, I could tell right away that car had better acceleration with AC by-passed. I also got better gas mileage than I ever got with it before. The best I ever got before when running around 70 was 28 mpg. I was getting over 30 mpg with the AC bypassed. I was driving through Southwest USA on I-10 in August and it was very uncomfortable. I probably paid more for drinking water than I saved in gas so it was not worth it but it is possible to get better mpg by using a non AC serpentine belt to bypass the AC. I don't know if you would see much improvement with city driving but I would expect some improvement.

You can give me all the theories you want about a non-engaged AC has no drag because I use to believe it too. My experience tells me something else.

Good info gw33p. I think I am going to try this. As far as the defrost using the AC, I never noticed a difference, and I have tried this in numerous vehicles. Hot air evaporates water therefore defrosting and drying the window. I do agree that it may help, but VERY little. I don't see a use for it in my 15 years of experience. Some cars you can purchase without AC. What do they have, a mini AC system??? Nope, it works fine without.

 

[James86]

You are not going to gain 1-2mpg foy bypassing what is in essence
an idler pulley when the clutch isn't energized.

If you noticed a difference it was entirely by placebo effect.

Frankly I don't see a 1-2mpg difference in driving with the A/C On or Off

The difference is more like 0.75mpg.

AD

I'm gonna be honest, I think this is sorta like the whole ripping out a mechanical fan thing.... if the clutch (in either case) is going bad - both of you had your AC fail and THEN bypassed it - then of COURSE you'll notice a difference. But what if you'd just gotten a new compresser with properly working clutch?

 

[06RangerXLT]

I'm gonna be honest, I think this is sorta like the whole ripping out a mechanical fan thing.... if the clutch (in either case) is going bad - both of you had your AC fail and THEN bypassed it - then of COURSE you'll notice a difference. But what if you'd just gotten a new compresser with properly working clutch?

yes, spinning a fan is just like spinning a bearing. thats why they use 5-15hp motors to run gas powered fans...thats also why we have hand crank leaf blowers...

now wheres that....


ah..




bypassing it will only help if you run ac. but if you think its gonna do something, try it. i decided to stop listening to everyones opinion on what they "think" would work, and figured out actual things myself. ive realized most people have little to no mechanical experience, and are talking because of what they have heard. most false facts are the exact same. mechanical fan uses less power then an electrical one. (i otta smack ya) a tonneau cover wont help wind drag *smack*, old tires use more fuel, ect ect.

 

[85_Ranger4x4]

a/c has no drag, just unplug compresser 2-wire plug and viola the clutch wont engage, even when defrost is on

Playing with a tuner set to display "engine load" on my F-150 the engine load went up about 5% with the AC running at idle. While moving there was no difference.

 

[James86]

06RangerXLT, I think you took my comment out of context. Two people who have cited improvements BOTH had their compressers die, so wouldn't it seem reasonable to say that just before they died, the compressers may have been on the way out bearing wise anyways? Maybe I'm misteaken, but I thought the guys with "Tech Adviser" tags might know what they're talking about, and I agree with him. If the clutch is NOT engaged, then why would there be much of a difference? I merely cited the mechanical fan raguement because it's been said before that someone probably noticed a difference partly because their fan clutch went out and was locking up more. Note I said "partly." As for the engine load, 85_Ranger4x4 says that at IDLE he noticed his load go up 5%. thats at IDLE, below the power band, and below the rpm an engine normally spins at. While MOVING he noticed no difference. My experience has been similar - if I do a lot of stop and go in town driving with the AC on, sure, I'll notice that extra drag from a stop and what not, but on the interstate doing 70+ I'm in my power band. and don't notice my AC at all.

Maybe it seems like I don't know what I'm talking about, but I read all of the posts, and I know what my truck is like after owning it over half a decade. What my truck is like is not necessarily like all trucks, but the question was asked and I gave my two cents. No reason to dig up an emoticon because you disagree.