A/C-gas ...worth it?
- Thread starter Alex91Mk3
- Start date
i just got a r-134 conversion done to my ac bout 2 weeks ago...its worth the nice cool air here in f-ing texas, but everytime i see the gas gauge go down in like 3 days i wanna off myself:cry:
If I had AC, I'd use it. Alot... those of you without AC saying you wouldnt use it much even if you had it, stop lying. you're not fooling anyone. 
yea mythbusters showed that in theory you get better gas millege with ac on and windows up... but in the real world it is in fact better for the other way around
Adjuster
Supramania Contributor
Oh, well if the scientists at mythbusters say it's true, then I'm changing my mind... LOL NOT!
Sorry, but here where we can go 75mph posted, and 82mph with never a second glance, running with the windows open and the AC off would be just stupid. The wind buffet is annoying, and I don't belive the difference in fuel use would be that much, or worth dealing with 100+ heat we've been seeing the past few weeks.
AC rules, and I don't really care what it does to fuel economy.
Sorry, but here where we can go 75mph posted, and 82mph with never a second glance, running with the windows open and the AC off would be just stupid. The wind buffet is annoying, and I don't belive the difference in fuel use would be that much, or worth dealing with 100+ heat we've been seeing the past few weeks.
AC rules, and I don't really care what it does to fuel economy.
on the show they took two suvs and had the cars both get up to speed at the same time using cruise control having one with ac on and the other with windows down and let them run till they ran out of fuel... the one with AC ran out of gas first and took the other car a lot longer to run out... They then switched drivers just in case that would be the cause and same effect happened...
there were some flaws im sure but to me it sounds pretty good plan...
there were some flaws im sure but to me it sounds pretty good plan...
aggie08281 said:
I was being stupid and was really tired last night...
Nissan Skyline GTR-R34............ R-134......bleh?
See the comparrison? I'm so stupid sometimes. :icon_razz lol...:icon_bigg
Adjuster
Supramania Contributor
Few things to consider about that "test".
1) They used SUV's. They are large bricks anyway, so generally there is tons of areodynamic drag to deal with on a SUV with or without the windows up or down. (It does increase as the windows go down, and the speed goes up, but they are square edged bricks with huge frontal areas to start with.)
2) They use large V8 engines that burn more fuel per revolution than our somewhat smaller 3.0 I6. All things being equal, at some point large displacement engines start to return a very similar fuel economy. Case in point. Chevy truck with a 454 gas engine. Get's 12 mpg on a good day, no head wind and empty. Load it up with camping gear, tow a few ATV's on a trailer and run it up into 20mph headwind? Guess what? Get's about 12mpg...
The amount of power needed by the vehicle to maintain speed is less than the amount of power being produced by the engine by a larger margin, so empty or fully loaded, that vehicle just gives you 12mpg either way. (And I'm guessing so did the SUV's used on Mythbusters.)
Ok, back on point. The only way to do this test would be to use the same vehicle on the same day driven on the same road under the same conditions. You don't have to run them out of gas. You just need a fuel container that has a clear sight tube.
Start with exactly the same amount of fuel. (Easy to do since you can see the fuel level in the sight tube.)
Drive the car down the road the same distance, then turn around and drive back. Measure the fuel level.
Fill it back up to the starting point, and repeat the test.
That would have been accurate.
Running two Stupid User Vehicles and changing drivers is not accurate. The engine's tune, state of fuel injectors, 02 sensor and so many other variables can affect the mileage quite a bit. Just going from one engine to the other would affect gas mileage. Were both SUV's the same mileage? If one engine was built better than the other, or had more or less wear than the other it will affect fuel mileage, possibly more than using the AC or not.
AC compressor pumps use quite a small amount of power. A few HP at most. At highway speeds, your vehicle needs a few HP to overcome the resistance of the air, and the grade of the road. (And all the other factors that add up like tire rolling resistance etc.)
I'm sure some math wiz could figure it out and give us the figures, but I still think basing your idea that AC sucks more gas than open windows is pretty dang silly. (Besides the fact that those of us with working AC are cooly driving around while your sweating and stinking up your car... )
1) They used SUV's. They are large bricks anyway, so generally there is tons of areodynamic drag to deal with on a SUV with or without the windows up or down. (It does increase as the windows go down, and the speed goes up, but they are square edged bricks with huge frontal areas to start with.)
2) They use large V8 engines that burn more fuel per revolution than our somewhat smaller 3.0 I6. All things being equal, at some point large displacement engines start to return a very similar fuel economy. Case in point. Chevy truck with a 454 gas engine. Get's 12 mpg on a good day, no head wind and empty. Load it up with camping gear, tow a few ATV's on a trailer and run it up into 20mph headwind? Guess what? Get's about 12mpg...
The amount of power needed by the vehicle to maintain speed is less than the amount of power being produced by the engine by a larger margin, so empty or fully loaded, that vehicle just gives you 12mpg either way. (And I'm guessing so did the SUV's used on Mythbusters.)
Ok, back on point. The only way to do this test would be to use the same vehicle on the same day driven on the same road under the same conditions. You don't have to run them out of gas. You just need a fuel container that has a clear sight tube.
Start with exactly the same amount of fuel. (Easy to do since you can see the fuel level in the sight tube.)
Drive the car down the road the same distance, then turn around and drive back. Measure the fuel level.
Fill it back up to the starting point, and repeat the test.
That would have been accurate.
Running two Stupid User Vehicles and changing drivers is not accurate. The engine's tune, state of fuel injectors, 02 sensor and so many other variables can affect the mileage quite a bit. Just going from one engine to the other would affect gas mileage. Were both SUV's the same mileage? If one engine was built better than the other, or had more or less wear than the other it will affect fuel mileage, possibly more than using the AC or not.
AC compressor pumps use quite a small amount of power. A few HP at most. At highway speeds, your vehicle needs a few HP to overcome the resistance of the air, and the grade of the road. (And all the other factors that add up like tire rolling resistance etc.)
I'm sure some math wiz could figure it out and give us the figures, but I still think basing your idea that AC sucks more gas than open windows is pretty dang silly. (Besides the fact that those of us with working AC are cooly driving around while your sweating and stinking up your car... )
Instead of switching drivers, wouldn't the test have been more valid if they switched the car using A/C and the one using windows for the second test. That way if one was more mechanically sound than the other the same car would have won both tests and the tests would be flawed.
they were brand new trucks off the lot and i dont know if they switched cars using the ac and using the windows.. but they drained the tanks first and then added a set amount to each... they both were driving at the same time one was just farther back than the other or something like that so weather conditions were the same...
btw im just trying to remember everything from the show im just restating what they said...
btw im just trying to remember everything from the show im just restating what they said...
Fuzz420
Are U Here 2 take My Baby
So With less words, some of yall disagree with the way MB setup and initiated the test.Yall should write up a detailed email critzing it and yall could a have good chance of having them redo the test. Ive seen them do this before because of viewer complaints on how the test was setup and initiated