Mythbusters on auto Air-conditioning

what makes you happier? I can drive longer with the AC on. Not only from a comfort level, but from an entertainment level. If you want to hear your CD or public radio, windows up. Since time is money, I'm for AC.
 
pgwenthold said:
The small difference between windows and AC isn't the problem when you are going fast, where the efficiency is lower. And it doesn't cost you much in time, just a couple of minutes usually, and, moreover, I don't care if I see a cop, because he isn't going to bother with me at 58 mph. In terms of benefit, given two tanks of gas each week, and gas prices of 2 - $2.50, I figure I can save about $4 - $5 a week in gas, or $200 - $250 a year. Just by slowing down.
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At 4 minutes each way you are wasting 8 minutes/day or 40 minutes/week or 2000 minutes a year. That is over 33 hours. Your $200 savings divided by your 33 hours spent earned you a whopping $6/hour.

Is it possible that people that drive BELOW the speed limit put themselves and others at risk? In NYC if you are doing 70 in a 55 you may be the slowest person on the road. Even in Iowa driving below the speed limit encourages others to pass when they otherwise wouldn't have to causing unnecessary risk - all for $6/hour.

Full disclaimer: I do not drive.
 
Any idea if the Mythbuster tests would have similar results in a sports car at 80MPH? What about a cab doing 60 on the FDR, or in sit 'n sprint traffic?
 
Gulliamo said:
At 4 minutes each way you are wasting 8 minutes/day or 40 minutes/week or 2000 minutes a year. That is over 33 hours. Your $200 savings divided by your 33 hours spent earned you a whopping $6/hour.

Is it possible that people that drive BELOW the speed limit put themselves and others at risk? In NYC if you are doing 70 in a 55 you may be the slowest person on the road. Even in Iowa driving below the speed limit encourages others to pass when they otherwise wouldn't have to causing unnecessary risk - all for $6/hour.

Full disclaimer: I do not drive.
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For me your analysis is a little faulty. For most of my life I generally drove in the fast lane at around 80 mph. At that speed there is always a little tension around the possibility of a ticket. And as has been noted fuel economy is decreased. Also there may be a little more tension with the drive particularly when driving next to the cement barriers that separate the two directions of freeway traffic. Those all seemed like reasonable tradeoffs when I was working 50 plus hours a week and I was either striving to get to work on time or I was trying to get home as fast as possible because I was tired.

Now, I work a few times a week for roughly five or six hours a day renovating an old apartment building. If I take a little longer getting there or getting home I'm ok with it. I might listen to talk radio, maybe eat a little lunch and pretty soon I'm where I was going. I'm not scanning my rearview mirror looking for cops because I know I'm going slower than a speed that they would ticket, in general I have a nice little peaceful road trip and I save a few pennies on gas. Sometimes that can even be part of the diversion as I try to set a new record for how many miles I get on a tank of gas.
 
davefoc said:
For me your analysis is a little faulty. For most of my life I generally drove in the fast lane at around 80 mph. At that speed there is always a little tension around the possibility of a ticket. And as has been noted fuel economy is decreased. Also there may be a little more tension with the drive particularly when driving next to the cement barriers that separate the two directions of freeway traffic. Those all seemed like reasonable tradeoffs when I was working 50 plus hours a week and I was either striving to get to work on time or I was trying to get home as fast as possible because I was tired.

Now, I work a few times a week for roughly five or six hours a day renovating an old apartment building. If I take a little longer getting there or getting home I'm ok with it. I might listen to talk radio, maybe eat a little lunch and pretty soon I'm where I was going. I'm not scanning my rearview mirror looking for cops because I know I'm going slower than a speed that they would ticket, in general I have a nice little peaceful road trip and I save a few pennies on gas. Sometimes that can even be part of the diversion as I try to set a new record for how many miles I get on a tank of gas.
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I can see your point, if you have nowhere to go and all day to get there then a time=money analysis is useless. If, however, you are driving below the speed of traffic to simply save money then cost/benefit analysis may do you some good.
 
There was a Sprint Turbo as well. 70 horses, I believe.

We had several cars many years ago that got very high mileage. Geo Metro, Chevy Sprint, Honda Civic HF.

None of them were hybrids, either. We are just now getting back to those numbers, but only with hybrids.
 
The Sprint I had was actually plenty peppy. It had a three cylinder 1L engine, and was very lightweight. A/C would probably have killed some of it's economy advantage. But it was quick and held it's own on the highway. It was a rather simple machine, ALWAYS got me to my destination. The couple times it didn't start was due to a dead battery. The car, however, was so light and small, it wasn't much of a task for me to bump start it myself. It was even a four-door and realistically carried four people comfortably. It lasted fifteen years, several trips across country, and almost 200k mi. If it didn't need a brake job at the same time as a new clutch, I probably would still be driving it today.

I'm sure the current hybrids are nice. They should be for the price. It just kinda makes me chuckle a bit inside when I see the estimated MPG numbers, knowing that they're only slightly better than the cheapest economy car of 1986.
 
I would love the mythbusters to see if you can actually shoot at a lock and chain with a gun and break them. Particularly a chain. I always shudder when they do that in a movie. I expect the bullets would bounce off and hit you if you were standing close.
 
I guess it depends on your body chemistry. I myself much prefer having the window open in the car to using the air conditioner. I just think you are most often just trading being a little hot to being a lot cold. I would much rather be hot than cold. I usually don't even run the air in my house in the summer time. I have a fan blowing on me all the time and I am fine, regardless of the temperature and humidity.
 
Gulliamo said:
I can see your point, if you have nowhere to go and all day to get there then a time=money analysis is useless. If, however, you are driving below the speed of traffic to simply save money then cost/benefit analysis may do you some good.
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Nominally, yes. That 8 minutes a day difference could be time better spent. Or it could be time spent reading JREF, in which $6/hour is clearly worth it. Or it would be 8 minutes a day at home watching TV.
 
kevin said:
Also I thought the worry about the tires blowing out was weird. I've done 12 hour drives in cars at 70-80 mph without problems, with only stops for the restroom and lunch.
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Didn't they do this on an high-speed bowl. I.e. with banked corners?
These allow you to drive with the same steady speed through the corners (or it's just one big corner), but this generates a lot of heat in the tires.

davefoc said:
The only things I do are to keep my tires inflated and to drive with as little braking as possible meaning that I try to be aware of slowing traffic and allow the car to slow itself down before I need to use the brakes.
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Overall, this is the best way to drive. It keeps you aware of other road users, hazards etc, instead of dozing of. Good work.

LTC8K6 said:
There was a Sprint Turbo as well. 70 horses, I believe.

We had several cars many years ago that got very high mileage. Geo Metro, Chevy Sprint, Honda Civic HF.

None of them were hybrids, either. We are just now getting back to those numbers, but only with hybrids.
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Cars of the late seventies, early eighties ran very lean mixtures, thereby giving them great economy. This also meant they spewed out great amounts of NOx. With catalystic convertors, Lambda got back to 1 (air:fuel ratio of 14.7:1), this increased the fuel consumption.
 
As far as I know, the Sprint, Metro, and Civic HF were late 80's and early
90's models with catalysts.

The Civic HF was also a flex fuel vehicle.

I think it was the earlier CVCC that did not use a catalytic converter.
 
Shrike said:
... Cars of the late seventies, early eighties ran very lean mixtures, thereby giving them great economy. This also meant they spewed out great amounts of NOx. With catalystic convertors, Lambda got back to 1 (air:fuel ratio of 14.7:1), this increased the fuel consumption.
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Just goes to show --- you can't get something for nothing; or perhaps whatever you want must be paid for with something else. One of my favorites was (is?) with oxygenated gasoline -- basically it yielded 10% less pollution, but gave you 10% less mileage. Go figure.

And why are owners of bigger vehicles (SUV's and Trucks) allowed to pollute more? The pollution levels are grams per volume of emitted gases, not grams per mile, right? There is no way you can tell me that an SUV getting 8 mpg is polluting the same amount of grams per mile of NOX and CO as the same model year Civic.
 
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LTC8K6 said:
As far as I know, the Sprint, Metro, and Civic HF were late 80's and early
90's models with catalysts.

The Civic HF was also a flex fuel vehicle.

I think it was the earlier CVCC that did not use a catalytic converter.
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I think the DVCC's were somewhat later in getting catalysts but they had a catalyst by 84 or 85. My 85 Civic DX had one. One of the last cars to have a carburetor, an incredibly complex system using literally dozens of vacuum lines, running to a couple of large black boxes filled with relays, solenoids, valves and the like, but without electronic control. It was like a huge pneumatic computer. I averaged about 42 mpg without trying very hard.
 
Shrike said:
Cars of the late seventies, early eighties ran very lean mixtures, thereby giving them great economy. This also meant they spewed out great amounts of NOx. With catalystic convertors, Lambda got back to 1 (air:fuel ratio of 14.7:1), this increased the fuel consumption.
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My old Sprint did have a catalytic converter. In addition it was purchased and spent most of it's life in California, which seems to have rather stringent emissions controls on automobiles. It did stop voluntarily passing state smog checks around '93 or '94, a problem which was remedied with some relatively simple hacks. While the car's emissions got worse over with age, it's also possible that the state's emission standards got tighter over the same period.
 
shecky said:
While the car's emissions got worse over with age, it's also possible that the state's emission standards got tighter over the same period.
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That's odd ... can a state require a car over time to somehow improve its emissions? I mean, shouldn't the levels of emissions for that model year be held constant, as who can expect it to somehow meet later standards?
 
Vagabond said:
I would love the mythbusters to see if you can actually shoot at a lock and chain with a gun and break them. Particularly a chain. I always shudder when they do that in a movie. I expect the bullets would bounce off and hit you if you were standing close.
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I don't watch much TV, and don't remember now where I saw this, but they or someone like them did just this, shooting at padlocks. The locks won.
 
Just thinking said:
Just goes to show --- you can't get something for nothing; or perhaps whatever you want must be paid for with something else. One of my favorites was (is?) with oxygenated gasoline -- basically it yielded 10% less pollution, but gave you 10% less mileage. Go figure.

And why are owners of bigger vehicles (SUV's and Trucks) allowed to pollute more? The pollution levels are grams per volume of emitted gases, not grams per mile, right? There is no way you can tell me that an SUV getting 8 mpg is polluting the same amount of grams per mile of NOX and CO as the same model year Civic.
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Hmm. I don't have any data on me, so feel free to disregard this, but I read an article a year or two ago that indicated that while trucks and SUVs are allowed to pollute more than cars, they generally are only lagging cars by a few years in emisions. That is a 2000 model SUV would be similar to, say, a 1995 car. SUVs of today are much cleaner, emissions-wise, than even the most economical cars of the 70s
 
This is why I like living in the UK. You don't need AC or to open the windows.
 
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