Data on effects of weather

[bwilson4web]

On a round trip from Huntsville AL to Columbia SC at 65 mph, the mileage changed proportional to the air density. The air temperature ranged from 15F to 40F and back to 18F. No appreciable wind as it was under a cold, high pressure system.

Bob Wilson

[Diesel_Dave]

Originally Posted by slowmover

(What follows is strident, but it is directed at the attitude among the FE conscious that A/C is somehow optional; not at the author of the quote)

You obviously don't live in a place where heat is a constant, nor have you dealt with heat prostration. Heat kill more North Americans than all other weather events combined. And, as todays vehicle are not designed for ventilation the way they once were, the lack of A/C makes them hotter than in decades past.

I submit that if you worked in a vehicle in the hotter parts of the U.S. that you'd find this premise foolish. Safety when behind the wheel has much to do with being alert. Being drowsy, groggy, hell, just plain sweaty isn't any form of being alert . . where one sweats through his clothing numerous times per day.

There are outdoor jobs advertised here where a requirement is that one is already employed in an outdoor position. The cull is only partly for those who find it uncomfortable.

The control for being cold is easy: add clothing. There is no such e-z control for high heat & humidity.

Let's also, for safety's sake, add in the ability of A/C to greatly reduce dust and other irritants, as well as greatly reduce sound levels. These both wear down any driver quickly. So . . . temps of 90+, high humidity and heavy unavoidable dust. This is no extreme state confined to one area or only a few occupations.

Let me also add that it assumes one will never be old, injured, ill or distracted. Any combination of those, and, in the heat, one will simply not drive (if one is at all smart). A/C is a lifesaver in a larger sense.

No, for A/C, it is better to investigate the operation of components and the system as dealer-spec is often "off". We have all heard of "tolerance stack" and in proper A/C operation, IMO, consider it a given that there is something in even a brand-new vehicle's HVAC system that warrants tuning. The best A/C is the one whose compressor operates for the shortest times; and the blower at the lowest energy draw. Knowing "how" to use it is just as important for longest term efficiency. (Think of this as improvements to rolling resistance, where use is likened to aero penalties; as shorthand). I touched on it in this thread.

HVAC use in a vehicle has to be factored for an enclosed vehicle on the highways, no differently than for cold weather warm-up.

For most of North America there are only a few months of the year where temps are "ideal" from this perspective of FE.

Thus my earlier question about "prediction": vehicle spec first, climate & terrain second, and driver use plus driver skill afterwards are the major determinants . . but is there a short-cut about temps? Vehicle logging seems to be the singular answer (given adequate warmup -- which I posit as being 30-miles, minimum, for any vehicle). Past that, past those, perhaps we can start to make more general statements on weather data.


.

May I submit that people who work outside in South Texas probably have a different perspective on the benefit of AC that some of us who live in other more moderate climates (and for good reason)

[dcb]

Originally Posted by slowmover

(What follows is strident, but it is directed at the attitude among the FE conscious that A/C is somehow optional; not at the author of the quote)...

I understand your position, and if AC was only installed on such work vehicles in such climates I would agree. It is still a nice to have, but could make folks more productive, and yes I have had hot gritty jobs. It just isn't safety equipment any more than not having a cell phone is safety equipment.

But AC is everywhere, there are folks with their windows up, all the time, mixing heat with their AC when it is absolutely beautiful outside. For the vast majority of its use that I have observed it is optional/comfort/luxury/pure waste mode.

It isn't personal. There is no shortage of forums where people feel entitled to do what they want whenever they want, so hopefully you can be tolerant of a venue that challenges folks to think things through and not internalize my comments about AC usage.

[gone-ot]

...however, there is a BIG difference between (1) the option to turn the A/C off when you want and (2) the NO-option of not even having A/C available...because someone ELSE said so.

...two sides of dis-similar coins?

[dcb]

Really doesn't have anything to do with this discussion. I don't know who is saying you can't have AC?!? Problem is comforts slowly drift into "needs" over time in the vernacular, and in reality there is a big difference between comforts and needs.

[slowmover]

Originally Posted by dcb

. . Problem is comfort slowly drifts into "needs" over time in the vernacular, and in reality there is a big difference between comforts and needs.

Then you have misunderstood the necessity of A/C. If it were optional then it wouldn't be considered near-manslaughter to leave children and old people in a parked car. Windows open or not. Urban sprawl and the urban heat island effect -- combined with smog/ozone -- make living in a wide swath of the US A/C-dependent as cars are the only way to get around. That isn't a question of comfort, in reality. (Read up on the effect of no A/C for the hospitalized or the elderly in New Orleans after Katrina. Or Chicago in 1995).

One may as well argue the need vs. comfort of a roof. Or a windshield.

The reason this discussion belongs to this thread, of weather data, is that over a large geographical region A/C use has to be figured in. How it is used is no different, in main, than worrying over the use of the heater in re FE, and to the point of the thread title.

.

[PaleMelanesian]

Originally Posted by Old Tele man

PaleMelanesian -- Q: what kind of LINEAR regression equation do you get through those data points?

...by my 'eyeball integration' it looks sorta like: MPG = 0.3(ºF)+50

Sorry for the late response. You're very close. MPG = 0.28(F) + 51.9. I guess that means I should expect 52 mpg if we ever get down to zero degrees.

It also means if we ever get 171F temperatures I should be getting 100 mpg.

[dcb]

Originally Posted by slowmover

Then you have misunderstood the necessity of A/C.

I'm not talking about the elderly, or hospitals not designed for some measure of natural cooling, or about locking kids/animals in an oven. I'm not talking about removing AC in life threatening situations either.

I am questioning how in 40 ish years (long after roofs were discovered) americans seem to have lost their ability to cope with heat. There are even larger swaths on the planet that don't even have electricity, I'm not buying it as a necessity in general. Should we issue AC stamps with our food stamps if it is a requirement for life as you would describe it? Right up there with food water and shelter apparently.

I'm not buying into it. Maybe folks should read up on heat acclimation? http://www.irunfar.com/2009/02/heat-acclimation.html I appreciate the comfort factor and social pressures to not sweat, but that isn't natural.

[PaleMelanesian]

Count me in the "AC is nice but not necessary" group. I live in Texas, too. I worked a summer on a roofing crew in College Station - black asphalt shingles are... hot. My car's AC has failed and I'm not spending the money to fix it.

Some people handle heat better than others. I'm one of those. Some handle cold better than others. I'm NOT one of those. I don't ask my family to go without AC. When we drive the other vehicle (both for capacity and comfort) the AC runs. When I'm commuting alone it's up to me and I choose not to.

There's also a big difference between a moving car with windows open and a parked car. I wouldn't want to be in a hot parked car and don't expect anyone else to either. With even a little airflow it's a different story.

[larrybuck]

Looks like a un-civil war going on here! As has been mentioned, different people react to temperatures differently. If you are raised in Mobile AL., you're probably not going to be comfortable in Jackson Hole WYO., or International Falls.

We all get to snicker at times... When I see an Arizona tourist racing to put their jacket on when its 65F here; thats kind of funny.

If someone dropped me off in Charlotte NC. tomorrow; I'd be the one laughed at.

What I think is the sin; is the demise of all the natural air we used to get in older cars.
It ought, for safety sake, to be a law that requires all vehicles to be made with manual vents, whether they are equipped w AC or not!

All pickups should come factory with rear window sliders!

How about headliner fans w proper safety cage around it; placed smack in the middle where 60's cars always had the dome light. If it was powerful enough, a full car load would at least be getting some air!

I did live in NC for 11 years, growing up around here first. It took me about a year to get used to the higher humidity; never enjoyed it; one of my reasons for returning here!

I drove for a living in NC., usually 200-300 miles a day, 5 days-week. In a company vehicle (Econoline vans), it would get so hot that I would run the AC on low, and also run both side windows down a few inches. Obviously, not the best for mpg., but for my health in what I considered to be EXTREME circumstances! I was just cool enough not to pit out, but maintained enough reality with the real temp. outside, so that when I got out; I'd be better attuned to that reality.

My last 2 years there I got to drive my own PU w slider glass; never used air, but a lot of towels.

Here now; when it finally stops raining and actually gets up to 85F+, I can any 4wheeler when I can for the motorcycle.
Again, all climates are different. When it is finally summer here, as long as I stay away from mountain areas, I can trust almost some 60ish dry days in a row.
When in NC., I couldn't ride as regular, because those afternoon thunderstorms came many times like clockwork!