Hello from a newbie - Sonata defroster

Hi:

I just bought a 2004 Hyundai Sonata LX last week, and have been
extremely happy with the purchase. It's a great car!

Just one small problem though - the a/c has a habit of coming on
automatically whenever you change mode or have the defroster turned
on. Also every time you start the car the a/c comes on if the
defroster is on. I hate driving everywhere with the a/c on and as I
live in New York it really is only necessary over the summer months.
I also shudder to think of the effect on the gas mileage especially as
we have some of the most expensive gas in the country.

Has anyone found a way around this (apart from shutting the whole
thing off and riding around with the windows open!!)?
Peter

 

The a/c comes on automatically when the defroster is turned on in this
vehicle to aid in defrosting. The A/C acts as a dehumidifier. I believe
you can manually turn the A/C back off by pressing the a/c button, but
this will greatly decrease your defrosting capabilities.

 

The defroster is doing exactly what it is supposed to do. By default,
the AC compressor runs to dehumidfy the air, increasing the defogging
speed it provides for your windshield/side windows. This system has
been in place in MOST makes/models of cars for years now. Where have
you been?

This also provides the added benefit of using the compressor during
the non-cooling season, allowing the oil in it to circulate. This
benefits the entire system.

Don't worry about the effect on your gas consumption. Many years ago
running the AC seriously cut into your mileage, but anymore it puts
very little drag on your engine, resulting in only a very slight
amount of extra fuel consumption.

So just relax!

 

I can confirm this with my Auto 04 Elantra GT. After a 500 mile round-trip
over 3 days with a mixture of speeds and road types that normally averages
31mpg without the AC on, dropped to around 29mpg with the AC on for about
250 of those miles.

Neil.

 

I can confirm the exact opposite. After a 2800 mile round trip in
four days, I got about 35mpg/gallon with and without my AC running.
The difference with the AC running was not noticeable. (This is a 2001
Elantra GLS).

This kind of evidence is not empirical and entirely anectdotal.
Studies have been done and the data is out there showing that modern
AC systems have neglible impact on gas consumption. I trust those
over what happens on a few cars that people give "their" stories
about.

 

::sigh:: I'll be sure to add the disclaimer, "your mileage may vary" in
future so as not to confuse people into thinking I was implying my
experience was anything other than my own experience.

If you're so adament that correct and factual evidence be quoted, how about
showing us some references, otherwise how am I to believe *you*?

Happy driving.

 

Do some research at a local library. I found the stuff I needed at a
local university library using one of their abstract systems that
searches current literature. Systems like that contain so much more
than the books ever can, as periodicals and peer-review stuff is so
much more topical and current.