Aseras

I live in vero and i've never had a problem with overheating except on a dyno... and that was just overflow from the coolant tank.

I regularly see 110+ when I get in my car everyday. humidiy is almost always 100% since I work on the ocean/river.

Winfree

I suspect the problem was heat, plus freeway stop and go, with dozens of other cars adding their contribution to the problem. There seems to be a reason for all that air space and scoop under the car.

Our midday temps are around 107 (this is dead on normal for this time of year, so we always hold the midstate fair at this time) and no problems with the car, and air conditioning so good that grandma complains of getting chilled when its on high. But we have no stop and go driving - it's clear all the way to the beach! (Beach temperatures 68 or less, and night time temperatures drop down to 73 inland with light fog).

Car washes are out ot the question, at least after 9 am, because spots will form before you can dry the water off... And playing in the hood not a good idea until late afternoon.

Car only uncomfortable if it has been sitting out in the sun at Walmart - that's why we have a fuzzy wheel covers, and are trying to work out modifications for seats so we can use sheepskin covers. Want to keep the leather nice, and sheepskins are cool in summer and warm in winter.

And Arizonia - I definately understand Slurpies and frozen drinks - they are the secret to desert comfort and survival!

NoTears316

I seriously doubt humidity is playing a large part in vehicle performance. To a car, heat is heat. Like it was already explained, humidity doesnt actually increase the temperature it makes it "feel" hotter to people due to, well... I'm not gonna retype it, just read Paul's post.

licid222

I live in Memphis where it is very humid and the temp gauge has been reading 100+ most of this week. Only thing I've noticed is the fan that cools the engine runs for at least 10-15 minutes after the car has been turned off. A lot of the time it is still running on the car after I've gone into a store to pick something up. Anybody else have this happening in this weather?

Paul_in_DC

Heh. Hell I took physics, but I'm not an expert at thermodynamics.

Oddly enough I did find a discussion at a site on flying that verifies that humid air is less dense than dry air due to displacement of oxygen/nitrogen molecules with lighter water vapor molecules. (Which was not intuitive to me.) Now I'm curious whether there is a significant heat transfer differential between oxygen/nitrogen and water vapor molecules. Intuitively I suspect that heat transfer would be more efficient in humid versus dry air, but that may turn out to be wra... wroo... wrom... er, less than totally right.

I haven't stayed at a Holiday Inn Express lately. Maybe that's part of the problem.

r0tor

iTrader: (1)

ugg... someone look up the term "heat index". It combines the real temperature with the relative humidity and comes up with a temperature that it feels like it is if there was no humidity.... so 90 degrees F and 60% humidity makes it feel like its 105 degrees (or something like that). It accounts for the added heat energy in the air combined with the decreased ability for sweat to evaporate off your skin to cool your body.


the real problem is he's on I95 in philly - which pretty much means you will travel 15 feet every 5 minutes during rush hour while being trapped in the baking sun surrounded by cars and having only the fan blowing air over the radiator (and nothing over the oil coolers) with the AC on

speeddemon32

this has nothing to do with an RX-8, but when we were driving back from Vegas on Sunday it was 127 in Baker California. (Vegas was VERY hot also)

BunnyGirl

A few weeks ago we had a 100-plus day. I parked in the garage at work and turned off the car. The fans turned on. I got out, locked it up, and started to walking away. Some guy walks buy to get to his car. He hears my car, looks at me, rolls his eyes and kind of shakes his head and tells me I forgot to turn my car off!!! I told him those were just the cooling fans and it was perfectly normal. He gave me an even weirder look told me I'd better check my car again to make sure it was off, and then walked off shaking his head like I was some kind of moron.

I don't know how long the fans were running since I went in to work and it was about two hours before I went to go check on Bella on my break. By then it was off.

Huey52

iTrader: (2)

The descending order of air-flight goodness is:

Cold Dry
Cold Humid
Hot Dry
Hot Humid

If you've ever tried to lift a near max weight helo off in Hot-Humid weather you very rapidly gain an appreciation for relative air density. Of course this is a wing-lift thing and not a heat-transfer.

But I digress .....

As NoTears316 cites, it's not a huge difference from Hot Dry to Hot Humid in our automotive cooling discussion. Hot is hot.

Far nicer today. Almost 20 DegF cooler.

saturn

Agreed, but we sorta started talking about AC units in which humidity is going to make a difference. I don't give two craps if my car is hot -- I care if I'm hot when I'm in my car. My car is my bitch.

zoom44

yes exactly- which is why we are seeing more heat related engine failures in the dry southwest than elsewhere- the humidity makes for better cooling of the oil thru the coolers. it doesnt get that aid in the dry areas

XRX8X

to:bunnygirl!..next time tell him to stick his face up the tailpipe and feel the exhaust coming out

rx8-rus

I also noticed that cooling fan runs much shorter after I turn off the car than before. It turns off in less than a minute, unlike last summer when it could run for several minutes. I still suspect new software: could it be that developers decided increase temperature threshold for fan trying to save battery charge (and reduce a chance of flooding)? They could just forget to keep the old threshold when engine is running.

Easy_E1

iTrader: (2)

My cooling fan will run for about 10 minutes when I pull into the garage.
I thought that dry air compared to humid air made it harder for a plane to take off?
They say that at PHX. SkyHarbor Airport.
When it is hot the planes have a hard time taking off.
Due to a lack of density on the moleculer level.

Johnnyma45

I second this! Not only do we have schitty winters with 8 ft drifts, but we have 95 deg humid days like the past weekend. Anyways I posted in the tech garage too, but today my car actually stalled at a light because the A/C was on. I had it on the 2 setting, and the car had been struggling to get any kind of power at any RPM the entire way home, and finally gave up when rolling in neutral up to an intersection. I was able to start it back up, but this can't be normal.

jaguargod

Yesterday in the Dallas, Texas area my temp. read 118 degrees. We aren't used to those high temps like you guys are in AZ, so it makes a big difference. By the way, I did the throttle body bypass mod this year, and my car has handled the heat just fine. It was cooler last year, and I had really bad performance in the heat. One of the best and cheapest mods I have done to this point.

Paul_in_DC

Not so, as Huey52 explained, and I read at another site. However, in hot air it's harder to take off than in cold air. I noticed that one day watching planes come into National Airport, and they we moving like a bat outa hell. My buddy who was with me (who is an ex air-crew) explained the hot/cold air density thing, and that in hot air they have to move faster to get the same lift.

Meanwhile I'm still trying to get more info on the dry/humid heat transfer thing. Stay tuned...

yocoop

mine died twice.....they replaced spark plugs and gave me the newest powertrain flash..its working..I also was on i-95 in philly on the way to the dealership only mine totally stalled out.

swoope

iTrader: (5)

so my observation was right????

hummmmm, do i get a cookie???

beers

swoope

iTrader: (5)

accept the fact that you know more about cars than most guys....

next time you hear a comment like that look at them like the moron they are..

or you look at them and say duh!!!!

beers

DOMINION

No. You get