High Air Temps 110-111 F – Traction – Differential
 

Hi everybody,

I guess that your are used to strange questions so here is mine:

What is the relation of street temperature and traction? I have this question because lately in my country Greece we have the following conditions:

1) Low traction Tarmac
2) A lot of dust on Tarmac
3) high air temps 110- 111 F

The 1) and 2) is a common condition. However lately that we also have factor 3) the very high temps I have noticed that when we have high temps my RX-8 seems to be sleeping more on the street special on low speeds. It seems that in these conditions the car’s traction is somehow impaired.

So my question is: Ηigh temp is the factor that providing these low traction conditions OR is the car that is very hot so hot that the differential is not working as it should so in low speeds it locks more often when is hot thus giving me low traction and sleeping tail ????

Thanks


I guess that my query is very strange and it is difficult to be answered however this is a situation which is real and happening.

if the roads/tarmacs you have are low traction and the temps. are high, heating your tires probably occurs faster then normal, and if forza 2 is right, and it is, hot tires are garbage for traction.

Living in Arizona, we see these kinds of temperatures which are common in the desert climate. While most of the roads are not tarmac, much of the same effect can be experienced.

Your traction abilities with your tires will mostly come down to the type of tire you run. While a softer tire will cleary give you better traction, the heat will cause the rubber to wear faster in some respects as opposed to a harder tire. In either circumstance as the air temperature rises, you can expect your suface temperatures to be much higher.

110-115 degrees here in Phoenix with clear sky conditions you can expect surface temperatures to be at or above 140 degrees. I know Mazda Maniac has gathered some actual numbers so maybe he will post them up.

I can't speak for how the temperature effects the diff but clearly your traction will be impaired due to high heat. Even more to the point, with temperatures above 110 degrees you seriously risk overheating the car with any spirited driving and high RPM driving. The stock cooling system is ill-equiped to handle anything beyond normal highway driving with these excessive temperatures.

It really depends on the tire you have. Some tires like a little heat in them to generate maximum grip, but other tires grip best in cooler conditions and if the ambient is 110, then like it's been mentioned the surface temperature probably closer to 140 and that might be warmer than some tire's optimum operating temperature.

Try 165°F or higher. My highest was a section of I-10 just south of Ray - 172°F.
This was with a 109°F ambient.
Conditions in Greece are a bit different - its not desert - but you can certainly expect the road to reach temps 30°F or more over ambient.

Some tires become "greasy" after 140°F or so. The nominal operating temp for most street tires is below 120°F.
BTW - 126°F is the "calibration" point for my hand. At that point, hot stuff hurts. So, now I can check my tires with my hands...

Wow, I didn't realize the temperatures went up THAT high!

Still, clearly with even 30 degrees above ambient temperatures you are still going to be overheating the tires to the point where the rubber starts flying off under performance conditions.

Thanks for the stats MM.

Ι think that you are right guys. My tires were VERY hot when I touched them.

So to understand, if the tires become TOO hot their traction ability is impaired.

Do you propose to use higher pressure in my tires in order to somehow decrease their temperature in these conditions?


Also what do you think about THESE hi temps and differential? Can the diff be affected from these kind of temps?

Very useful information. I think that my problem is that my tires due to hi street temp become very hot and as a consequence overinflated.

http://www.turnfast.com/tech_handlin...pressure.shtml

Yesterday I noticed something different. Well, the ambient temp was at about 82.4 F and after some quick laps my tires became sticky. However, this sticky performance did not last long enough. Before I reach my destination I think that they become overheated and the “grease” effect appeared.

I wonder if a used tire with not much tread (like mine) can become easily overheated ?