[CZARCAR (OP)]

water spray on rolling tires result in?
cooler tires & longer life?
watered asphalt & longer life?
better gas mileage from decreased friction?
worse gas mileage from added weight?
climate alteration from humidity???

[Geezer]

crashing into lamposts due to hydroplaning?

[CZARCAR (OP)]

crashing into lamposts due to hydroplaning?

thanx, gotta consider the position & capacity of the spray mechanism?

[CliffordK]

I think I'd avoid it.
You would likely be carrying at least as much water as gasoline (see another topic about filling fuel tanks).
http://www.thenakedscientists.com/forum/index.php?topic=39340.msg356414;boardseen#new

In the Indy 500, they talk about getting the tires warm for better traction.  I think the same is true with drag racing when they like to spin the tires before starting.

Here in Oregon we have issues that we get plenty of rain in the winter, and a relatively dry summer.  The roads then can become very slick with the first rain in the fall, presumably due to oil and dirt being deposited on the road surface.  I don't know if that is only water on the road, or would also affect wet tires on dry asphalt.

[CZARCAR (OP)]

ok, add a IR temp sensor to calibrate temp of tires?

[Geezer]

I wonder if water actually decreases rolling resistance? You might need to do some experiments to find out. I do know that a lot of water really does increase drag - you can feel the effect on the steering when one side of the car goes through a large puddle.

I had a crazy idea about an inflatable band that is embedded in the "equator" of a tire. The idea would be that, when the car is cruising, the band is inflated so that it is pretty much the only thing in contact with the road - a bit like the skinny tire on a racing bike. When there is any braking or significant steering, the band immediately deflates and the tire acts like normal.

I would not be amazed to find that this is not a new idea either!

[lightarrow]

Every tire have its optimum temperature of working. If the T is higher, cooling them with water would have its benefict, if the T is lower, it would be worse. If you usually travel at high speed and many km in summer, it probably be good for tires to be slightly cooled, but you should be sure that road conditions don't vary. About mileage, is quite difficult to say because a lower tires' temperature decreases air pressure inside and this increases rolling resistance; at the same time gum becomes harder and this usually decreases rolling resistance...
Tires life should increase for the last reason.

[CliffordK]

I had a crazy idea about an inflatable band that is embedded in the "equator" of a tire. The idea would be that, when the car is cruising, the band is inflated so that it is pretty much the only thing in contact with the road - a bit like the skinny tire on a racing bike. When there is any braking or significant steering, the band immediately deflates and the tire acts like normal.

My old AMC had one of those inflatable donut tires.  Pretty odd stuff.  But, I don't think you'd get the durability you would need from an inflatable center bead.  Likely you would have to design it with a hard center bead and expanding tire around it.  The old bias ply tires apparently would expand significantly when inflated.

Perhaps our freeways of the future will have steel rails embedded in them.

Then when you want to travel for long distances, all you do is hop on the rail, drop down your solid rail guides, and take a nap.

[Geezer]

Mind you, the rolling resistance of tires is not really too bad to start with.

http://en.wikipedia.org/wiki/Rolling_resistance#Rolling_resistance_coefficient_examples