I upped the PSI to my tires from 29 to 35 and...

[trebuchet03]

Originally Posted by johnpr

that hydroplaning speed equation is great, but doesnt tread pattern affect hydroplaning also?

That equation comes into play as soon as you exceed the tread capabilities of a tire (more likely on worn tires). Think of skipping a stone on a pond - there's no tread, but there's a certain speed you must reach before it stones will start skipping (hydroplaning) on the water surface. It's also worth mentioning that the equation is an estimation

[Chris D.]

I read that police site and desided to form my own opinion and take a shot at it..

my tires are in good condition and ive been thinking alot about rolling resistance and some of the techniques used when autocrossing and this mite be the ticket..

I'll rattle off a tanks worth and see if I get numbers and if I can withstand the ride quality of the higher pressure..

60 front 55 rear..

Ive read a few studies and seems the norm tire pressures of 32-35 are pretty much a safe way of getting more comfort and less out of the tires..

I got off the phone from a rep at Toyo that i'm friends with and he said he mite help me out with some tires for a study.. So we'll see, i wont hold my breath..

[Chris D.]

Heres a good 450 miles worth of high pressure reporting..

I like the feel, firmness with agility on the road..
coasting seems to keep momentium for much longer..

I'll be keeping an eye for wear by checking depth every so oftin, I have
my numbers written down per tire before and will be keeping track of that..

inner middle and outter depths measured, FYI..
so far their all even.. taken from 3 sides of each tire I've got a great alighment..

time will tell

[Daox]

Thats the same thing I did Chris. I was a bit hesitant at first, but its been about 6 months now. My tires look great, car rolls forever, and handling is a bit sharper. The only downside was winter snow traction was worse. However, that never got me stuck this winter, and we had record snowfall this year. Now its getting warmer and I'm loving every minute of it.

[Otto]

1.) Hydroplaning: In some aircraft (cars probably the same for the same reasons), hydroplaning speed (expressed in pounds pressure and miles per hour) is 9 X the square root of the tire pressure. So, with 36 lbs. pressure, square root is 6, so 9 X 6 = 54 mph. If you increase tire pressure to 49 lbs., then 9 X 7 = 63 mph, etc.. Increase tire pressure and you increase hydroplaning speed.

2.) Your tires get pressure increases that spike every time you hit a bump or pothole, so they can take a lot of pressure. OTOH, increased baseline pressure puts them closer to ultimate failure pressure upon meeting that fatal pothole. So, if you increase the pressure, be more careful about avoiding potholes, etc..

3.) Per years of empirical evidence from posters here, higher pressure seems not to be a problem with tread wear or tire life, assuming the tires were of good quality, with proper alignment, etc..

4.) Alignment is a big deal for tire wear, mileage, and handling. Use the thread trick to check and align your wheels. Vastly cheaper than commercial methods, and car tracks straight ahead, hands off, at 110 mph.

5.) Noisy tires are probably fuel-inefficient tires, as the noise is probably a product of (inter alia) tire squirm against the pavement, which is surely generating heat as well as noise. (Higher temps also wear out tires quicker, so you're paying for that, too.) I'd hazard a guess that for a given tire, the quietest performance is also the most efficient, and varies with pressure. This would be an interesting experiment.

[trebuchet03]

Chris - for doing your own test

assuming the tires were of good quality, with proper alignment, etc..

That's probably the most important thing here.... Old rubber isn't happy rubber

And an interesting point about noise... That deserves some investigation methink s

[Otto]

Originally Posted by trebuchet03

Chris - for doing your own test




That's probably the most important thing here.... Old rubber isn't happy rubber

And an interesting point about noise... That deserves some investigation methink s

In re: Noise vs. rolling efficiency

On a bicycle (easy to test and to hear the noise) do a roll-down test on a hill, with high tire pressure vs. lower tire pressure. We know that higher pressure gets us less rolling resistance, but does it bring commensurate noise reduction? In other words, is the presumable noise vs. quiet directly correlated with rolling efficiency?

It would be interesting if one could develop some sort of reasonably accurate rule of thumb.

Noise and heat are unwanted byproducts of inefficient rolling

[trebuchet03]

Originally Posted by Frank Lee

Worn out tires roll easier.

Worn out isn't the same as old

[trebuchet03]

Originally Posted by Frank Lee

Most of the time it is.

No, old and worn are two different things.... My spare tire is 8 years old, but has perfect tread.... That's the point - plenty of people ride on old rubber... Take a peek the next time you're in a parking lot

Originally Posted by Safety Research & Strategies, Inc., 2005

Following Firestone, SRS began tracking cases involving “aged” tires—tires older than 6-years—that have
failed catastrophically causing crashes. With more than 65 documented cases, several patterns are
emerging. Nearly one-third of these cases involved spare tires, approximately one-third were tires
purchased used. The remaining cases involve tires that were mounted on little-used sports cars, old stock
sold as new, or their histories are unknown. What links all of these cases together is the fact that the tires
have ample tread and appear safe when they are put into service.

Old != worn

and, I should probably replace my spare tire

[trebuchet03]

Originally Posted by Frank Lee

Whatever. Worn out tires roll easier.

I don't deny it It's just not pertinent to the discussion at the moment... In any case - have a beer