Need new tires

Snip>>>
This is for everyone with poor tires on thier car.
Remember the contact patch of each tire is approx. 4 square inches. That puts only 16 sq. inches of contact area between you and the ground. That aint a whole heck of alot at 75 mph. So please play it safe. Put the best tires that you can afford on your car. And, if you can only afford cheap tires, please take it easy.
Body panels are relatively easy to replace or fix. Skin and bones are not.
>>>Snip

I respectfully disagree

a 3000 lb car with 30 psi in the tires will have a contact patch of 100 square inches + a little for deformation of the rubber. It's physics. you can verify this by taking a piece of string and wrapping it around the contact patch, and then measuring the string. the tread width is around 9 inches (225mm/25.4) so take the total. subtract 18, divide it by 2 (to get the length of the patch) then multiply that number by 9 to get the contact patch of that tire. The length should be close to 4 inches for a contact patch around 32 Square inches per tire. This works for ANY vehicle with pneumatic tires. So the tire will give you a bigger patch when there's less air and smaller patch at higher pressures. Now I want everyone to tell me their tire pressures by measuring the contact path of their tires. speed and accuracy count.

GO


Collins
92 pearlie

OK, the overall length of the string should be 26 inches that makes the length of the contact patch "4" inches... That's better...

Darn that newfangled light beer.

Collins
'92 pearlie
'55 K&E log log duplex decitrig Sliderule

[SubaSteevo]

SVX girl, do not keep replacing 1 or 2 tires at a time. The different grips of the tires will eventually tear your transmission to pieces. As far as recomendations go, my car had Firestone Firehawks on it when I bought it. They were excellent under all driving conditions although I never had them in any more than an inch of snow. However, they were Z rated and wore extremely fast. I replaced them with Yokohama Avid V4's in December because I could not afford the AVS Db's at the time. The Yokohamas are very noisy at certain speeds (under 30, and at exactly 65 and 85), so noisy that I would have suspected wheel bearings but 30-64, 66-84, and 84+ are perfectly quiet Anyway the V4's are great in the rain but I have slid a little in the snow (ended up bouncing off a curb). Then again it was about 4" of snow and I was doing like 5 over the speed limit Just my $0.02

P.S. I run my tires at 36/32

Originally posted by Mr. Pockets


Adam, like others before me, I'll politely disagree with you. I have Dunlop D60-A2s on my SVX, and they performed very well in snow. Now, I also have a set of Nokian tires on steel rims for the SVX, but I've never actually used them. The first reason is that I never felt the need and the second reason is that I now store my SVX in the winter.

Anyway, the D60s handled the extreme winters of Vermont very, very well.

interesting.. i've been disagreed with a couple times on this one.. and from people who've undoubtedly experienced winters just as harsh as i have. It might be that my "all-seasons" (Yoko AVS dB's) were just too worn down by the time the snow showed up to be of much use. Anyway, if these guys say that you can do it on all-seasons, i wouldn't disagree with them.

if you live in an area which gets a significant amount of ice or your job requires you to be able to drive day or night, in any condition, it's probably worthwhile to run separate snow tires.. last winter i drove up my hill (about a mile long and a steep enough grade to make most people park at the bottom and walk up) through 3.5 feet of unplowed snow with no problems whatsoever.. the SVX just clawed its way up.. by the time i got to the top i couldn't see through the windshield since the defroster wasn't actually getting any air

just remember, once the snow hits, no matter how well your vehicle can hold a line through a turn, or what kind of snowdrift you can bust straight through, you never know how the other guy's car is going to behave. keep your eyes open

-adam

[Chicane]

I'll say this short and sweet, since nobody ever responds to what an incredible deal my current tires are, and how much they kick ass.

Go to SEARS.

Yokohama A550Vs.

Z-rated (up to 180mph)
Traction rating of AA (sticky!!!!!)
30k tread warranty
ALL SEASON PERFORMANCE
kick ass tread design
quiet on the highway
good in the dry, wet, and snow.

About 90 dollars each when I got them.

- Rob

[LarryIII]

Originally posted by Chicane
I'll say this short and sweet, since nobody ever responds to what an incredible deal my current tires are, and how much they kick ass.

Go to SEARS.

Yokohama A550Vs.

Z-rated (up to 180mph)
Traction rating of AA (sticky!!!!!)
30k tread warranty
ALL SEASON PERFORMANCE
kick ass tread design
quiet on the highway
good in the dry, wet, and snow.

About 90 dollars each when I got them.

- Rob

Rob,


How did they perform in the snow in Madison, WI last winter?

[immortal_suby]

I run my tires at 44/40 but they are on aftermarket 17" rims. I don't see how you can run low profile tires at the recommended mfg pressure and not expect to dent a rim or blow out a sidewall. I run the avs db's on my wifes svx at 40/36 to avoid destroying yet another set of tires before their time by wearing out the shoulders prematurely.
The max pressure rating on a tire is the cold rating - this allows for the expected increase in pressure with heat.

M+S ratings on tires are worthless.

Rob's svx is slow because he has cheap tires!

[Chicane]

Originally posted by LarryIII



Rob,


How did they perform in the snow in Madison, WI last winter?

Great! And they also performed well in the dry, and through a HUUUGGEEEEE rain storm I drove through last thursday night in IL. I drove through a 'puddle' about 1.5 ft deep. The water was ALMOST over my wheels.

- Rob

[Chicane]

Originally posted by immortal_suby
Rob's svx is slow because he has cheap tires!

Heh. Riiiiggght. I suppose I should go for a tire with a traction rating higher than AA. Like what?????!??!?!

- Rob

SVX Girl, I went with Yokohama Avid V4's as did someone posting earlier. My experiences have been very good. They are a lot less noisey than the ones I replaced. They are great in the rain and YES in the snow too. The best part is they are V-rated and cost me $70 something dollars each from Tire Rack.

[mbtoloczko]

Originally posted by immortal_suby


...

M+S ratings on tires are worthless.

...

Yeah, but its legal to drive M+S tires in the snow. I don't like the idea of being forced by a state trooper to chain up the wheels on my SVX.

I'm a bit of a tire geek, and there have been many threads on the subject previously, but I'll chime in.


The "max pressure" listed on the sidewall of the tire is NOT the number at which the tire suddenly becomes dangerous. Slow down and think about it for a few minutes, I'm serious.

The tires usually have a notation that reads something like this:

http://www.tirerack.com/images/tires...rkings_new.gif

The thing you read on the side of the tire that indicates "max pressure" is the North American Load and Pressure Marking. It tells you what the maximum load rating of the tire is, and at what pressure it achieves that maximum load. If you go above or below that max pressure, the load capacity of the tire drops. In other words, it's the pressure at which the air and the rubber work together to achieve the most strength and stress capacity. The rolling resistance is also typically at its lowest reasonable point here, so gas mileage is improved.

Of course, whether you want to run near the max pressure depends greatly on the design of the sidewall and the tread compound of the tire you are using. High end sport tires with very stiff sidewalls will give you great steering response and communication without having to inflate the tires to near their max load, because their load index rolls off very gradually as you decrease or increase tire pressure... this is because the rubber itself is doing more of the work of managing and distributing the load, rather than depending on the air pressure to reinforce and to carry the majority of the weight.

Sporty all-season tires (my preference for all-around use) achieve more of their load rating from air pressure, so they typically handle best around the max load rating pressure, in my case I run 44psi in the front (the "max" pressure on the tire) and 3 psi lower in the rear to ensure proper center diff operation. This results in snappy steering response and very predictable behavior when driving aggressively, far more so than if I were running pressures in the low 30s. Total lateral grip is essentially the same at either pressure, but the slip angle and the communication of the tire to the driver are much improved at higher pressures. Tire life is also better at higher pressures, I have 22k miles on my RE950s and I've abused them in every way that it is possible to abuse a set of tires... track use, autocross, high speed commuting, on snow and ice trying very hard to get the back end to step out, driving extensively OFFROAD at high speed (60+) on dirt and large chunk gravel, etcetera etcetera. I've driven them so hard the edges of the tread blocks have feathered upwards from the heat and shear force. I probably have about 10k miles left in them before they have to be thrown away, to me that is outstanding considering my pattern of use. They are wearing evenly from edge to edge, and yes I've done the chalk test.

I consider the doorjamb rating to be a complete waste of time... that's put there by lawyers and marketing screwheads, not by engineers. Remember, most car reviewers that have columns read by a majority of the buying public value "ride quality" over performance, they're the kind of dumbasses that would give the PT Cruiser the "Car of the Year" award.... oh wait, that already happened.



So, that's my $0.02. Anything from about 32psi up to the max load rating of the tire is good, and on some tires (soft crappy "touring" tires) you have to run higher than the max pressure to get any feeling out of them at all.

Race tires are a different story as well... In SCCA autocross, the fastest stock WRX in the southeast US (Tom Hoppe) runs crazy pressures like 35 in the front and 60 in the rear. Go figure.

[Subafreak]

I don't drive my SVX in the winter becouse RE730's SUCK in the snow. When I first put a set of RE 92's on my Turbo Legacy they where awsome in the snow, after about half life I put them on my Legacy wagon and they were deadly in the snow. I will probly get some Blizzaks for it this winter so it can make it up the drive way in 14inchs of snow like the Loyal. Hopefully.