high tire pressure and wet roads
 

In my 91 civic hatch I have had a few close calls on wet roads. Thought you all should know. I was running 44 front/42 rear, on newish 165/70/13 all season tires.

incident 1: fast decel to a stop light, lost front traction, then e brake to a diagonal stop. :eek:

2nd, today: someone pulled out in front of me while i was going 60, fast decel in 5th gear to 35 and lost front traction momentarily.

now I have 35 front/32 rear and everything is fine.

All you high pressure vets can drive accordingly i am sure, but what do you do in an emergency and you have no traction? :rolleyes:

everyone needs to be careful...

our lives are more important than our gas mileage. ...i think.

I think everyone here with high pressure should test their traction on the wet, if not already done, just to see what to expect in an emergency.

preesure=pressure (measured with warm tires)

I lowerd mine a little when it snowed pretty heavaly so that i wouldent get stuck. I put mine to 44 from 54 because i was loseing traction. The only reason though was the snow but when it rains i just increase my folowing distances by 2-3 secounds on the interstate and a little less in the city. I just know that i have to be alot more carful when it comes to the weather wit the higher pressure tire so i drive like it. Also its not the safest thing in the world to do but most kids in my age group (17-19 ish) drive freakin crazy so this is my rush knowing that a tire could exsplode or lose all traction.:eek:

Thats how they get all those great car sliding shots in Tv and movies .. high pressure and wet roads.

Good info! My pressure is set at the factory suggested 23 PSI front and back.

I'm going to bump it up to the sidewall pressure to see what happens.

My first concern is the ride. Even at 23 PSI my Sidekick rides VERY VERY hard. Almost to the point of being uncomfortable. Can only imagine the sounds my high mileage suspension is going to make and the handling with a truck that is only 1900 pounds when I add more air.

This is a valid point. Traction on loose surfaces will be worse with high pressure also (eg gravel).

If you choose to run high psi, you have to compensate with your driving in those conditions: more caution, lower speeds, greater following distances.

I've understeered my car (mildly) around a few corners in the wet with the high PSI. But it was expected - I was conserving momentum, and didn't brake before turning.

My wife and I took a trip up to NH last weekend -- slush, freezing rain, salt and sand. Tire pressures were at 38/40 and everything was fine. The only time I lost traction momentarily was when making a sharp left turn across the piles into a driveway to turn around.

Road surface quality helps a lot. MA roads are generally the worst in the region, but I'm fortunate because most of my newer hypermiling route to work has recently been repaved. :) On my former route, the car would go airborne on frost heaves, so high (or even normal) pressure in rain was very dicey.

I have had no problems with traction on wet roads despite maintaining my Michelin Harmony 175/70/13 tires at 60psi and I take the corners pretty fast. Now that my tire's tread is getting low after 60,000 miles, I have to take it easy when the water is lying thick on the pavement, but they are perfectly fine on normal wet roads.

I never had probs with fast corners either.

stopping short is where i would be more concerned with high pressure.

agreed on increased following distance, but

what if a deer runs in front of you, or someone cuts you off or some other totally unexpected event?

that is the point, you can only anticipate so much. :o

Good point about the deer because a few months ago that happend. I ended up hiting it but it wasent because of loss of traction it was just he jumped out from a froresty aera on the side of the road maybe 30 feet in front of so i hit the breaks hard and it didnt really skid or lose any traction. I was doing 60 without loss so thats pretty good.

I constently test my stoping distance, and traction, that is how I ended up in the ditch last winter 1/4 mile from home, it was a nice straight streach with hard packed snow/ice, and I locked up my brakes while going about 30mph, spun around and ended up almost rolling the car, that is why this year I bought 4 new snow tires and passed that set on to the crx, these new snow tires have 50psi in them, and it was only icey on new years day, so I haven't had a really great chance to check them, but on hard packed snow covered roads, they seem to do just fine.

yeah. good idea. I need to do that soon. priced them at 160 for the set of 13inch. not bad.

I have no problems with quick stops. When stopping on smooth dry pavement with my current tires, it is practically impossible to lock up the wheels. I am getting better cornering/braking performance from my 175/70/13 tires at 60 psi than I did with my previous 165/70/13 tires at 38 psi.

Your Sidekick rides very firmly because of the high(er) spring rates...NOT because of the higher tire pressure! Air pressure has taken a lot of blame for ride quality/tire performance. There are enormous forces at work on the tire contact patch(road contact area) when maneuvers are undergone ; ie, braking and/or turning. The actions of the tread "ribs" determine how your vehicle is gonna react. Air pressure determines how your tire behaves...it is the foundation of each tread rib! Less P., more flex. More flexing, less traction...more heat build-up and greater wear rates! Weight has little to do with today's ranges of tire sizes.
If it were my ride...I'd put 40 psi (cold) in all of 'em...and check 'em once a week! So, the ride suffers a tiny bit. With today's radials, a belt prevents tread "bowing", the traction is better (regardless of what you've heard) and the tread wear almost disappears! A flat, even tread patch is the key.
Wet is wet...slick is slick. "Marbles" are marbles! A softer tire isn't gonna gain that much more traction under unusual conditions...and will run hotter / wear out faster! The factory recommended pressures are a compromise... they want you to buy new tires soon...!
Life is a compromise...and your life depends upon your tread contact patches! At 60 MPH, your future depends upon 4 patches, each about the size of your (fingers closed) palm! Treat 'em right! Roll on! :cool:

Ted, The fact is my car will stop short with the factory rec pressure 35/32, not with 44/42 hot.

Ive been running max sidewall or better for years. No problems what so ever. Give me a chance and I can break any tire loose. Be it a FAS or under power. Rain, snow or dry. I was getting some understeer in the Civic this weekend heading into and thru some really sharp right and left turns FAS'ing. Not wanting to burn the coast to much I wouldnt set the car up with the brakes or throttle. Weight **** can be a powerful thing. :)

Dealing with understeer, oversteer, sliding and general loss of traction is a everyday issue in driving a car.

Learn to drive, deal with it,,,, OOOO and have some fun!!!

psy

The reduced contact area on the rubber compound increases the sheer forces on the rubber and if too small an amount of rubber is making contact with the road then the rubber can not withstand the braking forces and it sheers off causing wear and loss of traction. Too low a pressure and the tire deforms also reducing the ability of the tire to displace the water on a wet road and you also loose traction when trying to stop. A lot depends upon the weight of the vehicle - high pressure on a light vehicle will make the contact patch too small but not so much on a heavier vehicle. Lower pressure will also make your tires warmer from tread flexing and that also helps to provide more traction on the road. Any way you look at it . . . it's a tough call as to the "right" pressure in the tires.

Budomove: When you experienced the problems you described, had you been running your tire's at the higher pressures for a very long period of time, or were they just recently increased. What I got wondering about was if the tire pressure was increased, for a period of time, then the tire tread should be getting worn to where it has contact all across the width of the tire. However, when first changing, it is clear from my rear tires, that it was riding on less than the full width, initally, but it seems to be getting more evenly worn, now that the tires have been running at the higher pressure, for a while.

Any thought's?