jimbo1mcm

I usually keep 32 psi in the front and 35 psi in the rear of my Michelen MXV's. I drove through a moderate rain event today and was frankly surprised at the hydroplaning effects. It bordered on unsafe. There was considerable pooling on the roads and I actually saw an older S Class bounce off the median and spin into the center lane, one car ahead of me. I think I will move the pressure down to about 27 and 29. Anyone have a similar experience?

LNL

I'm not sure that the pressure is the issue. Some tires shed water better than others. I've changed tires on other cars after bad handling experiences, and a better designed tire makes all the difference.

The MXV4's are ranked 10th out of 16 (6.4 out of 10) on Tire Rack's user survey for hydroplaning resistance (MXV4+ is ranked 8th at 6.7). http://www.tirerack.com/tires/survey...ll&sortValue=3

I run Goodyear Eagle F1 GS-D3 summer Z-rated performance tires on my car, and they are excellent in the wet (#2 per Tire Rack's survey, 8.9 out of 10). http://www.tirerack.com/tires/survey...ll&sortValue=3

I realize that the "ratings" are subjective rankings, but they are a good guide to look at when selecting tires.

Lou

KosherBenz

I agree 100% Goodyear Eagle F1 GS-D3 are amazing in Wet or Dry. They are by far my fav choice for tires.

X72

jimbo1mcm; I agree with LNL that the MXV4 is much weaker than higher performance tires in wet weather. The MXV4 is an all-season tire (also weak for snow traction) that is biased towards long tread life and low rolling resistance.

3 questions.
How many miles on the tires?
How much tread depth do you have?
How fast where you going?

AndrewAZ

When you say pooling on the road was happening no tire no matter how good it is will prevent hydroplaning when you have water pooling mixed with med/high speeds. You just have to slow down and drive at speeds that are safe for the current road conditions and stay out of the right lane since the water runs from the center of the road to the right and usually the right lane has pooling on the far right side of the lane.

sosh

Keep in mind that the optimum speed for hydroplanning is 10X the square root of the tire pressure. There of course are other factors such as tread design, tire size, vehicle weight, etc. However if you avoid the speed indicated by the above formula within 5 MPH on either side you will minimize the risk of hydroplanning.

stevec32

Whatever you do don't reduce the tire pressure!!! The lower the tire pressure the slower the speed that the car will hydroplane. It is very close to 10 times square root of the tire pressure in mph. So if you have a 36 psi tire that tire will hydroplane at anything over 60mph period, every time you are over that speed in water deeper than your tread depth. If the tire is 25 psi the hydroplaning speed is 50 mph. Also once a tire is hydroplaning it will continue to hydroplane to and even slower speed than existed when the hydroplaning commenced. It doesn't matter who builds the tire it is just a factor of tread depth. It's true that some tires will handle better in wet than others, but only in water less deep than their tread depth. Tread design has nothing to do with hydroplaning only tread depth deeper than the pooled water will overcome hydroplaning.

Just my 02 cents
Stevec32

sosh

See my previous post. Hydroplanning is not any speed over the formula result but within approx 5 MPH on either side of that number. I never suggester reducing pressure but did suggest staying away from the speed noted by applying the formula. And, yes tread design does have an effect on the hdroplanning as does tread depth. In any case standing water on a roadway is not a good thing.

stevec32

You wrote

"Hydroplanning is not any speed over the formula result but within approx 5 MPH on either side of that number. ""

So are you suggesting you need only exceed 5 mph over the hydroplaning speed and you will avoid it?

If so you need to tell NASA right away. Because they have it wrong

jimbo1mcm

Didn't measure the depth, but the tires have about 15,000 miles on them, so they should have been in pretty good shape. The road conditions were fairly unusual. In the course of my trip up the Jersey turnpike and Ct turnpike I saw 3 accidents and counted about 5 front end pieces sitting in the middle of the highways during my 4 hour trip. Thanks for the responses. I will keep the pressure at the current levels. I also usually move into the center lane and get a little spacing in order to have maneuvering room. I needed to dive to the right lane to avoid the S Class spin out in front of me. Glad I had the room.

egxpimp

I think it lies more on accelerating, breaking, car control and psi on the tyres. I have run on slick tyres ( i think the psi was 36) up to 160mph without any problems under hard raining conditions (at a closed track before i get flmaed on)

I think it is time to change your tyre brand. You sure you were hydroplaning at such low speeds? the E class is a pretty heavy car....i'm very surprise your having problems at such low speeds with it Perhaps you were a bit paranoid ? and felt steering feedback on the wheel ? Was it pulling the front end to the left/right ?--under rainy conditions you shouldnt counter steer to fast.. just follow the front end and then pull carefully to wherever u want to steer the car.

Flash Gordon

I absolutely agree! When you have a pool of water, I don't care if you have Formula 1 rain tires, you will hydroplane! Prudent drivers will slow down or go around the pool.

X72

Agree with Flash Gordon's advice to slow down. US roads are not well maintained. Heavy truck traffic causes ruts in the road that allows water to pool.

The MXV 4 starts out with 10/32 inch tread depth (8 mm). At 15k miles, the tires may be already 50% worn (4 mm). You can get an inexpensive tread depth gauge to verify my hypothesis.

The difference between you and that older S class may have been that your vehicle has ESP (stability control) and that older S class may not.

Have already made most of my tropical storm preparations so I had time to play online.

DStanley

I change my tyres on average around every 2 months.. and I find Michelin Sports VERY POOR in the wet, the best tyre for the British weather are Continetal Sports (But very soft)