Incorrect Information re: Tire Pressure in Efficiency Mods

[Xringer]

Years ago, I got my first car with fat 16" tires. It was a 1991 Plymouth Laser RS (2.0L)
This one actually, (It's a Mitsubishi Eclipse under the logo)


It had the fancy Goodyear tires that could pull 0.9 Gees on the skid plate.
The thing handled like it was on rails (as they used to say).
But, when it snowed or rained (or the combo), good control went out the window.
Those fat tires were like toboggans.. Did not want to respond to the steering wheel.
If you got in a truck ruck, you had to go where the truck was going!

Since the small engine version of the Laser used 14" tires, I was able to pick up some of those tiny rims for my car..
I put narrow GoodYear F-32 snow tires on those wheels, and found they were great for almost any wet or snowy driving conditions.
My buddy liked how well they worked and got the same setup for his Dodge Sheath.
Before getting the F-32s, he was too terrified to drive in snow..


Later on, I found my hot-rod 16" Goodyear tires really liked to hydroplane
during a real heavy rain storm. (Like in central Texas).
I became a fan of the 'Rain Tire' and later the HydroEdge..


Anyways, my experience says, in snowy areas, avoid Toboggan tires..

Living in this snowy area is one reason that I like to keep my tires up around 44 PSI.
Let them get too low, and they start putting down a big foot print, just like a freakin Toboggan..

[wdb]

I had OEM Bridgestone RE-92's on my Subaru Legacy that were horrible in the rain. I replaced them with another set of Bridgestones, can't remember which anymore, but they were absolutely awesome in the wet. Same tire size; in fact the replacements were a hair wider.

Wet traction is not all tire width.

[radioranger]

My Ranger had about 27 PSI in the tires when I bumped it up to 32 the performance difference was very noticable, cant believe I didnt check it more often . plus almost 2 more MPG . I think if you are running rough roads you are better off around 32 , 34 psi , anything over and you definitely feel the shocks taking a beating, especially in a small truck! although smoother highway travel can probably go up to 36 psi , just my opinion

[Xringer]

I have not checked my Ford's tired for months.. I hardly drive at all in the winter anyways.
I only put on about 15 miles a week so I can wait until spring before airing up again..

[ProDarwin]

Long, old thread, so this has probably been covered.

RE: The original post: In the street tire autocross world, if it's raining, it is commonplace to lower tire pressure by ~10psi. Overinflated tires are not good for wet traction. I see the 65+ article has been change to reflect "mixed opinions".

[Xringer]

Originally Posted by ProDarwin

Long, old thread, so this has probably been covered.

RE: The original post: In the street tire autocross world, if it's raining, it is commonplace to lower tire pressure by ~10psi. Overinflated tires are not good for wet traction. I see the 65+ article has been change to reflect "mixed opinions".

I've been in some bad hydroplaning situations, so I kinda believe this test.
Tire Tech Information - Air Pressure vs. Wet Performance

"Members of the Tire Rack team had the chance to experience the effects of air pressure on wet performance at Michelin's Laurens Proving Grounds. Drivers were given the opportunity to compare identical cars on a wet-handling course with the exception of one car having four properly inflated tires (35 psi) and the other car having significantly underinflated tires on the rear axle (25 psi).

While driving at the edge of a tire's ability in wet conditions is challenging, the car with the properly inflated tires provide handling that was predictable. Driving the car with the underinflated rear tires proved to be much more difficult to drive and forced the driver to slow down to retain control, producing lap times that were several seconds slower than the properly inflated car.

While tire manufacturers can develop tires with great hydroplaning resistance and wet traction, poor maintenance of tire inflation pressures can make a great tire awful."




Guess which tire is underinflated..

[ProDarwin]

Rich,

Hydroplaning vs. wet traction are two different scenarios (well, one is an extreme case of the other). I was referring to wet traction, not hydroplaning. Its entirely possible to have a tire inflation pressure that produces poor performance on wet pavement but resists hydroplaning. TR's test is accurate, but doesn't cover all conditions.

[gone-ot]

...luckily, it does not rain "all the time," while FE-conscious driving typically is an "all the time" process.

[Xringer]

I don't mind it, when my tires spin a little, while taking off from a stop sign.
Since I don't pull boat trailers up wet ramps these days, no problemo..

But when I'm doing 60mph, while there's standing water on the roadway,
and I hear my engine race, and see my RPMs speed up.. While my speed is actually decreasing..

That worries me a lot.. Because I know my steering wheel isn't going to work real well,
until my front tires get back down on the pavement.

The other reason I like higher tire pressure, is the handling is better.
However, I don't drive on bumpy roads very much..

I'll bet the faster lap times on the 'wet-handling course' wasn't all about hydroplaning.
They also had to make a few turns on Track 3.. AKA handling..

[Xringer]

Originally Posted by Old Tele man

...luckily, it does not rain "all the time," while FE-conscious driving typically is an "all the time" process.

Since I only drive about 12 miles a week, I've pretty much given up on trying to save gas..
I just stay under the speed limit, while watching the MPG on hills etc.

Main thing I have to stay on top of, is adding some Sta-Bil fuel preservative to the tank,
after I fill up every month or two..