View Full Version : * reduce your tire pressure when snow is coming down hard?
blue mountain raider
Dec 17th, 2007, 02:57 PM
so before i left for blue yesterday (sunday) i took my tires down to 13-15psi. guess what, it made day and night difference. only time i got stuck was in blue parking lot where snow was deep and the car was parked on a slight decline. but eventually got it out with some help.
my car is FWD. on the 400 hwy the car didnt fishtail when changing lanes, speeds up to 100kph, yeah too fast but i wanted to see how far the tires would go (all season).
anyhow just thought i'd share this in case some fellow RFDers dunno.
but again, no amount of AWD and deflated tires can conquer human stupidity. ie, going 120kph into hwy on/off ramp, etc.
Jim123
Dec 17th, 2007, 03:22 PM
Not according to the NHTSA.
11. Should I lower my tires' pressure to get better traction in the snow or off-road?
You should always keep your tire pressure at the psi level recommended for your vehicle by the vehicle manufacturer. Lowering your recommended tire pressure by even a few psi may results in a smoother ride, but it can lead to tire failure. Note: some vehicle manufacturers may provide a lower recommended tire pressure for lower vehicle loading conditions, e.g., if there are only 1-3 occupants in the vehicle. This should not be construed as recommending a lower pressure for use in snow or off-road.
http://www.safercar.gov/tires/pages/TirePressureFAQ.htm
AzN_RiverdaleCI
Dec 17th, 2007, 03:23 PM
Not according to the NHTSA.
http://www.safercar.gov/tires/pages/TirePressureFAQ.htm
Well said, bmr @ owned.
blue mountain raider
Dec 17th, 2007, 03:30 PM
it only says possible tire failure, nothing about better traction. which would you want: possible tire failure or getting stuck in snow from spinning out?
rayner55
Dec 17th, 2007, 03:44 PM
Your gonna be paying a hell lot more for gas as well.
Under-inflated tires cut fuel economy by 2% per pound.
Source: http://www.allthingsfrugal.com/f_saveongas.htm
You just lost 30%+ on fuel economy right there.
blue mountain raider
Dec 17th, 2007, 03:54 PM
i know deflated tires kill mileage. but i only do it when weather is bad and i need to go out. i will be inflating my tires soon
deflated tire = more surface area = more traction.
its like saying saving a few cents of gas and going out in inflated tires in a snow storm, then getting stuck in snow then paying $200 get get car out.
rayner55
Dec 17th, 2007, 04:01 PM
i know deflated tires kill mileage. but i only do it when weather is bad and i need to go out. i will be inflating my tires soon
deflated tire = more surface area = more traction.
its like saying saving a few cents of gas and going out in inflated tires in a snow storm, then getting stuck in snow then paying $200 get get car out.
You make it sound like cars will spin out if they dont lower their PSI. Lowering PSI as well increase odds of your Rims bending/warping when you hit potholes, then that itself is several hundred dollars should it happen.
Winter tires is good enough in my opinion. This cost more money, more hassle, and not advised by safe driving institutions.
KevC
Dec 17th, 2007, 04:04 PM
i know deflated tires kill mileage. but i only do it when weather is bad and i need to go out. i will be inflating my tires soon
deflated tire = more surface area = more traction.
its like saying saving a few cents of gas and going out in inflated tires in a snow storm, then getting stuck in snow then paying $200 get get car out.
i thought snow tires were narrower to "cut" through the snow, as opposed to performance tires that are wider to have more grip?
Pete_Coach
Dec 17th, 2007, 06:29 PM
You make it sound like cars will spin out if they dont lower their PSI. Lowering PSI as well increase odds of your Rims bending/warping when you hit potholes, then that itself is several hundred dollars should it happen.
Winter tires is good enough in my opinion. This cost more money, more hassle, and not advised by safe driving institutions.
Also, lower tire pressures allow the tire to flex on the rim significantly more and there is a potential of the tire coming off the rim when cornering.
i thought snow tires were narrower to "cut" through the snow, as opposed to performance tires that are wider to have more grip?
Somewhat right but for sure much better than lowering tire pressure. Snow tires of the same size a your all seasons are fine (and most likely recommended by the OEM), the aggressive tread is what bites into the snow. What the OP thinks is traction is probably only tire deflection on the rim
ES_Revenge
Dec 17th, 2007, 07:33 PM
i thought snow tires were narrower to "cut" through the snow, as opposed to performance tires that are wider to have more grip?
Yep. So normal or even higher-than-normal pressure will make it easier for the engine to power the car through deeper snow, but lower-pressure (and more contact area) will increase traction on slippery surfaces (which is what I think the OP is trying to say).
So it's once again like everything, a trade off. You trade plowing-through-snow performance for less wheelspin/more traction on flat/plowed/packed snow/icy/slippery surfaces.
Personally I think it's just a waste of time fooling with pressures like this. It's one thing if you're at the drag strip needing to get a better 1/4 time, but like setting different pressures for every different surface you encounter is a lot of hassle, and isn't really practical.
Set your pressure to what's recommended. Change by a few psi if preference demands it, but don't go over or under inflating by like 10-20psi just because it might help you somewhere along your drive. It would be nice if you could change tyre pressure at the press of a button in the car, but you can't so I wouldn't bother.
googoo
Dec 17th, 2007, 07:55 PM
"i thought snow tires were narrower to "cut" through the snow"
Ding Ding we have a winner!
More weight on a smaller contact patch means the tires actually cut through the snow better.
Goo
dealhunting
Dec 17th, 2007, 10:55 PM
Lowering tire pressure bellow manufac specs also increases danger of road hazzard damage to tire and rim. ie: blow outs, tire rolling off rim, tire spinning on rim, etc.
If I were stuck and tried everything else, decreasing tire pressure to widen the contact patch may be an option, but I would re-inflate back to specs ASAP.
kenchau
Dec 17th, 2007, 11:20 PM
OP, 13-15psi?!?! Are you insane, that's practically like no pressure at all...considering that standard pressure is usually about 30+psi.
I understand what the OP is saying though, however, I wouldn't lower it to such an extreme - mind you I don't know what the standard recommended tire pressure for the OP's vehicle is. I do know that one of my old cars back then when the recommended pressure was 32psi, I would set it to 30psi just for a bit of extra, but I wouldn't go to extremes - unsafe.
That said, you guys have to remember that depending on what the temperature outside was at the time your tire pressure was set, your tires may be under or over inflated at this very moment because it fluctuates quite a bit with varying temperatures.
AudiDude
Dec 18th, 2007, 12:50 AM
deflated tire = more surface area = more traction.
It's a radial tire, not a bias ply drag slick. Reducing pressures results in cupping , less surface area, and stresses the crap out of the sidewall which can cause your belts to shift and fail. For all of our safety please by snow tires.
http://static.howstuffworks.com/gif/tire-problems.jpg
cwb27
Dec 18th, 2007, 01:07 AM
You can buy pretty much any size snow tires, but the wider the tire the more of a 'plow' effect it will have rather than a 'cutting' effect (as mentioned in a previous post) as found in narrow tires.
You need to strike a balance between contact area and traction, personally, I buy snow tires.
jason9945
Dec 18th, 2007, 02:21 AM
Well, I'm sure this idea is great until your tire falls off the rim while doing 100 km/hr on the highway (in the snow too)
nickia
Dec 18th, 2007, 02:28 AM
another classic example of that people should never trust what they read online.:lol:
robertalan
Dec 18th, 2007, 05:29 AM
The scary thing is that someone is just going to read the title of this thread, and then drive the rest of the winter like this. The title should be edited.
hytong
Dec 18th, 2007, 08:32 AM
Lowering the pressure is one way to help sinking and get the vehicle out of stuck over deep snow, sand, etc. But return the pressure to normal once you start driving, beside the fuel economy, there could be too much sidewall flex and heat if pressure is too low