SNOW TIRES

markbuck

The only reason I prolong this argument is because of the laws of physics.

Assuming the same coefficient of static friction between rubber tires and the pavement, the stopping distance is the same regardless of mass.

garth

because according to your last post, an 18-wheeler with the same tires as your Silverado would have the same stopping distance.

COME ON! there's more than one factor at play here- tires, brakes, mass of the vehicle, etc...

davechen

markbuck: Thanks, I was eyeballing the Z-chains. I think I will get them as "backup" for my Subaru Outback in really bad conditions.

garth & markbuck: Being an enginerd, I have to put my 2 cents in regarding stopping distances & tires, etc. I have to agree with garth, there are very many variables that affect stopping distance other than just mass of the car.
I think the biggest sticking point is that the maximum possible force to stop your car is NOT linearly related to the weight of the car (as a basic physics equation, weight*coefficient of friciton = normal force, would have you believe).
In other words, double the weight simply doesn't result in double the stopping power available.
If your car were exactly the same, except it weighed double, the tires rubber would deflect, heat up, and portions of the contact patch would effectively slide, plus your brakes would not be able to handle the stopping force (ie: they wouldn't be able to get close to lockup), plus your car would dive forward even more (because the center of gravity is higher than the tires), placing even higher *percentage* weight on the front tires than before.
The important thing is to know how your particular car handles in all conditions and drive accordingly.
Dave

igloomaster

again, i can only reiterate from my experience:

my '94 RWD Ranger pick-up (with sandbags and studded snows) handles better and is generally safer in the snow and ice than my lightweight '99 FWD Honda Civic.

dudleyr

Which would be better in the snow if they both had studded snow tires, and extra weight over the drive wheels?

igloomaster

That's hard to answer - I couldn't increase the weight over the drive wheels in the FWD Honda even if I wanted to, though I can use narrower studded snows on both vehicles.

I'd rather have my sand bags over the back axle to help with "digging + pushing power", and the use of 4 studdies helps the front wheels with turning. To me, I'd rather have the vehicle "push" the weight rather than "pull" it. If a RWD vehicle starts to spin a bit, I feel like I can control it and stop it better. I like the way the steering is freed up in a RWD vehicle.

I had a scary experience in my first Civic Hatch a few years back. It was during a blizzard. I was driving very slowly, carefully, methodically, and safely down a major highway (snow tires on too). Suddenly the car decided to spin and slide, and did a complete 360 and more. My [non-permissible content removed] end wound up perpendicular to the jersey barrier.

Luckily, nobody was injured, and the car was unharmed.

The only way I can describe that feeling, is the feeling you'd have as a kid, when you are in a plastic sled and you hit a patch of ice at the bottom of a hill. Loss of control - completely.

garth

maybe you hit a patch of ice?

do you think the same thing would have happened in another car? in other words, what was it about your Civic hatch that makes you believe it contributed to the loss of control?

maybe it was too light (what's a Civic hatchback - 2300lbs?) however, economy cars usually have really narrow tires, which helps a great deal in snow...

igloomaster

my personal belief was that the weight of the vehicle contributed to the loss of control...

i guess i look at it this way: the civic is more apt to slide and control is more apt to be totally lost because the vehicle is light. it's more difficult for that to happen in the Ranger [though certainly not impossible]. if i could drive both vehicles at the same slow pace, and encounter the same exact weather conditions, i believe the honda would slide longer and farther than the truck. the weight of the truck would help slow it down in a spin.

markbuck

Really notice the difference in driving a long bed crew cab vs a short sports car.

The crew cab was really hard to pitch out the rear end, and was not deflected much by big old ice dams and snow drifts. The 168" wheelbase really made it more forgiving when going straight...

garth

igloomaster, i think you have it backward. the weight of the Ranger would help to keep it from sliding; however, once it breaks into a slide, its greater intertia would keep it sliding farther than the Civic.

i think the point i was making about tires is valid, though - many little front drivers are quite good in snow because their narrow tires cut through to the pavement.

MY front driver, OTOH, has fat pseudo-sports car tires (it's an integra), and slides all over like a greased pig.

igloomaster

well, i'm not a physics expert by any stretch of the imagination......you might be 100% right based on the math. not sure about that. Where is the 'greater' inertia coming from, if the vehicle is not moving that fast? What about wind resistance? It seems logical to me that a hockey puck is going to slide faster and farther across the ice than a cast-iron stove, if somehow they were both slapped with the same force.

All I can speak from is personal experience. I've tried my damned-est to get that pick-up truck to spin out and slide and whatever....so hard to accomplish RWD fun with 4 studdies and all that weight. I love the opportunity a wide - open parking lot presents in a blizzard.

garth

inertia is essentially speed times mass (hey, if i messed up the formula gimme a break - been a while since i took physics)

so, a moving object with greater mass (stove) would have greater intertia than one of lesser mass (puck), provided they're moving at the same speed.

you're correct that if they were slapped with the same force, the puck would move faster - but with vehicles, you're not slapping with the same force. your Ranger's engine is applying more force than the Civic to maintain a given speed on the road.

in sum: at the same speed, a heavy object has more intertia (or kinetic energy if you wish) and therefore requires more energy to stop.

now you mentioned your Ranger has studded tires... there's the rub. nothing beats studded tires. have you tried studs on the Civic?

igloomaster

thanks for the insight. maybe i should try studs on the civic - but right now it's an issue of not owning seperate rims.....i own a seperate set of rims for the Ranger that i got at a junk yard. i use those rims for the snow tires. i haven't had any luck in the junk yards finding Civic CX rims that are 14"....they went to the bigger rims recently. i guess they were all 13" in the past. i don't know if the older Civic 13" rim has the same bolt pattern or not. I'd use a narrower 13 if i were sure the rim would fit on my '99. Soon as I find rims that aren't a fortune (probably next season) all throw 4 studdies on the Civic.

garth

this may be an idiotic suggestion, but if there are a lot of punk kids in your area who do heavy modifications to their Civics (coffee can exhaust, decals, 18" rims worth more than the rest of the car, etc.) - you may be able to get a set of stock rims from someone who bought aftermarket alloys. just a thought. happy motoring.

igloomaster

i'm actually looking to upgrade my exhaust system to paint-can-sized pipes myself.....

Onward:
Is there anyone out there who is driving a Civic Hatchback with over 150k miles, and can still report excellent service? If so - share a trick or two that got you there (example: changing the oil much more frequently than the manual suggests, etc.).

colorich

A little late in the season, but here goes. 1988 Volvo Turbo was awful in snow w/o snow tires, first few winters ran 4 studded snows-got around OK at first, but; 1)noisy, 2)not nearly as good after first winter (I supose restudding is possible) 3)dry handling was like tip-toeing. Fall '94 tried Blizzaks, WOW...quiet, great in snow, nearly as good as studs on glare ice, Mrs. rich likes them so well she didn't want them off in the spring (summer tires don't ride as nice!) I got 5 winters (about 35K miles), was just at the end of the "soft" compound when I gashed a sidewall on a broken bottle. Thus fall 99 = 4 new Blizzak W-15's again. Meantime Mrs rich got 99 Odyssey last March and I inherited full time use of Volvo. This fall she wants snows for Oddy, no Blizzaks in 215-60HR16 (at that time, there are now) so I ordered Artic Alpins from Tirerack (on wheels). These are great tires, I believe they may be even better on ice and hardpack that Blizzaks. Ride and handling are almost exactly like Firestone Affinity All Seasons the van came with, except the Alpins are quieter at most speeds. There is a slight whine on perfectly smooth pavement at in town speeds--noticable because the arterial nearest our home was repaved last fall. It will be interesting to see how the Michelins hold up, and how there performance changes from winter to winter. For my money, with my family aboard, 4 premium snows is the only way to go, regardless of FWD/RWS/AWS/4WD.

igloomaster

i agree with you!

on my 1990 Civic, I wound up leaving my snows on year-round.....at that time Blizzaks weren't around, so it was Goodyear Ultra-Grip. I didn't have studs, so year-round was great. The ride was much more comfortable, especially in that little car. the spongy-ness of the compound absorbed shock much better that the previous regular all-seasons.

yes, you wear them down MUCH faster when you leave them on all year, but i look at it as a luxury i want to afford.

Alpins have been raved about, as well as Blizzaks, for there non-studded performance.

cptplt

I have always loved my Blizzaks but when I got a new Subaru Legacy my old snow tire wheels didn't fit and as the Artic Alpins had a rave review from various sources I got those instead. I don't know if its me or the new car or the tires but when I'm on packed snow I feel like I am going to float off the road. The car stays on the road fine and the car handles fine but its almost like that sensation you get crossing those bridges with those metal grates providing a single square millimeter of contact with your tires! Anyone else noticed this with the Alpins?