When's the last time you drove through more than 6 inches of snow?
~Skip this entire post* if you didn't have to think hard on when that was
Four-wheel drive is only going to get you in trouble 97% of the time. I know arguments can be made for situations that only a 4x4 could traverse. But unless you live way off in the country or in the mountains, your likelihood of being in that situation is pretty darn low. I can only think of 3 situations in my 10 years of driving that I needed a truck for, and two of those were easily avoidable but kinda fun.
The rest of those situations that tempt you to kick it into four-wheel drive are in the slippery category, and 4wd will only get you INTO trouble in those situations. There was a REASON that your rear tires slipped every time you blipped the throttle and that reason is still going to be there when you try to brake.
Your trucks weight and higher center of gravity are also going to cause you problems. To maneuver successfully in slippery conditions, your tires greatly reduced grip on the road needs to overcome your momentum. Weight is going to increase the momentum more than it increases grip. A higher center of gravity unevenly distributes that weight during maneuvering, which both reduces the grip of some of your tires and during rebound, can literally 'throw your weight around' suddenly adding momentum in directions you weren't expecting and your grip can't cope with.
I have driven four vehicles extensively in Michigan and Wisconsin winters, a minivan, a 4x4 pickup truck, a box van with duelies, and a Honda civic. The ONLY one of those I haven't ever had an accident or a close call with is the Honda civic. I've driven in snow high enough to hear the scraping on the undercarriage, cornered faster than I could believe on white ice, and gotten caught in a surprise blizzard in northern Michigan; all without mishap. (The blizzard cost me 20 minutes when I pulled into a gas station and waited for a snowplow to go my way)
IMHO, the only two reasons to be in a big 4x4 truck on slippery roads are 1: you already expect to run off the road into a snowdrift and heroically drive yourself out of it. 2: you value your own life so much more than other peoples that you drive a vehicle that is LESS maneuverable but increases your safety at the cost of others on the road.
*maybe 'rant' would be more truthfull than 'post' in this case.
Joined: Aug 02, 2006
Posts: 705
Location: McLean, VA, USA
Posted:
Thu Nov 30, 2006 8:25 pm
moved to the front page
And, btw, trucks' safety is also questionable. Truck itself is going to be intact in most of cases, but I wouldn't say the same about people inside this truck...
By the morning after I wrote that post, there was 7 inches of heavy snow being blown around by blizzard winds. None of the plows were out yet and I had to get to work.
I did realize that I made one point badly. If you have a truck, 4wd will help you drive safely IF you don't get overconfident. I'd choose a 4wd truck just like I'd choose a Awd car for slippery conditions.
Joined: Aug 02, 2006
Posts: 705
Location: McLean, VA, USA
Posted:
Fri Dec 01, 2006 4:21 pm
Man, you are turning on a dime!
Can you tell a bit more on this, I mean what exactly are safety features you found in AWD, and how did you found about them
And on a side note - we have 74F on the termometer here
Its honestly just easier to make the vehicle go the direction you want it to when you have four wheels doing the going. ...and THAT is why its so dangerous. if you don't have to think about going, you probably won't think about stopping.
The thing is though, if you're quick and paying attention, you can get out of the way of an accident that you wouldn't have been able to maneuver around with only two drive wheels, ESPECIALLY a Rwd truck.
oh.. and I was only saying I'd choose 4wd or Awd over 2wd, NOT that I'd choose a truck over a car.
Heck, my cargo van almost went sideways into the curb today when I tried to make a left turn at like 2mph! It slid across two lanes in slow motion and there was nothing I could do about it except wave to the stopped traffic
Joined: Aug 02, 2006
Posts: 705
Location: McLean, VA, USA
Posted:
Sat Dec 02, 2006 7:23 pm
Yeah, now I understand your point.
I would just think AWD would probably start sliding at 2.5 or 3 mph... Does not really make a whole lot of difference in this particular situation....
Spikes would make a difference, but I believe they are illegal in US...
4 wheel drive in snowy condition is surely not necessary because when power goes to the back wheels it tends to slip more and hence makes difficult to control in case of heavy trucks
Its honestly just easier to make the vehicle go the direction you want it to when you have four wheels doing the going. ...and THAT is why its so dangerous. if you don't have to think about going, you probably won't think about stopping.
The thing is though, if you're quick and paying attention, you can get out of the way of an accident that you wouldn't have been able to maneuver around with only two drive wheels, ESPECIALLY a Rwd truck.
oh.. and I was only saying I'd choose 4wd or Awd over 2wd, NOT that I'd choose a truck over a car.
Heck, my cargo van almost went sideways into the curb today when I tried to make a left turn at like 2mph! It slid across two lanes in slow motion and there was nothing I could do about it except wave to the stopped traffic
i don't think that are better in winter. plz don'd do this. it's dangerous for you.
*link snipped*
The advantages of all-wheel drive become more pronounced (as to overweigh it's disadvantages) as the conditions become more slippery. I do appreciate the benefit of all-wheel drive on snow and ice, and likely on muddy surfaces and to a lesser degree on gravel as well. In those conditions, rear wheel drive is going to be the least preferable drive.
All-wheel drive does not change the amount of grip, it allows to utilize it more safely for acceleration. I.e. it would be possible to accelerate further without lost of traction, and when the car slides due to excessive power it will do so more predictably. However, slides can also occur due to other reasons, like weight transfers, speed coming into the corner and braking. In these conditions, the drivetrain has little to no effect.
The effect of the car's weight is much more pronounced than that of the drivetrain and it carries various effects. While it is true that a heavier car will have a larger mass which in turn will magnify the effect of the lateral force on the car (based on the formula mv²/r), but don't forget the constant effect of the downward acceleration vector formed by the earth's force of gravity (based on the formula mgμ). According to this it would seem that the negative and positive effects cancel each other out.
In action, however, more vertical load reduces the tires' coefficient of friction, so overall there is a slight lost of grip. Heavier cars, or loaded cars, make up for this negative effect by using sturdier tires and higher inflation pressures, which will increase lateral grip slightly overall, especially on bumpy surfaces. However, trucks are not only heavier, but also have a higher center of gravity (on which the aformentioned vectors are applied) and also stiffer springs, so overall a truck will grip less than a sedan, and will take longer to stop in particular.
The effect of weight on drivability is much more profound. A heavier vehicle takes longer to react to inputs of steering, braking and acceleration. This makes it feel more predictable and progressive, but it might not react to our inputs in time when we need to veer or stop. This effect is magnified by the truck's height center of gravity, but somewhat balanced by the utilization of stiffer springs. A lighter car will react more quickly to our inputs, but it might make it feel too sharp to handle.
Once you do overcome a car's grip levels and make it slide, the lighter car will again react more quickly and transition into a state of sliding much more rapidly, even though the slide itself is also likely to be more "controled." A heavier car will go into a slide more progressively, but might be harder to regain control of. Overall, the average driver is better off in a standard road car than in a truck.
By the morning after I wrote that post, there was 7 inches of heavy snow being blown around by blizzard winds. None of the plows were out yet and I had to get to work.
I did realize that I made one point badly. If you have a truck, 4wd will help you drive safely IF you don't get overconfident. I'd choose a 4wd truck just like I'd choose a Awd car for slippery conditions.
Good séance of humour, I will try what you have mentioned here. I hope it will not create problem to me.
This comes as great news to the trucking industry as well as to the entire motoring public! The improvements made to the trucking industry are a clear testament to the commitment to safety that is made by the industry.
Your trucks weight and higher center of gravity are also going to cause you problems. To maneuver successfully in slippery conditions, your tires greatly reduced grip on the road needs to overcome your momentum. Weight is going to increase the momentum more than it increases grip.
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