Are four wheel drive vehicles better because they're safer?

[Who]

DPV, here's a real world example. When I get to the end of my very urban street in the morning I have to turn left. It's a busy 4 lane street with non-stop rush hour traffic heading the opposite way into Toronto. There's a bridge less than 100 meters to the left. It's being rebuilt, so half the bridge is closed. That means that there is a traffic jam on the other side of the bridge and therefore practically no gaps in traffic. I have to squirt through that gap with the kids. There were many mornings this past winter that I had to do that starting off on slush or ice. Our street tends to get plowed after every other street. I really liked having the AWD for this. My previous van was a RWD Aerostar and it would have been hell this past winter, to even turn right and then start cutting over to loop around and go back the other way.

Anyway, if you have to squirt through a short gap in traffic, AWD helps. Personally, I'd rather that we all move around in 1000 pound or less rigs with a single rear driven wheel that top out at 50 kph max, but that's not gonna happen any time soon.

Normally, I'd have never bought an AWD vehicle. They cost more, have way more maintenance costs down the line, waste fuel and resources, and typically don't really let you go anywhere you wouldn't normally be able to go with 2wd. I had a week to replace a written off vehicle and with more time would have gone used. The Vibe and the Santa Fe ended up as options that fit fairly well, I'm very tall, and that could fit kids bikes (they don't fit in the Accord's trunk without wheel removal and there are no quick releases) or my bikes (65cm frame size) and had attractive pricing and financing.

I actually agreed to purchase a 2.7L FWD model of the Santa Fe, but over the course of the weekend read how the real world mileage wasn't that good (high revving 4A vs 5A) and that the timing belt was super expensive (I keep vehicles a long time) and that wouldn't be need on the 3.3L. We test drove the 3.3L FWD that Saturday and it was raining. Pulling away from a traffic light caused the traction control to engage because of how slippery the paint on the stop line was. I hated that hammering and also hated the FWD's push through turns. The mileage ratings on the FWD and AWD models were practically the same so I bit the bullet (a whoppingl $7 a week) and got the AWD. I did that without knowing that the bridge would be rebuilt just weeks later or that we'd have more snow accumulation than we have ever had. But I did know how drama-free AWD can be and opted for it, and that with my luck I'd get it and gas would go sky-rocketing upwards. It's $4.46 a gallon here now.

[cbergeron]

DPV - free rolling wheels will _always_ coast easier when there is no gear assembly connected to them. The grease, lubrication, etc add friction - even at high temperatures, believe it or not. If you've ever put grease between your fingers, you'll see that it can act as an adhesive (albeit a minor one).

If you couple that to a wheel assembly that isn't actively turning a wheel, it results in unnecessary friction (or reverse friction, I'd guess). The fluids, greases, gears, etc. that aren't actively helping the wheels move are hindering it merely by definition of being attached to the wheel system.

[diesel_john]

Ok, let me define safe as "idiot proof".

interesting stats trebuchet03

true 4wd (locked transfer, limit slip diff's) very dangerous except in a straight line.

true 4wd (unlocked transfer)(hubs locked) ok except on slick surfaces because the front wheels are dragging and the back wheels are pushing.

Awd accels faster but stops just as fast as everyone else.

Awd with studs good on ice.

[Who]

Originally Posted by diesel_john

Awd good except on ice, where you either have studs or you do not.

Studs aren’t legal here because they chew up the roads and replacing road surfaces prematurely wastes a lot of energy and tax dollars.

If you’re touching the gas pedal AWD helps. If you are touching the brakes it doesn’t, and that’s because we already have balanced braking on all 4 wheels. All 4 wheels is the key. AWD distributes the motive power more evenly so that the chances of any wheel losing traction is reduced.

[Silveredwings]

So I'm hearing that 4wd has a higher chance of getting into a ditch, balanced slightly with the utility of 4wd helping get you back out ... unless you're too inebriated.

[Who]

Traction control is nowhere nearly as good as all wheel drive. Y'all as EcoModders and EcoLurkers have to be slightly appalled when the brakes are squeezed just to help you get or keep going. Worse yet, when they ECU intercepts the default throttle mapping and it greatly reduces the effective throttle pressure. All this while you try and pull across a busy highway at an uncontrolled intersection in a thunderstorm with your kids behind you. All wheel drive (4 wheel drive is dead in all but pickups) just allows you to keep traction a while longer before resorting to the same braking and throttle manipulation. Big difference in my opinion - to the point where the ESC gets in the way for the most part in deep snow unless you lock out the torque split. AWD is superior here because you can even drive locked up at all drives. They aren't mechanically joined so they'll split, and besides, the ECU takes over above 25 KPH anyhow.

The most surprisingly near ideal handling / controlling / driving vehicle I've ever driven was the Honda Pilot. It's looks don't sit well with me. It drives like it should be as swoopy as the smoothest most aero rally car if that isn't an oxymoron. Instead it sends a very confusing message. It should be smooth like the civics. And have a 2.3 litre 6 speed manual option, but I'd want the AWD it has.

[DifferentPointofView]

All wheel drive (4 wheel drive is dead in all but pickups)

Then why don't Jeep guys like AWD?

[Who]

DPoV - okay (pickups and 2 out 6 models in the Jeep line-up) Better?

[IndyIan]

I have a 2003 chevy tracker/suzuki vitara(same truck). We bought it because it was the only new vehicle left that had a 4cyl engine and what I'll call real 4WD with a transfer case, 2wd high, 4wd high, and 4wd low range. We use all 3 options often especially in the winter.

The good parts about 4wd is that it works very very well in slippery conditions, occaisionally our driveway is sheer ice and we can maintain speed on the 10% slope. 4wd also acts like anti lock brakes, unless you lock up all four wheels its impossible to lock one wheel or even one axle.

The bad part about 4wd is that it usually raises the centre of gravity of the car and driveline losses. 4x4's usually have more ground clearance and the engine is mounted higher to get it above the front axle, add the extra axle turning plus the transfer case and being rear wheel drive results in alot more friction even when you're in 2wd. So the 120hp tracker gets 9L/100km on the highway. Not stellar but there are alot of people driving 4wd trucks that would love to get that mileage.

Thought I would chime in with my experiences.
Ian

[diesel_john]

Also if you have unlocking hubs, there is 2WD low which I like for backing wagons.

I though AWD had traction control built in.