Whats so bad about all wheel drive?

Miscellaneous and Personal Stuff I Must Share
21

I’m kind of in the same boat, but the reliable snow removal isn’t instant. I love having my 4x4 SUV for those days that I have to make a 28 km trek home from work in a blizzard.

Knock on wood, the Mustang’s actually been pretty good in the snow and on the ice, despite having summer-only tires (that I can’t change, as the car belongs to my employer). It makes me nervous, though. I was doing some winter training with my wife, and she got stuck, and I was able to just push the rear end sideways onto a non-slick spot! On the other hand, that “winter training” involved making doughnuts, which inexplicably I was unable to produce in this car!

22

I wholeheartedly agree. Regardless of how fancy, or sophisticated, your suspension and traction system is, your tires are the only part of the vehicle that are in actual contact with the road. If you’ve chosen the wrong tires, it’s goodbye road, hello ditch.

23

TLDR: In all, 4WD & AWD have not cost me zero to own, but they’ve not cost me much. This is over about 500K vehicle-miles from several manufacturers over a 20ish year span of model years. So a decent sample.

Long version:

My last car was AWD.

I bought it used with 30K miles and drove it to 185K miles. In that time the front end half-shafts needed to be replaced once due to failed CV boots which eventually trashed the CV joints. The boots had failed again and the joints were wearing, but still fully usable, when I traded in the car.

Those components don’t exist on the RWD version of the car. Other than that one repair, AWD cost me nothing in reliability over 11 years and 155K miles. In all, it was a small expense on a per mile basis. And I never got stuck despite living in snow and especially ice country at the time.

Living where I do now I have no need of AWD and my current car doesn’t have it.

My wife’s current car is part-time 4WD. She got it with about 20K miles on the clock and it’s now at 110K miles. It needed a front transfer case overhaul and wheel hubs once when it was fairly young. Which was caused by an auto-locking hub that locked up for the heck of it. That was not under warrantee and was real costly on a per-mile-of-4WD-use basis. But she never got stuck.

Living where we do now I expect to put zero more 4WD miles on her car and its replacement will not be AWD.

Our three previous vehicles were part-time 4WD trucks. This is going back to the 1983-ish model year. One of them had the front drive shaft u-joint fail at about 120K miles. Despite not being used in 4WD much. That was surprising, but the part in 1990 cost about $15 and I didn’t even need to jack it up to install it.

24

Here’s the cost for maintaining cars by model. It has some correlation to reliability (e.g. BMW and Toyota) but in some cases it doesn’t (Mitsubishi). Subaru is a reliable brand that is also ranked rather low in cost, and all their cars are AWD except the BRZ (which is really a Toyota).

AWD helps you from getting stuck in snow, but is less effective than snow tires to avoid skidding. The disadvantage of the tires is cost and storage requirements.

One additional difference in 4WD vs AWD is that the former usually has 4 high and 4 low settings. You can lock an automatic AWD into 1st or low gear but I don’t think that’s quite the same.

25

On a Tesla, AWD gives better “economy”. The reason is that it has front and rear motors that are optimized for low and high speeds. Under normal, high-traction conditions it uses just one motor (the one optimal for that speed). When a motor is off it has no effect on vehicle drag, and there’s also no extra transfer case or anything. RWD cars have just one motor, so it can only be optimized for one speed.

26

The gas penalty of 1 MPG is minimal. It’d be a $342 difference* for me in gas costs over 20 years if I did not have AWD / 4WD, over the last 20 years and 300,000 miles in my Honda and Jeep. That’s an annual savings of about $17.

My cars have been reliable, and the AWD / 4WD systems were not a substantial repair or maintenance cost. No repairs to date — 225,000 miles on a 2001 Honda CR-V (AWD with 5-MT tranny), and 80,000 miles on a 2016 Jeep Grand Cherokee diesel (4WD).

  • — if AWD / 4WD penalizes you 1 MPG, then 300,000 miles ÷ 20 MPG = 15,000 gallons. If I got 21 MPG instead, it’d be 14,286 gallons. The △ = 114 gallons. At $3 / gallon, that’s a $342 savings.
27

I had an AWD 2002 Hyundai Santa Fe.
After 160,000 miles or so, the CV joints started to click, so I bought replacement axles, and went to install them myself.
When I pulled the first one out, I expected to have gear lube come pouring out.
But, no. Not a drop. Somewhere in the previous 14 years, all the lubricant leaked out. I replaced the axles, filled up the transfer case, and drove it for another year or so before I finally traded it in ($300- woo hoo!).

28

The gas penalties can vary on AWD systems from model to model. Smaller cars like Subarus with 4-cyl engines get pretty good fuel economy…larger V-6 or V-8 model SUV’s with AWD get anywhere from 2-6 MPG less than their FWD counterparts.

As noted, 4WD is a totally different animal, and is under normal driving circumstances a RWD vehicle until 4WD is engaged.

Today we now also have AWD vehicles like the newer GMC Acadia, that are able to disengage the rear wheels from the AWD system and revert to front wheel drive to save on fuel. We live in interesting times.
ETA: although I am having trouble thinking of an AWD V-8 powered SUV…most V-8 SUV’s are things like a CHevy Suburban that are trucks underneath the body and are actually 4WD, not AWD.

29

We have an AWD Forester and we still got stuck on a patch of snowy ice the other day. Took me about 20 minutes to maneuver out of there.

30

Ice is altogether another matter. IMO, no matter what kind of drivetrain or tires you have, ice cancels out all the advantages and hands you a pair of skates and dares you to travel further.

31

Unless the tires are studded, they can be shaved down to match the old tires. https://blog.tirerack.com/blog/docs-advice-on-tires/needing-to-replace-just-one-tire-on-your-subaru-youll-need-a-shave-as-well

32

I have a hard time believing this has any real effect. A 25" tire spins at 1008 rpm @ 75 mph. Worn from 10/32" tread to 4/32" (any less and you’d want to replace it anyway), it increases to 1024 rpm, for a difference of 16 rpm. It doesn’t seem too likely that a revolution every 4 seconds could cause any damage. And the front-rear difference is half of that (every 8 seconds).

33

A drivetrain that permits locking all of (a) left front and right front, (b) left rear and right rear, and (c) front and back, will not get stuck on an icy patch as easily as one that does not have full lockability, for the nature of a non-locking differential is to provide power to the slipping tire at the expense of providing power to the non-slipping tire, meaning that the more gas you give 'er, the more the slipping tire will slip while the non-slipping tire sits there picking its nose waiting to be given some power.

What’s out there that has front locking differentials, rear locking differentials and central (front to back) locking transfer case? Not much. For example, the Jeep Wrangler Rubicon does, but the other Jeep Wrangler models usually do not. The down side of having front and back differentials locked up is that it impedes turning. For example, if you are turning to the left, your right tire must travel more distance than your left tire, so having them both rotate at the same rate is not optimal. If you are on ice or snow or sand, the tire slippage wil negate this problem, but if you are making tight turns on summer pavement or warm rock, forcing wheels travelling different distances to rotate at the same speed will be hard on the differentials. Think of fully locking four wheel drive as the Tank Girl of the automobile world. Ain’t nothin’ gonna stop her, but she’s rough around the edges.

In contrast to lockers, all-wheel drive vehicles use different types of computer-magic spells to control power to all four wheels. Some all-wheel drive systems are better than others. Subaru’s system is the one that will always get power to the wheel that needs it, primarily due to it’s all-wheel drive system being symmetrical rather than asymetrical.

Both the Jeep Wrangler Rubicon and Subaru all-wheel drive can get the vehicle moving when only one wheel has traction. Once you get going, inertia is a bitch for winter driving, so remember that regardless of drive-train and with identical tires, it will take longe for the heavier Rubicon to stop than the lighter Outback, and it will be more difficult to control a skidding Rubicon than and lighter Outback. Take your pick between a gas guzzing holy-shit-le-merde unstoppable tank, or a nimble, more fuel efficient car that can handle ice but will end up floating earlier with no wheels making contact when the snow gets deep, if it hasn’t already lost its guts all over the trail due to lack of ground clearance. For trail and off-road driving in crappy winter conditions, go with the Jeep Wrangler Rubicon. For on-road or dirt road driving in crappy winter conditions, go with the Subaru Outback.

Note that although locking diffs or all-wheel drive make all the difference in getting going on ice, neither makes much if any difference in controlling the vehicle’s lateral movement, for control of the power going to a wheel is meaningless unless the tire can grip the road. That’s where having the right tire for the particular conditions comes in.

A soft and siped/groved ice tire (e.g. Nokian Hakkapeliitta or Bridgestone Blizzak) will provide grip on ice that a harder and/or less siped/grooved tire will provide https://www.tirerack.com/tires/tests/videoDisplay.jsp?ttid=116. Bonus points if your jurisdiction will permit studded winter tires like the Zamboni uses while the Habs and Leafs are taking a break.

Tire grip makes a great difference both for getting going and also for controlling the vehicle’s lateral movement. Better control of the vehicle’s lateral movement is why rear wheel drive vehicles should be fitted with snow tires on all four wheels rather than just the rear wheels.

Remember that even although winter tires will give you a great deal more lateral control (turning and skidding) on ice than summer tires, that extra control will not be as great as the improvement in non-lateral control (straight-line accelerating and breaking), so just because you can start and stop better with winter tires does not mean that you will be able to corner equally as well. You won’t. Don’t let the extra grip of winter tires fool you into believing that they will corner the way summer tires corner in summer, for although winter tires are remarkable, they are not God.

The long and short of it is that for ice driving, either locking differentials or all-wheel drive give you usable power even when up to three of the wheels are not getting traction, and winter/ice tires give you far more traction. The right combination of powertrain and tires can take the stress out of winter driving. Yes, you must take greater care when winter driving, but with due deference to the conditions, it has neither the white-knucle nonsense or frequent stucks suffered by folks who drive on snow or ice with two wheel drive and/or summer tires.

34

Great points, Muffin, although my (thankfully limited) experiences with ice aren’t so much getting started or stopping, it’s more along the lines of “Oh shit, I’m going 40 and now I have lost control of my car due to ice”.

35

My sister (southern Ontario) got rid of her Mustang for a Subaru Outback because the joy of a muscle car in the summer was stressful for her in winter storms. She wanted something like my Jeep Wrangler Rubicon for winters (I’m in north-western Ontario where winters are real), but with better road handling. She’s been chuffed about her Outback’s performance in winter storms. In a perfect world, we’d be like you, each with a Mustang and a 4x4 SUV. (Do I sound envious? Nah. Not really. Well . . . perhaps just a bit ;).)

36

Not all Mustangs are muscle cars, although that has changed in recent years. Late model Mustangs are ALL in excess of 300 horsepower (turbo four, 6-cyl and the V-8 GT and the even more insane GT-350). However, the most important change for the Mustang occurred very recently with the (finally) shift from a live rear axle to a true independent rear suspension.

This probably doesn’t help matters in the snow as they are all still RWD cars (I’ve owned a couple…super fun to drive on warm, dry pavement…snow and rain…not so much) but if you can toss your husband or wife into the trunk along with some bags of sand, you can probably get her nudged along.

37

Perhaps either one or both of the Electronic Stability Control and Traction Control functions of Ford’s AdvanceTrac were still in the default ON settings. If your Mustang is a late model, to turn off both the electronic stability control and the traction control, do not apply the throttle/gas, and while applying and holding the breaks, and press hold the AdvanceTrac button for five seconds. That let’s loose the dogs of war. Just pressing the button once will only turn off the traction control. Just pressing the button twice (sport mode) will only reduce the traction control and reduce the electronic stability control. For donughts, you need both fully turned off.

That, or at the start of your first donught you sideswiped your instructor, who’s body under your rocker impeded the donught.

38

I had the opposite, a 67 Toronado: 425 motor and front wheel drive transmission. There’s understeer, and then there’s UNDERSTEER. It could no more do a donught than a sumo could limbo. But for winter driving, it was the shiznit – just point the wheels where you wanted to go, and it would go three wihout any adieu. Spinning out was not in the equation.

39

The silver lining, here, is that you can feel like a rally car driver when driving on unplowed roads. At the breakneck speed of 20 mph, taking corners at a whopping 5-10 mph.

While you can go a bit overboard, I’d actually recommend doing this a little bit when the streets are empty and unplowed after a snow storm. That will teach you how the car handles at the margins, and how to recover when you lose traction.

40

To the OP - I suspect your cousin may be a bit skittish about car repairs, and or driving in snow. She really should not be too concerned about AWD costs, and buy what’s needed for the climate and driving needs. Some folks just don’t have to go out when the weather is bad, so that’s a consideration too.

As has been said, good tires make a big difference, but not all the difference when dealing with snow and ice. I get a ridiculous amount of snow where I live so AWD/4WD, snow tires and good ground clearance is a requirement.

And still sometimes that is not enough. My plow truck is - 4WD chained up on all 4 wheels with a 10,000 lb winch on the back. When that gets stuck, prepare for a really, really bad day.