Here’s the latest reader question, along with my reply!
Gill asks: Do full size SUVs like the Chevy Suburban really need 4WD to handle well in the snow or is 2WD sufficient? My thinking is that the weight of the vehicle will be sufficient for traction but I don’t know for sure.
My reply: The problem with 2WD – with rear-wheel-drive – trucks and SUVs as regards traction (as opposed to handling) is that they are usually light in the rear; most of the weight of the drivetrain is over the front wheels. This reduces traction. (It’s also why FWD cars – which have the weight of the drivetrain over the drive wheels – are generally better in snow than RWD vehicles.)
Now add to the mix that all the engine’s power is flowing to just two rather than four wheels. If those two lose traction . . .
If you have 4WD (or AWD) you have multiplied your traction footprint, so to speak. The engine has four rather than two possible avenues to propel the vehicle forward. Also, truck-type 4WD systems usually have a two-speed transfer case and 4WD Low range gearing, which is a huge help in deep/heavy snow and (of course) off-road.
With that said, some general advice:
If you don’t have to deal with snow more than a few days out of the entire year, going with 2WD may be sensible in that in exchange for having to deal with occasional snow days, you will pay less for the vehicle and less for gas the rest of the of year. In my opinion, 4WD only makes sense if you live in an area subject to bad – and long – winters, where you’ll need 4WD to get around and not having that capability would be more than an occasional inconvenience.
You can improve the traction of a 2WD truck or SUV by weighting the rear end (bags of cement, whatever is handy) and shoeing the thing with snow tires. Also, if you’re shopping for such a vehicle, be sure to buy one that has a limited slip rear axle. A RWD vehicle – truck, SUV or car – without limited slip is like brushing your teeth but never flossing!
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I just purchased a 14 suburban which I thought was awd found out it was 2wd it have stabilitrack and traction control with the g80 diff do you think I’ll have a problem with getting stuck in the winter
Not at all. 4WD – with a transfer case and Low range gearing – is in my opinion oversold. It is great for plowing through deep mud, off-road and for dealing with heavy snow on unplowed roads. But how often do you have to deal with either? If you mostly have to deal with occasional snow on plowed and paved roads, AWD – with the right tires – will almost always see you through and without the expense of dragging around all the extra weight of that transfer case and peripheral gear!
What do you call a 2WD Suburban? Stuck!
You would THINK that a Suburban or full-sized van would not be too light in the rear….but the reality is: They are!! Sheet metal doesn’t weigh all that much- and no matter how you stack it, the rear is a good deal lighter than the front, where the motor and tranny, etc. are- and in a 2WD vehicle, it’s just essentially pushing that heavy dead weight in the front with one back wheel in low traction situations.
Which I guess is why it’s been my experience, that full-size vans are every bit as bad, if not worse, thatn 2WD pick-ups. My old E150- great vehicle- but on anything but perfectly level ground, be it just a frosting of snow, or soft dirt, or even wet grass…..that baby wasn’t going anywhere.
That van, which should have a lot more weight in the rear than a pick-up, had the poorest traction of any vehicle I’ve ever owned- and I always ran nice meaty all-terrain/snow tires in the rear. A 2WD Suburban/SUV would be the same. It’s not just about weight in rear of a RWD vehicle, but about weight distribution, and about having more than one tire that can get traction in a limited traction situation.
The fact that Suburbans/cans/P-U’s are heavy, makes it even worse; and makes 4×4 even more necessary.
2WD vs 4WD on a Suburban or similarly large/long SUV is an interesting question, and one that isn’t quite as easy to answer as I think you made it out to be, EP. it really boils down to your intended use case.
Most folks want such a long SUV for hauling and towing. Neither of these require 4WD and usually the 2WD version has a higher tow rating. On dry pavement, there’s little to no difference in performance. Even the mpg difference will be hard to notice, as the EPA ratings are usually within 1-2mpg for comparably equipped models with the only difference being 2WD vs 4WD being the big price difference.
In terms of longevity, having the fewer driveline parts of 2WD means less to go wrong and less to maintain.
As tallpine mentioned, SUVs are much more balanced in terms of weight than a pickup, but they’re still lighter in the back. It just doesn’t take as much to address that. Yet if you have a front wheel drive car or something else better suited for winter weather driving, then leave the Suburban parked on those days. How often that is will depend on where they live.
More significant is the fact that if you are pulling a large boat, pulling it up a wet boat ramp with wet rear tires can be challenging. This is where I tend to see 4WD used in long wheelbase vehicles, including heavy-duty pickups. It’s clamering up slippery ramps or other such surfaces, not blasting through mud pits. Most of the time these are not used off-road much, if at all.
Ultimately it breaks down to the price difference between 2WD and 4WD in terms of up front purchase (new or used) and long term maintenance.
Eric, Suburbans are NOT light on the rear end as pickups are. All that extra metal and glass add up.
We had a 2wd (4 speed) Suburban for years and that was when we were living in a snowy mountain town in Colorado, and we got around just fine through six months of winter. We have a 4wd Suburban now but I don’t even use the 4wd unless the snow is really deep or it is muddy. The only thing is that with the automatic instead of an old 4 speed, the low range is nice to have.
If I didn’t live out here in the Montana Outback, I wouldn’t own a 4wd at all. (we have three)