My wife has a 2017 Toyota Highlander with All Wheel Drive (AWD) while I have a 2019 Toyota Tacoma with 4-Wheel Drive (4WD). The Tacoma has both a 4WD high and low setting.
Is my wife’s AWD equivalent to my truck’s 4WD high setting? I drive both vehicles and they have identical tires (Bridgestone Blizzack non-studded show tires) and I feel safer in my truck in the winter than in my wife’s car, (which is strange since the backend of a truck is much lighter than the backend of an SUV). The truck is less likely to skid on snowy or icey roads than the Highlander (IMO).
Is there is a difference between AWD and 4WD high, and if there is a difference what is it?
Yes, AWD and 4WD are fundamentally different. It’s a big topic with lots of nuance, but for off-roading or very low traction situations, 4WD is almost always better than AWD.
Here’s a good writeup on the differences from Edmunds: 4WD vs AWD
4WD with locking differentials basically mechanically couples all four wheels together, so loss of traction on one will not cause the others to slip. AWD ‘intelligently’ decides which wheels should get power. In practice this often means that the vehicle is usually in 2 wheel drive mode (in part-time AWD systems like the Ford Escape and many other small SUVs), and the other wheels only engage if the system detects slippage in the drive wheels. Some AWD systems drive all four wheels all the time (like Subaru), but the system still determines how much power should go to each wheel depending on conditions.
The problem is that often you only get the back wheels in play when the front wheels have already lost traction. And if the front wheels start pulling again, the back wheels will stop helping. There is a large amount of variance on how it’s done between manufacturers.
AWD is good for dry roads and typical snowy/icy conditions on roads, as it can keep the vehicle from losing control. But it sucks compared to 4WD for ultimate traction in hardcore situations. 4WD, if the diffs are locked, is not good for dry pavement as the wheels will try to turn at different rates in corners, causing binding and damage.
There are many AWD and 4WD systems, and some differ quite a bit from others. As the Edmund’s site notes, increasing sophistication of both is starting to blur the lines between them.
‘Low Range’ is just a gear change, allowing for more torque at low engine RPM. Sort of the opposite of an overdrive. Low range is useful for hardcore off-roading when you need to crawl over obstacles that require a lot of torque but slow speeds. Driving through mud and deep snow, crawling over large rocks, pulling stumps, etc.
Part time 4WD (like your Tacoma) should never be used on dry pavement, since the front and rear axles are locked together and cannot turn at different speeds. Around a turn all four wheels are turning at different speeds and on dry pavement you can bind up or break something.
Full time AWD has either a viscous coupling or center differential to let the axles turn at different speeds and can be used on all road surfaces.
I’ve driven mainly Jeep Wranglers the last 20 years, but this time around I have a 2019 Jeep Cherokee. It’s 4WD and has the terrain select (which are sport, normal, sand, and snow). I’ve had to use snow mode a few times and it works great.
All that said, whether your wife’s car or yours is better on the road in snow and ice depends on the exact systems in use, the suspension, etc. Most AWD vehicles are build on essentially car chassis, while FWD vehicles are often still solid-axle, ladder frame vehicles. The former will drive better on roads, and respond better to things like potholes. A good AWD system will be part of the stability control system, and move power to wheels to keep the vehicle from rotating in a skid. So AWD CAN be better than 4WD on roads with modest snow and Ice, but you wouldn’t want to take one over the Rubicon trail.
One other factor - pickup trucks have a high center of gravity and suspension systems that aren’t the greatest for just driving down the road. And one of the most common fatality modes in trucks are rollover accidents when the vehicle loses control at speed. So without knowing more, I’d say that your vehicle is less likely to get stuck in snow or mud somewhere, but hers is less likely to kill you.
Are you saying that 4WD systems cannot be used as an ordinary car, but only in bad conditions? So why would any ordinary person (who has occasion to drive in snow, but mostly avoids it) possibly want one?
Some of us must drive in snow. I sure can’t avoid it. I have a 4Runner with locking rear dif,and the ability to turn on limited slip to all 4 wheels when thats a better choice. Also of course 4WD high and low.
In any case, for dry roads, you just put the vehicle in 2 wheel drive.
Oh, and for changeable coditions, say patchy ice, you can generaly leave it in 4WD high provide you aren’t making any sharp turns or city driving. I’ve been doing that with my trucks for 30 years and have had no problems.
It’s marketing first. The terms are sometimes used on some vehicles to mean what we generally consider the other system.
To me 4WD is meant to be driven in 2WD mode till you need 4WD and usually has a low range. AWD is made to be driven normally in AWD and usually does not have a low range.
We live at 11,200 feet. My Wife drives the new Subaru Ascent. Good car. Great for road trips. I’ve got a 2019 4Runner. A bit better to get through tough conditions.
Job schedules have almost always made it so I get home first, can fire up the plow truck and do the snow moving.
4bys and AWD’s we have had -
76 Chevy short bed (beat the absolute crap out of it. Owned it for 35 years)
84 Jeep CJ7 (stock axles sucked, and scared the shit out of my dog.)
~90 Suzuki Sidekick (good car for deep snow but basically a snare drum on wheels).
89 Nissan Pathfinder (beat it to death)
2002 Grand Jeep Cherokee. (Very good in deep snow, but you had best have a deeper wallet)
2006 Nissan Pathfinder (Good overall no real complaints)
2004 Ram 1500 short bed (doing well as a plow truck)
2017 Subaru Outback (Ok, not as large as my Wife wanted, and had a phantom electrical problem that know one was willing to track down [myself included])
2018 Subaru Ascent. (Good but more Subaru electrical problems)
2019 Toyota 4Runner (Good so far)
I had a Nissan 240sx when I first move to altitude. Fun car for a younger person. Thought that I could make it work if I put studded snows all the way around. All I have to say about that is HAHAHAHHAHAH.
And a Alis-Chalmers tractor that I finally worked to death. I have a 2016 Kubota that I can’t say enough good things about (don’t want to piss it off).
IMHO, AWD is fine and getting very good. Things to consider are - Is it tough enough to pull other cars out when you need too? Where are you going to winch from? And of course your typical AWD isn’t meant to be off road.
Also, if you are in real snow country, buy the best snow tires you can.
Every 4WD car/truck I have ever owned has a selector shift with (2WD-4H-4L) as options. You keep it in 2WD until you are driving on slick roads and then you shift it into 4H. 4L is only used for those very slow, climbing over stuff, getting out of a very bad spot scenarios.
I’ve always viewed the difference between the two as a transfer case that can be put in low or hi.
However, I feel someone should point out that many true 4WD systems these days have a part time selector exactly for things like commuting on snowy roads where pavement may be clear at times and snowy at others. Both of my last two Chevy trucks had this.
My late model Expedition will split the difference. It’s AWD, but I can limit it to RWD, but I can also software-lock it to 4WD. I’m unsure if the software is smart enough to not ruin anything if I try to lock it on dry asphalt, though.
My older model Expedition has automatic 4WD, so the 4WD will kick in as needed, which is kind of fun on icy roads, but also has the traditional “real” 4H and 4L, that last time I forgot how to get out of while in a different country on a long weekend outside of internet range.
Yes, my 20 year old Suburban has this. It has proper 4WD with a high and low range, but also an Auto-4WD mode. In Auto mode the front drive shaft is connected (unlike in 2WD mode), but there is a clutch that keeps the front axle from getting power. When the rear loses traction the clutch automatically closes so the front wheels get power. The owners manual says that Auto-4WD can be used in dry conditions and at any speed. I use it for driving on snowy and icy roads, so I don’t have to worry about moving from slick side streets to plowed and dry main roads.
We drove in 4WD conditions when we were younger and foolisher. When we married four decades ago, she had a decade-old ex-Forest Service long-bed stepside Chevy pickup with a manual stick and split differential, for low-range RWD. It extracted us from many dicey situations. Then we got one of the last Toyota FJ-65 Land Crushers, which let us access places unwisely. We kept that for a decade and sold it for half its retail price to a collector who flew from Puget Sound to grab it. Since then we had a 2008 Nissan Murano AWD that didn’t do well in mountain snow, and now a 2017 Kia Sorrento AWD with “lock” that’s plowed through foot-deep drifts. It’ll do for now.
We’ve been to Sorrento (near Naples) but not Murano (near Venice) yet. Maybe next year.
We’ve gone through a series of small (25-foot) RVs, the latest riding a Sprinter platform. The Thor coachwork regrettably sucks but the 3.0L turbo-diesel gets 17-20 mpg, so we haul an apartment around for the same cost as driving the Exploder or Murano. Mercedes released a 4WD Sprinter, so if we wanted to go RV adventuring, that would do the trick. But we’re less young and foolish now, and the next generation of vehicles will likely see autonomous EVs as mandatory. So a robo-electro-RV may be in our future. Okay, the AI can drive while we screw in the back. What’s not to like?
Less than a foot of snow should fall tonight. I’ll be able to drive the Sorrento to the dentist tomorrow. Lower molar extraction FTW! I’ll carefully go into locked AWD
Back in '79 my friend and I where driving my 1976 Chevy C10 truck from Colorado to Illinois. Got that familiar vibration that some of us know when a U-Joint goes out. It was the rear drive shaft.
Kansas. 9 pm, 1979.
Found a service station (they used to be service stations with full bays and lifts, not just gas and ‘groceries’). It was getting late, and they were about to close. The owner let me put the truck on a lift so I could easily remove the rear drive shaft that had the offending u-joint (never went anywhere with out my tool box. All I needed was two wrenches anyway). I then just locked it in 4x and drove the rest of the way in front wheel drive. Drove 1000 miles back that way too.
The bad news is that you can’t just borrow a lift in a gas station anymore. The good news is that you don’t really need to as cars and trucks can go 200 thousand miles without much maintenance.
