Snow in 2wd w/ No Chains?

AutoLSD only engages at slow speed (<3mph) I believe. The mode does disable VSC which is nice and it is definitely better than TRAC for getting unstuck in snow.

https://www.tacomaworld.com/threads/3rd-gen-traction-control-modes-explained.530695/
https://www.tacomaworld.com/threads/traccontrol-or-lsd-in-4wd.646499/page-3#post-22474647

With my 2016 SR5 I got stuck in my buddy's yard in 4wd. My front wheels were in deep crusty snow, but the rear tires were still on the concrete driveway which was dusted with snow. He was about to get his F150 4x4 to pull me out when I switched to 2wd plus AutoLSD and got myself out under my own power. Now I have a rear locker and ATRAC, so the only time I use AutoLSD is when parallel parked on a street with ice near the curb and dry pavement further out. It's easier than shifting into and then immediately out of 4wd and I figure it is easier on the drivetrain.

 

Thanks for clarifying + it's nice to know that the Auto LSD got you unstuck in 2WD!

 

Same channel shows RWD on snow tires is worse than 4x4 with street tires with pickup trucks. This is a lot closer to OP's situation:



FWD Mazda with Blizzaks vs Jeep with Duellers in RWD and 4x4:

 

I watched that video and that look like compacted snow. As with the other guy from Minnesota my experience has been those trucks would get stuck just as fast as any other truck. We must have fluffier snow up here. When we have a good amount of snow you are basically limited to snowmobiles and atvs with tracks. Even then you can easily get stuck. Some guys do run some trucks with tracks....but tracks are expensive to buy and maintain.

 

https://www.youtube.com/watch?v=nMHgFdianrk

 

Everything in that first video rings true for me. It's basically a "DUH!".

It would be nice if he had tossed a fwd car into the mix to show how it is better than a 2wd pickup but not as good as a 4wd pickup.

I do think AWD is even a bit better for winter road driving. Some slip between the front and rear axles helps control the vehicle in corners and the ability to switch between snow and dry pavement without disengaging 4wd is key. I had a 2001 Subaru Forester and it was a riot to drive in the sniow (as long as it didn't get too deep).

My 2020 OR with the stock all-terrains almost has too much traction in 4wd to have fun drifting. I tend to put it in 2wd with TRAC/VSC disabled when I wanted to have fun on the road or in a parking lot. This was not true of the 2016 SR5 with all-seasons.

EDIT: In the 2nd video, although I would expect the snow tires to be better than the all-seasons, it's not an apples-to-apples comparison because the Mazda is fwd and the jeep is rwd. Fwd is better than rwd in snow.

 

This is why i said summer/street tires. I didn't say all-season, considering you can get snowflake rated all seasons. Makes sense though, since the truck has no weight in the back and getting significantly less grip than a fwd car. If they weighed down the back I bet it would perform a lot better or closer to the 4x4 with all seasons.

 

Instead of expending all that effort towing those guys, maybe he should have installed a plow and made a road for them. lol

 

By North American standards, General HTS as the name implies is actually a highway tire like the Toyota OEM Bridgestone HT and Dunlop AT20. They are all "all-season" as marketed here (not to be confused with "all-weather" tires with the 3-peak snowflake symbol). Actual "summer" tires like Pirelli PZero aren't widely available in pickup truck sizes unless you go with funny large rim diameters.

As I noted in another thread, adding weight in the back has its pitfalls as well - about 800 lbs is needed just to bring the truck to 50/50 weight distribution, then those 800 lbs would need additional traction to accelerate and stop. The friction coefficient mu for tires isn't a constant number, typically digressive (grip doesn't increase proportionally to load).

 

I can't really dispute this with any true science but it has been my experience that weight in the bed makes for a big improvement. The more the better. I used to throw 100's of pounds of rocks, logs, and whatever I could find in the back of my 2wd 1981 Datsun pickup. It's also evident when you watch heavy duty trucks making their way through snow seemingly effortlessly compared to the lightweight cars and trucks surrounding them. I've generally guessed that this is due to friction effects caused by the compression of the snow.

One case in particular happened to me in Oct during a snow storm. I was going up one of the steeper, taller hills in the Twin Cities. I became stuck behind a traffic jam caused by a bunch of FWD cars that couldn't make it up the hill. While I was waiting, a heavy duty RWD box truck with dualies passed by me. He was having an easier time than the FWD cars.

Other disadvantages of weight are decreased ground clearance, decreased acceleration, decreased fuel economy, and decreased room in the bed for other things.

 

My experience with rental 3rd gen Hyundai Sante Fe and 2nd gen Jeep Compass in the snow was locking the center diff gave more predictable handling, at least in the streets. On a closed course (where you know the layout and surface condition ahead of time) things may be different. My 3rd gen Subaru Impreza handles predictably in the snow dispite an open center diff - it may be a benefit of the symmetrically-biased AWD system.

The 2nd video shows FWD with snow tires gets better traction than RWD with all-seasons (as we all expect). It then shows 4x4 with all-seasons gets better traction than FWD with snow tires.

 

I might have missed it, but I didn't hear them call out the fact that the Mazda was FWD and the Jeep was RWD. I only heard them mention all-season tires vs winter tires and 2wd vs 4wd. A better experiment would have been 2 identical jeeps with different tires similar to the first video. That or the Mazda and the Jeep with the same tire type.

It also struck me that the two drivers didn't have the same skill level as far as driving in the snow. The first guy was really heavy on the gas like he was deliberately trying to dig down to the ice and roast the tires.

One final note, the traction control on that Jeep seemed like crap. I'm guessing our TRAC and especially our AutoLSD would have done better, but it's hard to be sure. he may have simply been sitting on more ice (or had hotter tires) when he tested the traction control.

 

Could you disconnect the rear drive shaft from the transfer case? then they could have one driver do 3 tests in one vehicle.... RWD, 4x4, and FWD

then repeat the full matrix with different tires

although that's a long day for me to just keep buying snow tires anyway haha

 

Actually the shovel comes in handy when you've floated the truck on top of the snow 'cuz it's packed under the skid plates, frame and lower control arms. Been in many a predicament with my '06 TRD OR AC plowing, got enough snow under the chassis which took a lot of weight off the tires. The only way out was to shovel the snow out from under the truck to get more weight back onto the tires.

Nothing more aggravating than 4WD + REAL snow tires w/ studs + diff lock and not being able to move.