From what I've been able to find that only works on 09' and older cars. I've figured out how to disable the awd system but not lock it into awd all the time on my 2013.

 

Snow mode just reduces/slows down the pedal input at low speeds. Stops you from goosing it from a stop when you're on ice... Kind of like a crawl gear? This way, the rears will lose traction under lower power conditions, and when AWD engages in the front, the torque will be much lower, reducing the chance of slip.

As for the AWD system. Afaik, it splits power 20% front / 80% rear when the rear wheels slip, otherwise the G37 is RWD under grip situations.
I actually really like this. Keeps the drive very lively, but if you oversteer, the fronts save you. Tested on the track multiple times, and saved me from embarrassing spin-outs.

Generally AWD doesn't mean you have grip when all 4 wheels are loose. Rather you're able to transfer power to any of the 4 wheels when they do grip up.
In a 4-wheel loss of traction situation, the G is in 20/80 mode, but TC will cut power until grip is detected. (I.e. the AWD seems like its not working). Then you'll get some power up front to try and pull you out of the slide. Fwiw, 99% of drivers (including me) dont have the driving skills to power out of the slide in a controleld way.

Careful driving on the stock all-seasons in the bitter North-East Ice has presented me no problems on multiple ski trips through Maine. Though I'll be getting winters for that extra peace of mind.

 

Get winter tires! Nokian are the best, Blizzak are very good, Michelin makes a good winter tire... DON'T use summer performance tires on snow! And All-Season tires will be sort of OK, but NOT great in snow. Here's a winter tire shootout => https://www.caranddriver.com/feature...es-for-winter/ it's kind of dated. The latest version of Blizzak are better than the version they tested, but Nokian is still the best. Nokain (from Finland) invented the snow tire. They know their stuff.

I live in Chicago and here they do not plow or clear snow from the alleys. My garage is on an alley. Last winter we had one snow event that dumped 10 inches of the white stuff on us overnight, and with my Michelin Premier A/S tires and AWD I had ABSOLUTELY no problem in the alley. We are not talking about performance here but about not getting stuck . (By the way, those Michelin Premiers were the **BEST** tires I ever had in rain. Consumer Reports tested them and found they had identical wet and dry stopping distance, the only tire ever to do that in a test.)

I have Blizzaks on now for the 2019-2020 winter, but last year I did not put them on, just to see how the A/S tires did in the alley. They were OK. But a 10 inch snowfall is not really considered REAL SNOW around here, and I think with deeper snow the Blizzaks are much better. Winter tires are a little harsher, noiser however. But I'll take the noise if I NEVER EVER get stuck.

By the way, the SNOW button does two things:Subaru's AWD is good, but they are not much fun to drive- especially now that most Subes have CVTs. Audi's system is good, except the Audi I had spent more time in the shop than on the road. It was the most troublesome car I ever owned. Expensive, and built to stay that way. I'm sure their Quattro system got great traction on the repair shop floor.