Snow traction

same thing /

BION

 

As in any vehicle in the snow, whatever setting will allow you to deliver less torque to the wheels and do it more controllably will be the win.

In the years I drove manuals, I would often begin in 2nd gear in snow rather than 1st, to ensure lower torque reached the wheels. A friend had an old Ford with an automatic where one of the settings prevented use of the low gear. That was handy too. Often automatics will not have such a setting, though. They'll have one to force use of the low gears, but not one to force non-use of the low gears.

In a Prius, the setting that gives you the most control in the low-torque range will be ECO. There are no differences between ECO, normal, and PWR modes at the no-pedal and full-pedal ends of the range, but they differ in how the response curve stretches between those endpoints. ECO gives you very good control over the low-power range and then gets steep to catch up near full pedal. PWR gives you a steeper low-pedal response and then flattens out.



As it is around the right time of year to repeat the PSA, when you are driving a Prius in snow, the aim is to look like one of these guys:

and not look like this guy:

All that ice-polishing will rarely be helpful toward getting where you want to go, and can end up getting you very decisively stuck. It doesn't even matter much whether you've got 2 or 4 polishing wheels, if that's the way you're going to use them.

 

Every October we shift to studded snow tires, and every April we shift back to summer tires. It is the law here.

If there is a lot of piled up slush on the pavement, it does help to be in PWR mode.

In ECO mode the vehicle is a lot more sluggish, and piles of slush will push you around. But in PWR mode the vehicles handling is more aggressive when driving in slush.

A good deal of our driving is on ice. Once the rivers, lakes and ponds freeze over everyone just drives directly across on the ice rather than driving around any body of water. On ice I see no difference.

At intersections where everyone must stop, it can be humorous to watch as when each driver hits the accelerator and tires start spinning, there is a pronounced delay before vehicles move. Rear Wheel drive is the worst, they will, all 100% of them will fishtail wildly. If a Read wheel drive vehicle is turning at an intersection they will everytime fishtail out so far as to cross into other lanes of traffic. Thank god for Frontwheel drive vehicles.

 

I-95 where it goes through our town is posted at 75MPH, nobody drives under 82mpg. Some on-ramps are short, so you need to go from stopped to 82 quickly. I always use PWR when getting onto the interstate.

If you stay in ECO you will never get up to speed within such a short on-ramp.

 

Because the upper and lower endpoints of all three response curves are the same, if you can get up to speed in PWR, you can do it in normal and in ECO by pushing the pedal far enough.

 

I have tested that theory many times, even to the extent of a passenger using a stopwatch.

It simply does not work that way IRL.

 

After replacement of "theory" with "documentation from manufacturer of how car was built", there could still be room for investigating why you might have seen what you say that you saw.

 

I have seen that theory posted many times on this forum.

And yet IRL, things are different.

I am okay with IRL.

In my observation what happens online is often its own special case far removed from IRL.

 

Curious if this is in the Gen4 Prime or a previous Gen?
Just wondering if Prime is different. ?...?...

 

Still, it's a little dishonest to keep calling it "theory" when it is from the car builder's manual explaining how they built the car. The diagram reposted in #3 is not some random PriusChatter's artistic creation.

 

I have had witnesses use a stopwatch in my 2011 Gen3.

When I have done it in my 2017 Prime, I can not tell any difference though, I have not gotten any witnesses to test it yet.

 

I entirely understand what the designers were attempting to do.

I have no doubt that the manual says such.

When you take all of that out into the Real World, you find that some things from the drawing board are in fact theory, when you attempt to apply them in the Real World.

The designers wanted the vehicle to handle is such a manner, I get it. However I also get that it dont.

Calling a fantasy something other than theory would be dishonest. Acting like your fantasy stands in reality would be dishonest.

Fantasy is fantasy and will remain a fantasy until such time that it is no longer fantasy.

Reality, on the other hand, is entirely different.

 

When I was getting on I-5 and I-90 on-ramps two days ago in severe weather, nobody had any chance of getting to those speeds that quickly in any mode, with any tires whatsoever. Rockets or cogged rails would have been required. Followed by the need to quickly slow to the prevailing traffic speed before rear ending the traffic ahead.

If people were driving 82+, it wasn't real snow and ice on the road.

 

Only folks riding sleds go over 70mph on the ice.

If I can not see pavement I generally keep it below 60mph.

Our township does not use salt. the plow truck scraps the snow/ice smooth level, so at least the potholes get filled in.

Other municipalities with much higher taxes, they use salt to get down to bare pavement.

 

More people need to know this and Toyota hasn't helped matters by how the different profiles are named.

So ForrestBeeKeeper, you think that when the pedal is to the metal in PWR mode, somehow the engine is more powerful than in ECO mode?

Directly from Toyota

 

There is a clearly discernable difference.

Jab the accelerator to the floor, as hard and as fast as you can. Hard to the floor.

The vehicle acceleration is different.

Maybe it is in the fraction of a second that it takes for the accelerator to reach the firewall. During that quarter-second the computer is thinking slow-sluggish.

Leave the printed manuals and design specs for a minute. Go out into your car and try this.

 

Sunday here, at the time I started out, only a few speedballs were even doing 45 on the Interstates. Several were in the ditch. On one special section, nobody was even above 35. I didn't see anyone hit 60 until about 70 miles from home and well beyond the pass. I waited a bit longer.

A couple later segments were equally nasty and slow, but fortunately much shorter.

Punching PWR would have led to a lot of ice polishing, as shown in the last video of post #3. Even with a Subaru.

 

With two manual cars in the household, we still do. On some of dad's old pickups, even 3 would work, but our cars are geared too tall to use that.

My last automatic, also a Ford, allowed the driver to select just 1 or 2, though not 3. 2 got me going on the glazed uphill ice in front of dad's main gate many times after having to stop to open it, even in conditions when setting the parking brake, the car would have to slide backwards several feet to find a less-glazed patch with enough grip to hold. Starting very gently, 2 could get the car moving even in conditions were my boots had difficulty keeping me standing.

I'm among the ECO believers.

 

Lots of electric cars in your town, apparently.