welcome! makes no difference. all that does is change the pedal sensitivity. you'd be more well served by adding snow tyres.
In snow ECO mode will help a bit, making it slightly less likely to spin the tires (or engage traction control) due to the sluggish throttle response. Kinda like the old adage with traditional automatics, to start out with the selector in "2", locked in second gear. But other than that, yeah: look into snow tires if you haven't already. Also, somewhere between 8 and 12 inches, no matter what tires you have, you will get stuck, due the car's ground clearance. Sooner than later if the snow's wet. I know all this pretty much vicariously, we never seem to get snow here.... But I'm ready, lol.
At 8 inches is about the point where our Prius high-centers. There is so much snow the under-carriage is packing down that it supports the weight of the Prius, leaving very little weight on the tires. Assuming the roads are plowed, and that you have good studded tires then you should be fine. Pulling out onto the roadway you generally have to push through a levee of snow tossed up by the plows. We have found that PWR mode does have a remarkable difference in handling when your punching through piles of snow. The same as when your stopped at a traffic light, and wanting to turn. When you get the green and you have to punch through a series of piles of snow. With 3/4 accelerator pedal in ECO mode you will inch forward and turn but your turn will will be a very wide turn, slow and hesitant. Either taking up both lanes, or else directing you into the ditch. Whereas if you try to same in PWR mode and 3/4 accelerator pedal you can more easily punch through the piles of snow and you can now complete the turn in a single lane. Turning while punching through piles of snow is much better using PWR mode as compared to ECO mode. Yes it is only a re-mapping of the accelerator. However there are times when you need the front wheels spinning instead of hesitating so much. It does make a difference. Now when you go out onto ice, like each time you drive onto a frozen lake or river. PWR / ECO makes no difference that we can see.
okay, we have there mode votes now, no difference, eco is better, and power is better. hope that helps!
I would vote.... The Prius is NOT the best tool to plow through 8 inch's of snow regardless of what mode you apply. But if I had to? Or wanted to try? I think I'm voting ECO with this questionable logic applied. ECO does map the accelerator pedal to be less responsive. This is under normal conditions to allow you to maximize economical driving. I would suppose on snow or ice this safety net of less sensitivity as you move forward "may" be an asset. PLUS.... If you feel you need the power to blast through a section? Even in ECO mode depressing the pedal farther down WILL engage the same acceleration reaction as Power Mode, so that benefit is really NOT lost. ECO just gives you more room to play with the vehicles "subtle" responses. Therefore, I may be wrong but I would use ECO first.
With heavy wet snow that deep on the road to my dad's house, the only mode that will work is 'tow hook mode'. The tow hook is stored in the tool holder atop the spare tire. Install it at one of the bumper attach points. Attach one end of a logging chain to the tow hook. Attach other end of chain to a crawler tractor. (That old Caterpillar D3, obtained from a retired logger, is a good choice.) Drag to destination.
For snow and ice conditions, ECO would be better as most "loss of control" issues comes from over-correction. If you spin your tires, easing off the gas is better than totally letting off of it. Same with braking. Locked wheels are best remedied by easing off the brakes, not releasing them entirely. As far as "plowing" goes, I'd avoid it. Unless it's "fresh powder" or already compacted enough, that front bumper won't do too well if you hit a solid chunk of snow/ice.
I'll add a vote for makes no difference. The 3 different modes are just your preference for pedal sensitivity.
By the experience of the Long Island weather, the Prius has a better handling on snowed roads in ECO mode.
Although I haven't played with the settings myself, I can see no reason why the throttle response setting would affect snow driving performance. The traction control will limit the throttle regardless of what mode the Prius is in. You can floor the throttle and the Prius will only accelerate at the rate it has traction for. The easiest to control throttle mode would be the one that is linear, which in the Prius is "Normal" mode. Placing the vehicle in Eco mode only gives fine control of the first half of the throttle. As you can see in the graph below, after the halfway point, the throttle becomes more touchy as it ramps up towards the same endpoint as in power mode. This has been my main complaint about Eco mode since it makes efficient acceleration more difficult with a touchy response. Toyota should drop the throttle response shenanigans and only offer a liner response, and re-purpose the Eco button to be a mode selector for when the throttle is released entirely. It would be nice to have a mode where the car coasts when the throttle is released instead of activating the regen and slowing the vehicle. Some may wish to have a mode that applies maximum regen when releasing the throttle to facilitate 1 pedal driving.
Also the end of the graph. If I floor it, the car seems to behave differently in ECO as it does in PWR. I don't think that floored equals floored in all cases. In ECO if you were to 'jump on it', vehicle acceleration is slow and gentle. Which on ice is a good thing. The same goes for stopping. Slow and gentle when you push through a pile of snow, may get you stuck. Or if you are turning [which is the example I gave previously] your turn radius will be wider in ECO while pushing piles of snow. In PWR your turn radius will be tighter. Try it.
The ECO vs PWR has been discussed to death. Flooring it in either mode produces the same results. Bring a stop watch and make 3 runs in each mode to see for yourself. Slow and gentle in snow will prevent getting stuck much more than ramming through it. If you're going slow and the vehicle stops, usually you can simply reverse out. However, if you are using momentum when the car gets stuck, then you're in a real pickle as it's high-centered on a mound of snow. You will then have to dig 90% of the vehicle out since the low point on the Prius is the entire underside. Getting a truck stuck after using momentum is less problematic since the low point is usually a differential or axle, which is easier to dig out. I speak from the experience of having encountered unexpected snow in a Subaru Legacy, and trying to power through it. The next 5 hours were spent with me in a tee shirt and jeans digging out using my bare hands and a piece of plastic I found. No AAA service on this untraveled winter road with no cell coverage. Why would the turning radius be different depending on ECO or PWR mode? The car is FWD and has traction control, which will limit throttle regardless of which mode is being used.
I've never messed with the drive mode when in snow. So my experience in ECO mode has been surprisingly pleasant up to 6" deep snow. I suspect that 8" of heavy, unplowed snow would be a drastically worse experience.
Except in my Chevy it has nothing to do with throttle response, as at cold idle it will spin the rear tires in snow as soon as you take your foot off the brake. Putting the transmission in "2" prevents that by cutting the minimum torque approximately in half (very wide ratio between gears). I doubt the mode in the Prius makes much difference as the throttle response in "power" mode still feels somewhat sluggish compared to most cars I've driven, so it's very easy to avoid engaging traction control if there's any amount of traction available. This is probably by design, as pressing the accelerator 1/4 of the way down on the Prius means "1/4 of available torque", as opposed to "1/4 throttle opening", which at low RPM will provide well over 50% of peak torque.
