Braking downhill on an icy road

Some good answers in this thread, but I think what it all boils down to is that there really is no valid reason to shift to Neutral while in motion, and also few situations where most drivers would even need the B mode.

Generally, just use the brake pedal and let the computers do their thing.

I believe the main reason traditional driving technique recommended engine braking (B mode in the case of Prius) was for long downhills so as to not overheat the brake and reduce braking efficiency (and pad life). While the concept is still valid in the Prius, it is not nearly as prominent since generally a downhill coast/brake will run in regen mode, which doesn't use the friction pads anyway, *unless* - as I understand it - the battery is completely full and it resorts to friction brakes as a result to bleed off the excess energy. But again, this would only be on a very big downhill, that *most* people would not encounter on a regular basis.

Driving in snowy/icy conditions is the other situation where B mode may come in handy, but again you can also get by just as well using D and driving responsibly. Slightly OT... with full-time traction control, snow tires are definitely a must on this car, compared to the factory Goodyear Integrities (do the 2010's still come with these?).

Which brings me back to my original point, that there are even few situations where B mode is really "needed"... Just use the brake pedal.

 

Actually it'll do the opposite - if the rear end is braking away then they have lost traction and in FWD this is usually down to the rears locking under braking. Reducing the braking gets them spinnging again and they are more likely to get back into line.

Now if you were RWD then yes, it might try to use the brakes.

Also shifting into N isn't great as brake systems are calibrated assuming that there is drive going to the driven wheels. Going into N removes this and makes the wheels more likely to lock.
Sure ABS will sort this out eventually but the quickest way to stop is to not trip the ABS in the first place.
Given that the Prius is regen'ing the battery under no throttle it's probably the opposite where the brake balance is set such that there is already an assumed braking load on the drivetrain from the motor charging and in this case you'll more likely to lock the rears first before the ABS can step in.

 

I have some vague recollection of this snow stuff

 

Go stick your head in the icebox for awhile; it will refresh your memory.

Tom

 

Smirk