Is shifting to neutral at red lights bad for transmission

You won't hurt the car, but see this thread for details on why it isn't a good idea:
Shifting to neutral to avoid engine braking | PriusChat

 

Useless but harmless. You may not be cheating yourself out of MPGs but that is not what you asked.

 

i do the same thing. my father taught me to drive like that (what if you have a heart attack at a red light and the car rolls forward and hits somebody?) and i can't break the habit.

 

years of riding Harleys has taught me to always be in gear at anytime on the road, even at red lights. and the same habit for me driving any cars too. i can hear that distinctive click as calipers lock with the ensuing swish of silent skidding to my side rear or behind and then I gas it to save my assets,,, pure instinct,,, sorry, i have never heard of using neutral,,,
~~ worse case scenario is "sorry officer, i ran the red light because in heard a swish sound"
~~~~ what actually has happened i heard the click and then a swishing sound , so i gunned my bike right thru the intersection ,,, it saved the cop's life because as he looked up to see me loud as hell go past him and his outstretched hand right behind me was the old man in the dodge dart still skidding (towards the cop who assumed everyone had stopped),,, no way will i ever put my car/bike in neutral. (and thankfully the cop was ok and the construction workers too).
~~ drive safe. always keep your control of your vehicle. ride safe.

 

This is only my opinion, but, if you're in neutral and on the road you don't have full control of the vehicle. If for some reason you had to accelerate out of a situation and were in neutral you would have to identify the problem, react to it , and then put the car into gear before you could accelerate. All of the time used up before you can accelerate is time that might prevent you from avoiding a situation. Granted it might be only a fraction of a second, but, it might be what was needed. The only time I would consider taking my car out of gear is if I were on black ice and engine braking was causing the car to go into a slide that could not be controlled, but, then again I use very aggressive snow tires so hopefully this is not likely to happen.

 

I'm glad I'm checking all the forums...was just going to ask the same question.

 

What if your HV battery is low because you've been stuck in heavy traffic for 20 minutes and have your a/c on high because it's a hot day, you then stop at a Red and slip into Neutral. Your car can't attempt to charge the HV battery if it gets too low and this could cause issues with fuel economy at the very least and possible damage to the HV battery as well as the car refusing to start?

Happy to stand corrected.

 

All of that is true, and I think it is senseless, but the question was is shifting to neutral harmful to the car and it isn't. It will lower your MPG, but that is not the question.

 

The practical side of me wonders about all of the extra wear and tear on the shifter assy itself, and on the diodes/capacitors/transaxle/MG's for doing this.

The Prius is such an intelligently designed car, I see no need to shift to neutral when coasting. Let it do its thing on its own.

 

I'm with kalsifur on this. Using N below 7 mph seems to make sense sometimes. I do it when I'm creeping downhill in traffic, and think it's silly that the car us using the battery to creep the car downhill while the friction brakes are engaged. It's the same situation that I'm in neutral with a manual transmission because I'm not going fast enough to fully let the clutch out in first gear.

There's no wear issue with the motors or electronics because the electricity is normally being switched on and off thousands of times per second, and N simply keeps all the switches "off".

 

I know it's your car and you're happy switching into Neutral and I understand why, but surely any slight benefit you gain from doing this is immediately wiped out 3 seconds after you start up your Mustang.

 

The benefits are entirely psychological

 

With our previous Civic hybrid with it's traditional CVT (if that makes sense) I'd frequently push into neutral, for rolling to reds and while stopped. The car would typically auto-stop once warmed, but when it was running and stopped, neutral really smoothed it out. With the conventional shifter it was much easier to shift.

With the Prius though, I put it in drive, never touch it again.

 

i didnt realize the Prius shifter was so very different from the more traditional shifter on the c. now i can understand why the concerns about neutral and park.

 

I'm curious why you let off the brake once the car is doing less than 7 mph; I can see no benefit whatsoever. My car if I released the brake would roll for a considerable bit. Besides, the electrical feedback continues til the car stops so rolling the last 7 mph does nothing except extend the stopping distance.. Its harmless I agree unless you think throwing away the last bits of regeneration is bad.

 

I'm guessing they do it because there is no regen below 7 mph.

Why they bother is certainly questionable and I just couldn't be bothered with that sort of OCD shenanigans, but it's their car so I guess they do what they like.

 

Note that below 7mph the car switches from regen to creeping (using the battery to power the car against the friction brakes), and sometimes that seems totally ludicrous, like when stuck in traffic inching down a hill. Yes it is OCD, but it also gives me something to do when I can only drive three car lengths each light cycle.

Speaking of using neutral downhill, a few decades ago I had a 4-speed Chevette, no power steering or brakes, that would regularly stall when coming to a stop at this particular intersection. Only a few cars would get through each time the light turned green, so I'd leave the car stalled and just coast down the hill a few car lengths at a time, then restart at the bottom of the hill (many times while coasting with the clutch in) and drive off. Back then I didn't even know that was called hypermiling

 

The real reason we are having this conversation.