Coasting in neutral

Ahhh....statistics.
Nice, huh?

From 2014:
Roadshow: Downhill in neutral is illegal and dumb, and a lot of drivers do it – The Mercury News

I'm not going to pretend that I have the answer for G4s, since I drive a G3, but for my flavor of Prius, it's pretty easy.
Driving in neutral is actually LESS efficient than driving in D......so that just leaves "illegal" and "dumb."

YMMV

 

The 2017 Prime may have changed this but traditionally N is achieved by suspending all power used/generated by any of the electric Motor/Generators. (Toyota is legally required to provide an N, they did not make it useful)

As a result in previous Prius, N always involved draining the HV Battery, a lack of Regenerative braking, and more gasoline usage to recharge the battery. (except in Plug-ins)

I would be amazed if this had changed, but I have been wrong before. (and I will be again)

 

I find the fuel cutoff discussion (about non-hybrids) in this link to be too simplistic. As I have previously posted to another thread, the answer depends on the particular situation. In some situations, N-ICE-On gliding is more fuel efficient than DFCO coasting, in others DFCO is more efficient.

Taking ScanGauge-II readings on my 1997 Subaru, N-ICE-On gliding consumed a flat 0.25 gal/hour of fuel when fully warmed. DFCO coasting wasted usable energy that varied with the situation, nothing at certain times, but reaching the equivalent of 0.60 gal/hour at other times. So the choice was a tradeoff.

Its successor, a 2014 Suby has a more modern engine with variable valve timing, reducing the N-ICE-On mode to 0.20 gal/hr. VVT and more efficient gearing reduce the DFCO wastage even more, but I don't have an equivalent number to provide. Overall, with today's more efficient engines and gearing, the window for useful neutral coasting is getting narrower all the time, especially for automatics and CVTs that allow taller gear ratios than manual transmissions.

Neutral coasting downhill was made illegal for reasons that applied far more to passenger cars of two generations ago than to today's designs. The reasons still apply to heavy trucks, but car drivers can still create the same issues if driving stupidly, so the law is not going away.

If an observing officer can tell that you are doing it, or if you need to foot brake at all, then you are doing it wrong.

As a G3 driver, I'll agree here. Previous Prius generations have already harvested most of the savings once possible with neutral gliding and incorporated that operation into D mode, albeit with a light feathering of the gas pedal to get top results. And they were even safely dipping into the fuel savings territory that non-hybrids could achieve only with the riskier N-ICE-Off mode.

The window where Neutral could be the more efficient choice, better than DFCO, was already effectively closed in the Prius family. And G4 continues to improve the efficiency of D mode.

 

Also the fact you wouldn't be able to get a car wash without the neutral option.

 

this is interesting. can anyone else test this? i can't imagine regen working in neutral. it wouldn't be neutral.

 

The car wash I use, I use with the car off. It is stationary and power is not needed. (I very rarely do use N to be sure my friction brakes are up to snuff)

 

well, that's fine for you, but the rest of us use a car wash that is in motion.

 

Some Prius lack battery power to make it to the far end of that kind of car wash. A Prime should be fine, larger battery.

 

The car wash I go to in the rare case I don't wash it myself has the rolling system, the advantage being that three cars can be in it at the same time - one getting the prewash, one getting the main wash, one getting the air dry.

 

I suspect it has to due with customer frequency. The stationary car wash I use takes about 10 minutes, but I seriously doubt more than 1 customer per half hour ever wants a car wash here. If you had a customer every 5 minutes, an moving assembly line car wash may be more profitable, even if it takes more room.

 

Of course. There are 10x more customers down here, so we need higher capacity systems to handle the demand. Until you have enough customers to have a significant waiting line form, the business volume just won't pay for the equipment.

Whether or not you even want to live in a community that that many more people, is a different issue.

At some times here, I think the rate can hit 2, maybe even 3 cars per minute.

 

ok, new topic here, "car wash"

 

That's why you have to read all threads. You never know what you'll find in them.

 

like the "box of chocolates?"

 

New topic, "box of chocolates"

 

Who here thinks this is Tom Hanks' best film? I'm thinking BIG but you also can't count out Castaway.

 

Apollo 13

 

lol, you guys took me seriously when I said "new topic"