shifting into neutral when driving to increase mpg

Maybe someone with a scangauge can verify; if you are traveling downhill and engage neutral while the ice is on, the ice rpm will increase as the speed of the vehicle increases? In my altima hybrid that is the case, the rpm will increase while in neutral to match the vehicle speed, therefore negating any fuel savings by being in neutral.

 

No, it will run at idle.

Of course, a major part of the fuel economy benefit to using neutral in the Prius is shifting when the ICE is off so it remains off for as long as the car is in neutral.

 

OK, the pulse and N-glide while <= 40mph sounds pretty good, esp. if you've reached S4.

On the other hand, all this shifting from D->N and back is going to cause additional wear and tear on the shifter. The question arises whether this will result in significant chance of failure of the shifter with subsequent need to replace it...and how much does it cost to replace the shifter (parts/labor)?

 

The shifter is just a switch assembly. It is fairly easy to replace and is inexpensive.

Tom

 

Another question:

Does switching between D and N could cause harm/wear to the electrical system components?

I found that when I switch “gears” at low speed, I feel a jerk in the “transmission” while doing so. Does this leads to an electrical pike in the inverter? At higher speed the jerk disappears but the phenomenon may be even more important while not visible.

As anyone tested this with a ScanGauge to see what the inverter current/voltage are when doing this “gear” switch?

 

I haven't tested with ScanGauge, but I am reasonably certain that there are no fish in the inverter. Things can get fishy, but that's only an expression.

As for the jerk (and no, I'm not talking about the person typing this message), it is the inverter applying a drive voltage to the MGs. These sort of electrical transitions occur thousands of times per minute and shouldn't be a concern, since this is designed function of the drive electronics. Once we get into worrying about transistor cycles we are officially over-thinking this issue.

Tom

 

My understanding is that the mechanical limit on the 2004-2009 Prius is 6500 RPM and the 2010 Prius is 10,000 RPM but they kept the electronic limit. Now if I can only remember where I read that, but I think I started from one of the threads on IGN 14, and maybe went to cleanmpg.com in the process.

 

Tom, I think Philosophe misspoke, and was actually referring to the new bio-hybrid system using electrical eels. Test results show it works pretty good but you need to stop every 100 miles (150 miles for hypermilers) and feed them some minnows.

Now a spike in the inverter, that might be a problem. Particularly a railroad spike.

 

Perhaps put a scoop in front and feed them the occasional jogger or bicyclist.

I think you use a wooden spike on hybrids, just as you do with vampires. This is the recommended solution for SUA.

Tom

 

Thank you all for noticing my unintentional pun.

Tom,

I understand that the system takes good care of itself but this "jerking" effect (feel free to suggest a better word!) is not usual (the HSD normally doesn't do that, it always transition softly). I was simply wondering if a driver constantly shifting between D and N could cause a slow, unintentionnal, wear to the system (mechanically to PSD or electrically to inverter).

 

Welp, even if you managed to break the shifter by using it excessively, there are plenty on ebay to be had for under 200$.

 

Noticed something interesting doing P & N-Glide this morning. Whenever I shift into Neutral, the B position on the display goes away. Then when I shift back into D, it reappears...weird.

 

B is only available while in D so it's not displayed until you shift to D.

 

i understand that the PSD contains no detachable gears -- all the eCVT magic happens in the control logic governing RPMs of each of the 3 gears. Thus there is no mechanical Neutral, only an electronic or logic one. Am I correct ?

 

Correct. The two electrical motors will simply spin freely.