Prius Generations

Hi Patrick,
The shop manual was preliminary version, so numbers looked little vague.
The final version will be available by mid March.
I'll follow up then.

Ken@Japan

 

I agree with Pat. Looking at the schematic attached, it seems to me (guessing in the dark!) that Toyota have retained the 2 stages of the final gear train, prior to the differential unit, but accommodated the reduced MG2 torque by re-sizing the Counter Drive, the Counter Driven and Final Drive Ring gear. The MG2/Final Drive ratio on the G2 Prius is 3.905, and my understanding is that the max. speed of MG2 is limited to 6000 RPM.
If the latter speed limit has now been increased to 13500 RPM (which seems awfully high), then there has been significant change to the intermediate gearing, to an equivalent of 8.786 ratio, presuming that the top car speed has remained the same. That increased ratio would also improve the 0-60 mph acceleration time.
Now whether or not they have retained the silent chain as part of the final drive seems to be a mystery. Did any of you ask the question of the Chief Engineer in Chicago?

 

I thought MG2 max RPM is 13,500. It is roughly double the Iconic 6,700 RPM. The chief engineering said the PSD ratio will not change. Therefore, SRU would have to slow down MG2 by half, doubling the torque. i.e. 153 lbs-ft x 2 = 306 lbs-ft.