I know I'm leaving myself open to ridicule by saying this, but a couple of times I've found myself moving with the freeway traffic at high speeds, especially in the HOV lanes where I don't want to be the bottleneck. I've noticed that at about 83 mph, if I add some gas, the engine/transmission makes a sound similar to what I used to associate with a slipping clutch. You know, the engine speeds up but the car doesn't seem to be getting all the torque. It does speed up, but this noise bothers me. Is something slipping, besides my brain?
No. Prius engine RPMs are not directly related to road speed, and the engine needs to rev up to provide the necessary power through the electric generators and motors. For the same reason the engine will roar when going up a long grade at speed. It's normal.
<div class='quotetop'>QUOTE(richard schumacher @ Aug 12 2006, 09:18 AM) [snapback]302133[/snapback]</div> Thanks. That makes sense. In all other cars the ICE is just used to power the wheels. I forgot that in this one it also has electrical duties. It's a pretty smart transmission that can maintain a smooth ride while the engine is jumping around in speed.
The fact that you're running the engine power output up that high to maintain 83 mph should, um, tell you something. . _H*
<div class='quotetop'>QUOTE(hobbit @ Aug 12 2006, 10:56 AM) [snapback]302172[/snapback]</div> You got me......
<div class='quotetop'>QUOTE(Alnilam @ Aug 12 2006, 10:09 AM) [snapback]302157[/snapback]</div> The Prius does not have a transmission in the traditional sense. It has a planetary gear power splitting device.
<div class='quotetop'>QUOTE(Alnilam @ Aug 12 2006, 01:53 PM) [snapback]302247[/snapback]</div> Yeah, me too Bob, I'm not sure just exactly what hobbit meant, but I'm fairly certain that it is either related to greater fuel consumption at high speeds or it is related to the engine RPMs going someplace. That is the important part to consider with the Prius, engine RPM always has to go someplace. It is either being directed to the wheels, or to the MG or, in most instances, to both. In that sense, we can also agree that there is no slippage, because the engine is physically connected to gearing which is in turn connected to electrical devices or the final drive.
