I have been unsuccessfully trying to find some in depth information on the design and operation of the ECVT. I even bought a 24 hour subscription to the Toyota technical publication website but could not find much detailed info. In particular I am interested in the following:
1) How is the ICE (engine) coupled to the tranny? Is there a torque converter, electric clutch, etc.
2) When the engine is "off" does it disengage from the drivetrain? The car coasts as though it is in "neutraL".
3) What are the range of drive ratios? (I wish this car had a tach instead of that useless energy meter!)

It is connected through a planetary gear set with the ring gear driving the front wheels, the ICE connected to the the spider of the planet gears, and the sun gear connected to a generator. The electric drive motor is also connected to the ring gear. The gear set acts as a power split device, continually splitting and modulating the power between the ICE and the electric motor. You really need to see a drawing to be able to think through how it works and how the gear ratios can continually change. Also requires familiarity with the theory and workings of a planetary gear set. There is no torque converter or electric clutch. You might find some of this info on the Lexus Hybrid web site.

Here are some links with information on Toyota CVT. Some are specific of the Prius, but the ECVT is very similar if not identical to the Lexus one. Also find a picture of the real gear.
http://homepage.mac.com/inachan/prius/planet_e.html

http://prius.ecrostech.com/original/Unders...ransmission.htm

http://prius.ecrostech.com/original/Unders...SplitDevice.htm

Thanks! These were a great help in understanding how the drivetrain functions. Still wish it had a tach!

http://www.scanguage.com

I have one. It works well. Does much more than check and clear 'check engine' lights. Tachometer is one function of many.

Lemon, would it be practical to move the Scangauge from one vehicle to another? Would it require only a second pair of cables?

Tom

Yup. Just the second set of cables, or if you haven't got the cable routed all under the dash, just move the whole thing.

It looks very interesting. Where did you mount it and how did you route the cable?

Unfortunately this is OBD2 which won't work on older vehicles, like my Porsche 968. Bummer.

Tom

Ahhh, now that's project I'm still working on. I picked up my 400h in June to replace a Subaru Outback. The Scanguage was beautifully mounted in the Suby in a nice cubby hole in the dash under the radio. It looked like it was meant to be there. I haven't taken the time to really consider where it might fit in the Lexus yet, but I don't think it will fit right in like it did in the Subaru.

I have had it hooked up while driving and it works fine in that regard.