• Keith Posted: 5/27/2009 7:12am PDT


    Last paragraph says "Milan". That should be "Mariner".
    @Oldsmoboi: Some hybrids do and some do not have 12V batteries. But ALL have 12V busses. The Highlander Hybrid (same as all others) has a 12V jump-start point (to or from), whether it has a 12V battery or not.
    The Prius does NOT have a CVT. Same as all other Toyota, Lexus, and Ford hybrids, the single planetary gear set can only transmit a multiple of the torque provided by the motor/generator on the sun gear. The engine speed is controlled by the speed of that same motor/generator. The resulting behaviour is CVT-like, but is not the same, as CVTs (and fixed-gear transmissions) provide engine torque multiplication at lower ratios, but the hybrid's planetary gearsets do not.
    The GM 2-mode is an extension of the Toyota/Ford system, in that it uses two planetary gearsets, the primary benefit of which is to allow downsizing of the electric power used for ratio regulation. The other benefit is two planetary gearsets, with appropriate locking clutches, allows four fixed mechanical ratios, which again minimizes the electrical power usage.
    Note that the single-planetary-set hybrids could have two fixed mechanical ratios by adding a couple of cheap locking clutchs. The main cost would be the engineering cost to program the controls. But as far as I know, nobody is doing it. Given the cycle fuel efficiency of the Fusion over the Camry and the HS250, perhaps Ford has done this but hasn't published it. Someone needs to do a teardown and see!

  • Oldsmoboi Posted: 5/26/2009 11:38am PDT

    "Well... sorta."

    These 6 things may be true for the Mariner Hybrid... but not all hybrids are the same. The Honda Civic hybrid is just an electric motor in place of the flywheel of an otherwise conventional engine. It has a 5-speed manual or a CVT just like conventional cars.
    The Toyota Highlander Hybrid appears to have a 12 volt battery. The only reason I know this is my neighbor jump started my partner's CRV with a Highlander Hybrid.
    The Pruis has a planetary gearset (the same basic concept used in the Ford Model-T) and a Continuously Variable Transmission(CVT). It may not be your standard 4-speed automatic, but it's still a transmission.
    With the GM 2-mode hybrid, all of the hybrid mechanics is in the automatic transmission.

  • R2dad Posted: 5/26/2009 10:26am PDT

    "Hybrids 101"

    Good factual article. Thanks for the primer!