[Rptanner]

Some of the explainers and videos on the drive system for Gen2 have mentioned an "overdrive" mode in extended range, but there was no real explanation of what it is. Couldn't tell if this was simply when the ICE directly connects to the drive gear, or something else going on. Anyone out there know what it is and how to "trigger" it?

 

[Jeff N]

Some of the explainers and videos on the drive system for Gen2 have mentioned an "overdrive" mode in extended range, but there was no real explanation of what it is. Couldn't tell if this was simply when the ICE directly connects to the drive gear, or something else going on. Anyone out there know what it is and how to "trigger" it?

When the gas engine is running on the gen2 Volt it is in one of three modes. Two of those modes are "power-split" modes where the gas engine works along with a generator and a motor through a couple of planetary gear sets to drive the wheels at effectively continuously variable gear ratios. One mode is generally used for city driving and the other is used for highway driving. The third mode is a fixed gear ratio where the engine is directly geared to the wheels. I don't remember the exact gear ratio offhand but it is roughly equivalent to 4th gear in a typical 5 speed transmission. It is more efficient in some conditions but the two power-split modes are more flexible and are used most of the time.