First Impressions of Buick Lucerne

[tenders]

modelamac wrote:
If you are really sensitive, I think you will find that it has the torque converter lockup in both 3rd and 4th gears, making it essentially a 6 speed. My 200 Chevy Venture has this, as did our 2003 Saturn Vue v-6.

Could you explain this? I thought torque converter lockup increases the efficiency of an automatic transmission in high gear using a mechanical connection instead of a fluid connection during prolonged operation in the same gear.

What good is it in the second-to-highest gear, and how does this make a transmission like a 6-speed?