Tesla doesn't want any of its customers to miss out on its aptly-named Ludicrous Mode, and is now offering the speed boost as an upgrade for the Model S P90D. For $10,000 plus taxes and labor, P90D owners can have their car retrofitted, decreasing its 0 to 60 mph time by 10 percent to 2.8 seconds, and making its 0 to 155 mph time 20 percent faster than a standard Model S.
Previously, Ludicrous Mode was only available as an option when customers first purchased the P90D, but the retrofit lets anyone who ignored the upgrade first time round get a second bite of the apple. Telsa did something similar with the P85D, offering the same retrofit when the previously-top-of-the-range car became outmatched by the new P90D.
According to Electrek, the retrofit itself consists of two main changes to the battery pack of the Model S: the fuse is replaced with a "smart fuse" which can more precisely monitor the battery's current, and the battery's contactor is upgraded from regular steel to the aerospace-grade alloy Inconel (used by SpaceX to build its rocket engines). These changes combined up the car's power output from 1,300 amps to 1,500 amps. Oh, and Tesla also underlines the "P90D" on the car's badge, just so people in the know, know that you got the upgrade.
Verge Video: Driving the insane Tesla Model S P85D