Toyota’s New CVT Has A Launch Gear
Jason from Engineering Explained is back with some more knowledge, and since we love ...
Jason from Engineering Explained is back with some more knowledge, and since we love his videos and how he breaks things down so well. This video features information about Toyota’s new CVT (Constantly variable transmission) and a design they’ve incorporated to help get vehicles equipped with this transmission up to speed in a more efficient manner.
For those who don’t know, a CVT is exactly what its name implies – a transmission that has a constantly varying ratio. What this does is eliminate a lot of the complexity inside the gearbox and helps keep the engine in its most efficient RPM range. However, one of the inherent design flaws in this setup is the lack of efficiency at either end of the MPH scale.
To address this problem, Toyota has incorporated an additional direct drive mechanism that works, for all intents and purposes, like a two speed transmission… sort of. The overall ratio of the CVT itself is shifted toward higher vehicle speeds, then the “launch gear” as it is called, works down low in the MPH range – specifically when taking off from a dead stop – to keep the engine in it’s most efficient range again.
One of the selling points of the CVT all along was that you’ll never feel the transmission shift, but it turns out that most people seemed to find that sensation unusual, if not unnerving, so many automakers have incorporated a system that is still a CVT, except instead of having the tension adjust gradually to keep the engine in it’s most efficient range, they’ve added a set of faux “shifts” in the process that makes it seem as if the car is actually shifting from gear to gear.
This set of changes should serve to keep the car just as efficient as always, while adding a little more “oomph” to the bottom end, which is a win/win for all of us.