The fourth one controls recirculate, and it allowed you to set in-between positions between 100% recirculate and 100% fresh air.
To simultaneously optimize pollution/humidity/CO2 I find I prefer about 80% recirculate and 20% fresh air, but achieving this configuration is impossible in most (all?) modern cars.
That's the workaround I'm forced to use, but obviously the disadvantages are noise exposure and forgetting it's cracked resulting in rain entering the car. :-(
Yay for "progress" eh? I know the recirculate door servo can stop halfway, just let me control it...
I used to do it in my former Skoda Fabia and the window just collapsed. Thank Indian roads. I noticed there is a subtle final movement from "cracked" to closed and I guess there is a big difference in vibrations related wear.
Toyota ran ads encouraging owners to crack windows in the rain and I noticed no final movement. But I'm not risking it.
Simplicity: are they exactly the same knob, thus lowering ordering costs, shipping and receiving costs, inventory costs, supply chain costs, design costs, and error potential? Quite likely. This also allows upstream suppliers to double down on volume and work to lower costs at their end.
Versus... the designer of a custom complex multi-part powered assembly (manufacturing cost not discussed, cleaning not discussed, visibility in varying light conditions not discussed) who has the fantasy that users want to squint at a tiny screen on a knob while driving, and that pushing all this and associated documentation down a global service network is going to come at an acceptable cost to users.
Why is it that when the entire auto industry does something right Toyota gets credit? Fanboyism is a pox upon online automotive discourse.
Every OEM has used the 3-knob design on and off but it was particualrly hot in the 90s and 00s. It isn't a Toyota thing, or even a specifically Japanese thing.
.jpg?t=167848960503){kind=link}
https://i.ytimg.com/vi/W9AjhGko2mA/maxresdefault.jpg
The fourth one controls recirculate, and it allowed you to set in-between positions between 100% recirculate and 100% fresh air.
To simultaneously optimize pollution/humidity/CO2 I find I prefer about 80% recirculate and 20% fresh air, but achieving this configuration is impossible in most (all?) modern cars.