I took a college class for automatic transmission and the purpose of the manual 3rd was not covered. I know that manual 1st is used for maximum engine braking under 40 mph when descending a hill, and manual 2nd is used for acquiring increased power when attempting to pass another vehicle. But I do not know what the prupose of the manual 3rd gear is because we covered the late model GM 3T40 automatic transmission that only has the manual 1st and 2nd option.

In some transmissions you can shift manually and automatically so to speak. That may be one reason.

Although, in some cars you may have something called "OD off" or overdrive off which is probably similar to manual 3rd. If so, then it forces the car into a "better fuel economy" type of mode when driving the interstates. Accelerating won't shift to a lower gear.

While we are on the subject, the "traction control off" button really doesn't make a lot of sense, name wise. If you drive in the snow or rain, you want traction control to be off. You might reason that it should be on because you would like more traction in the snow, right?

What "traction control off" does is it keeps the wheels spinning at the same speed. What was called "positrac" differential long ago. When trying to get out of snow, you don't want one wheel to spin faster than another because you might get stuck. In the rain, you may slip.

But, when going around corners on dry pavement, you woud like the wheels to be able to spin at different speeds giving you more traction around a corner. May be it should be called "snow, rain and ice" mode, but that's too many words.

Same deal, foreighn cars for years had the ability to run the AC and heater at the same time. If you own a car that allows that and it's raining on a very cold day. Run the AC and heat at the same time and use recirculate mode. The AC will remove the moisture and the haeter will re-heat to the proper temperature.

Also, you get the option of Defrost (Heat with no AC) and defog (Heat with AC) with that type of control.

Good luck in your studies and have a Merry Christmas.

I was just looking for the benefits of shifting into manual 3rd. Just to keep it simple. But thanks a lot for taking the time to help me out. And have yourself a Merry Christmas as well.