Shifting Gears

I dont know a whole lot about shifting gears on car but, my Alero has gears 1, 2, and 3 on it. I was wondering if i could use these to manually shift as i drive? And if so, what speeds am i looking to use these certain gears. I looked everywhere and couldnt find a thing about explaining how and when to use them. If anybody could tell me id be most appreciative.

Welcome to AF.

You have D, 3, 2, 1. D is also overdrive or 4th gear. Basically it is a 4 speed autotransaxle. You can manually upshift or downshift as you drive. 1 is the lowest gear or first, 2 is second gear and 3 is third gear. D is 4th (OD) and when the torque converter clutch locks up and unlocks. When to upshift or downshift varies depending on driving/road conditions, speed and engine rpms.

For example when we race our Alero we start out or stage with the shifter in 3. Accelerate and then watching the tach manually upshift at around 6000 rpms to 2 and etc. Also, you can use the shifter to downshift but you have to watch speed and rpms so you do not overrev.

However, for overall fuel economy and driveability on the street best to keep it in D andf let the transaxle work automatically.