A4 and Top Speed Runs

[99CamaroV6]

I've noticed something weird over the years and maybe someone could care to enlighten me...

If I leave it in D (3rd) I can go in 3rd gear all the way to 118 and I'm hitting exactly 6,000rpms.

If I leave it in (D) (4th) once I hit about 111 it'll shift into 4th and accelerate like a snail (in comparison) to 118. My question is...WHY on EARTH does the transmission shift way below redline in 3rd gear when it actually slows the car down. The only time I don't leave it in (D) when I race/jerk around is when I plan on hitting 110+.

[MrCoffee]

overdrive is to save gas. Easiest way to save gas is to keep the RPMs down. So you get slower accel, and sooner shifts in overdrive, but better gas milage.