For anyone who wants to drive their auto like a stick, remember this: a manual tranny has a direct mechanical connection between the engine and tranny, so holding anything under redline won't hurt much. But an auto tranny has the torque converter, which, as many of you may know, is a big drum of fluid that get whipped into a frenzy when you accelerate. The pressure created when you rev the engine forces the blade on the transmission side to start turning. Now, what do you think the fluid pressure is gonna look like when you hold first gear and your doing 6500 rpm at 25 mph? Yep, you're making an ATF whip cream topping. Over time, this breaks down the fluid to the point it's black instead of red and then you've got trouble.