There's a very small amount of time you can save/lose in the World Tournament based on what character you choose to play as and what character you face. Here's the length of each name spoken by the Tournament announcer in seconds. (English Version)

There are also characters that take longer to load than others on certain consoles. For PS2 I've confirmed that Frieza is the absolute slowest to load in - and Goku and Vegeta are slow as well.

Goku Vs - 1.88 Goku - 1.64

Gohan Vs - 2.07 Gohan 1.69

Vegeta Vs. - 1.84 Vegeta 1.2

Krillin Vs 1.79 Krillin 1.58

Trunks vs. - 1.84 Trunks 1.58

Piccolo Vs 1.7 Piccolo 1.5

Tien Vs. 2.08 Tien 1.6

Yamcha Vs. 1.79 Yamcha 2.22

Raditz Vs. 1.84 Raditz 1.63

Nappa Vs. 1.78 Nappa 1.67

Ginyu Vs. 1.78 Ginyu 1.6

Reccoome Vs 1.88 Reccoome 1.72

Zarbon Vs. 1.9 Zarbon 1.72

Dodoria Vs. 1.93 Dodoria 1.71

Frieza Vs. 1.87 Frieza 1.70

Android 16 Vs. 2.81 Android 16 2.74

Android 17 Vs 2.96 Android 17 2.72

Android 18 Vs. 2.72 Android 18 2.36

Android 19 Vs. 3.08 Android 19 2.49

Cell Vs. 1.79 Cell 1.49

Hercule Vs. 2.25 Hercule 1.90

Gt. Saiyaman Vs 2.25 Gt. Saiyaman 1.97