Help! anybody please! im desperate =(

Ok.. first of all im pretty use to converting files and burning them on dvd from avi>mpeg format.

for a while now i could fit around 8 episodes of 500 mb files (for a lil above minimum quality per dvd.

but now.. i want 13 episodes on a dvd .. so i won't have to make 2 unnessesary DVD's splitting 7 epis. and 6 epis. Each episode is like 25 minutes long.. even with the minimum compression TMPGenc gives me.. i can't pull more then 9 episodes. I see people who have like 13 episodes of a series on ONE DVD i'd like to know how too..

im gonna source the size to buy me like 3 minutes off each episode.. but im still over limit.

i was gonna post pictures... but i didn know this site didn support direct pic links -_-

so basically the problem i have now is... how do i fit 13 episodes onto one dvd without splitting 2 dvds.
any advice will help me out.. thanks alot everybody.
this will save me ALOT of money and time.

if you would like more description of my problem let me know