goal is to go as fast as you can. IF your "dial index" was 16.8, then if you ran a 16.5, you'd be 3 tenths faster than your index. But, you have to go through the entire penalty box, adding or subtracting from your ET (starting with 15.9) for each item. Pretty easy. So you might add for your weight, but have to subtract for a 4bbl, subtract for 3.23 gears, but add again for a 727 tranny. just an example