Results

These are the times that I recorded for each of the fuels:

Fuel (water/salt) Average Time (seconds)
Water with no salt Car wouldn't start
100 ml / 10 ml 2.41
200 ml / 10 ml 2.57
400 ml / 10 ml 2.45
500 ml / 10 ml 2.61
1000 ml / 10 ml 2.48
4500 ml / 10 ml 2.52
5000 ml / 10 ml 2.57
6000 ml / 10 ml 4.53
7000 ml / 10 ml 4.52
8000 ml / 10 ml 4.51
9000 ml / 10 ml 4.44
10000 ml / 10 ml 4.20
11000 ml / 10 ml 4.12
12000 ml / 10 ml 4.15
13000 ml / 10 ml 4.11

Graph of my results