These rules include:
- The gas tank can be made out of either a rigid or flexible material
- If the fuel tank is made from a rigid material, it may not carry any structural load
- If the fuel tank is made out of a flexible material, it must be enclosed in a rigid container, which can be load carrying
- There is no explicit size limit
- It must be able to be emptied at any point in the competition
- It must be mounted inside of the top roll hoop and inside of all four tires
- The filler neck for the fuel tank must be at least 1.5" in diameter, 4.9" high, and at no more than a 45 degree angle from the vertical (see picture below for clarification)
- The filler neck must include a clear sight tube to be used to check the level of gas while filling the tank
- The filler neck may be used as a sight tube
- On the sight tube, there must a a line .5" to 1" below the top of the tube to use as a fill line
In addition to the constraints laid out by the 2013 FSAE rules our design was limited by packaging constraints that we determined had to be there because of of all of the other things that needed to be packaged within the space-frame chassis. This meant that we were trying to keep the tank as small as possible so that other important components could be integrated within the chassis as well. The final constraint was one of size that was determined from past performance in the endurance race that takes place at the FSAE competition. Being the longest dynamic judging event at the competition a baseline minimum was set at 1.5 US Gallons, this figure comes from including a safety factor over the actual amount used in the previous years endurance test which was 1.282 and 1.022 for 2011 and 2012 respectively.
