I'm not using the template because this is a rather abstract question about the way to approach a scientific experiment. I'm beginning a science project in which I hope to define the speeds at which using an air conditioning unit becomes more efficient than rolling the windows down in a car. Right now I'm envisioning a procedure, but I'm beginning to question the feasibility of such a product. My intent was to determine the amount of gallons the car I'm using can hold and performing trials at a constant speed. Once finished I would refill the tank and measure the difference to see how much gas it used, and then compare it to the results seen using different speeds/cooling methods. I also intended to calculate drag into my data analysis. I'd just like a general consensus on whether or not my project is actually plausible, and if so, how would I go about accounting for the unknowns such as time spent at red lights, etc. Does anyone have any ideas for more effective means of measurement? And as a more broad question, is this project too simplified for an 11th grade science fair entry? Thanks in advance for any advice!