Make sure the gas cap is on tight. One reason you may not be getting the mileage you expect is because there isn't as much gas in your tank as you think. 147 million gallons of gas were lost last year due to evaporation. Why did it evaporate? The gas cap was not on tight. So just make sure it is tight, and it will enable you to keep all the gas you pay for
Having one theory is setting a limit on your potential and the potential of the overall theory and subject you are working on. Having multiple theories gives you a broader idea and perspective of what is going on, and even though one may slightly contradict the other, it is okay because that is what theories are for.
To the point, scientists usually have more than one theory so that they can gain a broader perspective on the matter and maybe even increase the chance of being correct on the matter.
Hope this was helpful.
Cheers,
First four are made of rock and rest are made of gases.
Atmospheres of all the planets are made of gases.