When gas prices spiraled out of control recently to the $4.00 per gallon level, many people had to change their driving habits because they couldn’t afford to gas up their vehicles anymore the way they used to. This especially affected owners of gas-guzzling SUVs and trucks, which could cost upwards of $100 to fill the tank. Naturally, when situations like this arise, there will always be a segment of society out there hoping to profit from them, and the gas crisis has been no different. From out of nowhere, ads and emails were suddenly flying around advertising various ways that people could dramatically increase the gas mileage of their trucks. The following are some of the methods being touted. I will leave it up to you as to whether or not these gimmicks work, but keep in mind that several major magazines have reviewed all of these car accessories, and have yet to find one that increases gas mileage as advertised.