Manual transmission vehicles generally offer better fuel economy compared to automatic transmissions, although this advantage has diminished in recent years due to advancements in automatic transmission technology. Historically, manual transmissions delivered around 2-5 miles per gallon more than their automatic counterparts. For instance, studies have shown that manual transmission cars can achieve an average of 2.94 more mpg than automatic transmission cars. However, since model year 2016, improvements in automatic transmissions have made them more fuel-efficient, sometimes even surpassing the fuel economy of manual transmissions. Despite this, manual transmissions still tend to offer higher mpg, with an average advantage of around 3 mpg when compared to automatic transmissions. It's important to note that fuel economy also depends on other factors such as the vehicle's weight, acceleration, and the driver's personal driving style and habits.