Currently, in the United States, diesel fuel is taxed significantly higher than gasoline. This has been a deterrent from the utilization of the more fuel efficient engines automakers possess. An example would be, in Europe, the diesel variation of the Ford Focus gets a whopping 70 mpg. While the American, gas version, gets a measly 40mpg. The cost to manufacture these engines is similar, along with things like reliability. So to the end user, the vehicle would remain similar. But the only difference is the fuel savings. This would not only help your bank account, but the environment would also benefit. So let's encourage a reduced diesel tax, and incentivize automakers to use these engines!