Truckers breathe a sigh of relief as they see the numbers on signs at truck stops go down. From last month, diesel prices went down $0.03 and will continue to drop. This time last year, diesel prices were $0.30 more than they are now! Finally, driving is less expensive and less stressful. Taxes play a huge part in the price of oil. So, as the tax price goes down, so does the price to fill up your tank.