In 2004-2005 I worked in Cedar Rapids, IA. Had a 5th wheel RV towed by a 2003 Toyota Tundra. That was when ethanol was being pushed into almost all gas in IA. I experienced a mileage decrease of about 3-4 miles per gallon. Shell at that time had non-ethanol. That was the only fuel I would use, even though the cost per gallon was higher. As time went on, often could not find non-ethanol at Shell even across TX, LA, MS, AL and FL. Retired, 5th wheel RV has been sold, still difficult to find gas that provides initial miles per gallon without paying significant increases.
Can you even find leaded gas anymore?