Carbon negative fuel isobutanol as the gasoline replacement has been described and the gas mileage was provided for the two cars: the 2020 Toyota Camry and the 2020 Porshe Cayenne Coupe Turbo. In addition, the gasoline replacement by carbon negative fuel diacetyl alcohol was tested. Upon reaching 20,000 miles for both said cars, the cars were examined by the independent mechanics from Toyota dealership and from the Porshe dealership. The same has been done on the similar cars the 2020 Toyota Camry and the 2020 Porshe Cayenne Turbo fed with the gasoline replacement diacetyl alcohol. The fifth corporate car 2020 Shevrolet Silverado 1500 was used to test the carbon negative diesel fuel replacement diacetyl alcohol for 10,000 miles. Diesel fuel replacement was made by condensing two acetone molecules into diacetyl alcohol used to replace diesel fuel. 2020 Shevrolet Silverado 1500 was tested by the Shevrolet mechanic. The mechanics did not identify any problems in said new engines of all the cars tested.