reduce the nation speed limit to 55 miles per hour. saving gas and lives

As a non scientific experiment I drove my 8 cylinder 4 wheel drive truck at 55 mph from Los Angeles to north San Diego county. My average mpg was 23. On my way back I drove at 65 mph (the speed limit) and was getting 16 mpg. Every time I would drive 55 on the freeway I had very similar results. So to reduce our usage of oil it only makes sense. It will only cost time and save money.