http://www.ca40g.com/home.php?xid=8b97bd90c4646e98ec9ed3973adeb3f5

Most people I've talked to that have tried to run it in their vehicles have been unable to successfully replicate improvements due to variables such as wind, load, etc.

I should have tested some this spring while planting as the tractor has a fuel meter and it would have been a good test over a long time to see. Might have to next year.