From the FAQ on their site:
Quote:
Can I double the amount of additive suggested on the label?
While we recommend using our fuel additives as directed, each product has been through rigorous “no harm” testing and may be used as often as every tankful. However, a stronger concentration of the product may not provide any additional performance benefit over the recommended dosage.
That said, with my Scion I did a double dose (1 full bottle for a 14 gallon tank) the first time I used it @ ~30,000 miles.
I do a 1/2 bottle every 5000 miles now (although they do recommend every 3,000 miles).
I do a full bottle on my truck (25 gallon tank) just before every oil change (4,000 - 5,000 miles).
I also did a full bottle on my moms Saturn Vue with 120,000 miles (16 gallon tank), sisters Hyundai Santa Fe with 130,000 miles (18 or 19 gallon tank).
I did 2 bottles on my brother in law's F150 with 150,000 miles (30 gallon tank) that was running horribly (clogged cats was the issue, but what the heck).
But then again, I have a little to spare...
