I just purchased some Power Service Diesel Kleen + Centane boost additive for my recently purcahsed 1994 Ford F250 IDI Non-turbo. The instructions call for a dilution of 6.4 oz per 20 gallons for a Cetane boost of 3 and 2X that dilution for a Cetane boost of 6 . I am not very interested in the Cetane boost aspect as I am in cleaning the injection system and making it last . What is the appropriate dose to use . - thanks