An extra edge
Many additives contain more than one type of fuel improver. “I personally recommend choosing a multifunction additive from a company that has been around long enough to really know what works and what doesn’t,” Williams says. “Pick a company with a good reputation and try out their additives for a few months.” Also, ask other drivers you trust what has worked for them.
With so many additive options, we advise you to read labels carefully and choose wisely, with an eye on your engine’s specific needs.
“Rather than individual ingredients that may or may not be included in an additive, drivers should look for the functions specified on the additive label and match these to their particular need,” Williams says. “For example, there are a number of ingredients that may help remove water from the fuel, therefore drivers dealing with water in their fuel need to reach for an additive that functions as a water emulsifier.”
Take care when choosing an additive not to sacrifice one benefit – say, long engine life – for another – say, fuel mileage. Williams warns against using additives that include “ferrous-type chemicals and compounds. These ingredients have been shown to have some benefit on increasing fuel mileage, however they do not completely combust with the fuel.” The remnants can damage the engine over time.
“The best defense is a good offense,” Williams says. “Drivers need to be assertive about getting on a regular maintenance routine of using good additives before they start to see problems.”
Additives are relatively costly, highly concentrated products that modify a fuel’s behavior. They work most inexpensively at small concentrations. That’s why Lucas Oil Products, Inc.’s Forrest Lucas says there is a point with their additive past which doubling their treatment rate will not help a bit. Yet treating at 1/2 or 2/3 the recommended rate, “you won’t get the benefit.”
“Know what your fuel tanks hold and do the math,” Lucas says.
Make your calculator your friend, and mix at the recommended rate per gallon of fuel. Packages often are sized so one will treat 100 gallons, meaning you can just pour one full package into a typical full fuel tank.
Power Service Products’ Ken Stratton believes that on older fuel systems where the fuel does not circulate continuously back from the engine, “There may be some slight benefit to filling tanks after the additive has been added.” This will help it mix uniformly.
Diesel fuel has to do so much that you’ll be smart to doctor it with the right stuff. Read the package carefully, look for test results when an additive claims to improve fuel economy except by cleaning injectors, and make sure to keep your lubricity up and your cold filter plug point down.