There are dozens of fuel additives on the market designed to prevent or reduce gelling of diesel fuel in cold weather.
Winter grade #2 fuel begins to gel at 10- to 20° F, depending on its refiner. Farmers traditionally blend #1 diesel or kerosene with their #2 fuel to keep it from gelling. Professional truckers who can’t custom-blend fuel every time they fill depend on commercial anti-gel additives to keep their rigs rolling in cold weather.
The problem is that there are no mandatory standards for testing the performance of anti-gel additives. There are concerns that some additives may reduce a fuel’s lubricity. That’s a major issue for modern Tier III and newer diesel engines, where the tolerances in injection pumps are so tight that simply holding an injector’s piston in your hand can warm and expand it enough so it will no longer fit in its barrel.
The American Society for Testing and Materials (ASTM) has a set of High Frequency Reciprocating Test Rig (HFRR) standards for diesel fuel additives, but testing is voluntary. According to ASTM standards, #1 or #2 diesel fuel test results should not exceed 460 microns of wear in HFRR tests. The lower an additive’s HFRR score, the better the product’s lubricity.
Some additives list their HFRR score in the very fine print on their label. Others post those results on their website. Others don’t submit their products to ASTM for testing and offer no verified independent results of their product’s performance.
It’s buyer beware when buying anti-gel additives for diesel fuel.
