What happens to the wax in diesel when it is cooled?

All modern diesel contains wax. It’s considered an important component because of its high cetane value. However, wax in diesel reacts when it’s in a cold environment. Watch what happens when we put a sample of fuel in cold water:

Why does wax in diesel cause issues?

Under normal conditions the paraffin wax added to diesel improves viscosity and lubrication. However, when temperatures begin to fall, this paraffin wax thickens and turns into a cloudy mixture. This point is known as a fuel’s ‘cloud point’.

If left the problem can clog fuel filters and solidify to the point where the fuel no longer flows and renders your engine useless.

In 2015, the BBC launched an investigation into the effects of cold temperatures on diesel fuel after receiving a number of complaints about Hyundai’s ix35 in Scotland. The BBC Watchdog investigation discovered that some ix35 engines were breaking down after the fuel filters became blocked with wax.

According to Hyundai, between September 2013 to April 2015 there were 14,845 reported incidents of blocked diesel filters. Not all of these reports relate to cold temperatures but it is further evidence that modern engines are sensitive to contaminated fuel.

The solution

The solution is to install a Diesel Defence fuel polishing unit alongside our diesel and oil heaters:

• Diesel Defence fuel polishers: Diesel Defence combines filtration and circulation to keep your fuel clean. The polishers circulate the diesel to prevent pockets of dirty fuel or water collecting in stagnant parts of your tank. Diesel Defence circulates your stored fuel up to seven times before it passes to the day tank or your generators.
• HOTSTART’s diesel and engine oil pan heaters: these are an ideal solution to heat multiple types of liquid: water, liquid lube oil, hydraulic fluid, antifreeze as well as petroleum. This assists engine starting by pumping warm oil instantly to the critical wear points in the engine, reducing engine wear as well as allowing easier starts which therefore prolong battery life.