Summer-grade fuel left in tanks over winter can start to ‘wax’ as a result of cold weather. Winter-grade fuel is gas oil that has been enhanced with an additive that lower the temperature where fuel would normally begin to wax. This helps to protect your fuel and machinery, even in freezing temperatures, the distribution of winter-grade fuel in the UK typically begins in November and ends in March. You can use winter-grade fuel all year round, however, the summer alternative should only be used during warmer periods.
All diesel fuel contains paraffins, it is the paraffin content that gives diesel the high cetane number that makes for efficient combustion.
When gas oil is cooled, the paraffin molecules start to form crystals and solidify, if the temperature is low enough, larger crystals can form and cause filters to become blocked.
In severe cases, the 'wax' may completely block the pipes, when this happened the engine will no longer receive the fuel needed to run it.
An indicator that the paraffins have crystallised in your gas oil may appear cloudy.
Winter fuel can be used all year round as it is more resistant to cold (-12°C CFPP min), meaning it can be used throughout all seasons.
Fuel certified for use during the summer period is only fit for use during these months (-4°C CFPP min) as it has limited resistance to cold.
Exposure to wind can accelerate heat loss and reduce the temperature of the fuel, so provide shelter and protection for tanks, pipes, pumps, and vehicles to prevent them from cooling quickly when exposed to wind and decrease the likelihood of wax
crystals forming.
In the event, that you have summer-grade fuel remaining in the tank, please inform the sales team when ordering as we are able to supply additives to improve the winter protection. If you only need one top-up during the year, it is better to order winter-grade fuel as this can be used throughout the year. For the latest commercial fuel or gas oil prices please get in touch and our dedicated team will be happy to arrange a personal quote. Call our team on 016974 76575 or email us at adminoffice@allanstobart.co.uk.
