Modern diesel vehicle engines need the correct oil to work as the manufacturer designed.

Use the wrong oil and you may face some expensive repairs.

Oil is not just for lubrication. It also cleans, inhibits corrosion, improves sealing and cools the engine. It also has a direct influence on the exhaust emissions.

Modern exhaust system are designed for use with specified oil. The wrong grade will cause these to “clog’ due to excessive soot build up. These are expensive items to replace, so you need to ensure you use the correct oil.


SO WHAT IS A …CAT (CATALYTIC) converter, a DPF (DIESEL PARTICULATE FILTER), and EGR (Exhaust Gas Recycling) system and a SCR (Selective Catalytic Reduction) system??

These systems are all designed to improve exhaust emissions and reduce air pollution.


A Catalytic converter (CAT) is a device mounted in the exhaust system to convert toxic by-products of combustion into less toxic products by way of chemical reaction using a catalyst. Most vehicles use a 3 way converter as they convert the three main pollutants; carbon monoxide, unburned hydro-carbons and oxides of nitrogen. The first two undergo catalytic combustion and the third is reduced back to nitrogen.


Diesel Particulate Filters (DPF) are fitted to the exhaust systems on diesel vehicles to remove soot from the exhaust gas. They do this by storing the soot and then burning it. This is called “regeneration” and takes place at temperatures in the exhaust normally obtained during open road driving.


Exhaust Gas Recycling (EGR) is very common in diesel engines. It is designed to recirculate some of the exhaust gas that would normally go out through the exhaust, back into the combustion chamber for a second burning which lowers the exhaust emissions.


Selective Catalytic Reduction (SCR) systems inject a urea base product called ADBLUE in controlled amounts into the exhaust system. ADBLUE is not added to the fuel but stored in a separate tank. The head in the exhaust system converts the urea into ammonia (NH3) and carbon dioxide (CO2). In the chemical-catalytic process that follows, the nitrogen gas is a natural ingredient in the air we breathe. Any possible residues of ammonia are removed in the integrated clean-up catalytic converter.


NOTE: Adblue must NOT be added to diesel fuel. It WILL cause serious and expensive failure of fuel system components including injectors, pumps, fuel lines, fuel tanks.