| What are the consequences of having a dirty engine and what are the benefits gained from having a clean engine? Orica fuels and lubricants expert Schalk Bruwer explains: Why is engine cleansing important? SB: When you wash your dishes with no or too little detergent you will end up with a layer of dirt around the rim of the basin. Similarly, inside your car’s engine deposits will form if oil is not used to prevent deposits or clean up any deposits that had been formed previously. How can lubricants keep an engine clean? SB: Like dishwashing liquid quality oil such as Shell Helix contains the correct cleaning ingredients for the engine. The lubricant prevents deposits from forming. In addition it contains chemistry that actively and continuously lock away harmful dirt formed during combustion. This keeps oil channels open and moving parts free for best possible operation. What are the consequences of having a dirty engine? SB: Without cleansing, a car engine’s moving parts will be restricted. This can lead to inefficient operation, rough running, increased wear and engine damage which will reduce the value and reliability of the engine. This means more money is spent on fuel, oil and repairs, not to mention the associated inconvenience. What benefits can be expected from a clean engine? SB: With efficient cleansing the car’s engine will function at its optimum level in terms of fuel consumption and smooth running. The engine will also have that refreshed and rejuvenated just showered feeling. What is engine oil shear stability? SB: Strings of boiled spaghetti give a certain consistency to a pasta dish. If you take a pair of scissors and cut those into short pieces while boiling, the meal will be not be the right consistency. Similarly, the molecules in engine oil and added chemistry are selected to create the correct thickness of oil, which is also called viscosity. Achieving the correct viscosity when operating and during start-up is critically important to protect against wear and to improve efficiency. A combination of sharp edges (like piston rings) and high speeds will cut the molecules into shorter pieces leading to thinned out oil. The oil will then not have enough lubricity at operating conditions, which can lead to engine damage. How does Shell Helix help prevent engine oil shearing? Why Helix? SB: Shell Helix has been formulated with shear-resistant components that prevent the oil from thinning out, leaving it to do its job at operating temperatures and pressures. How do you know engine oil shearing is taking place? Can anything remedy it? SB: It is difficult to determine without doing an oil analysis. If unsure though, don’t waste any time. Get the right Shell Helix for your car and take it to someone to change the oil and filter. How important is the correct lubricant for the car’s engine? SB: If the engine is idling at about 900 rpm, each piston fires 7.5 times every second resulting in temperatures of more than 250°C. As a car pulls away, the engine speed increases to about 1800 rpm, meaning each piston is now firing 15 times every second before a higher gear is selected. The engine will now be reaching temperatures of more than 500°C. When reaching a destination after 30 minutes each piston would have: • fired at least 15,000 times. • travelled at least 4.64 km Remember that there are also the turning bearings, the rotational timing gear and the opening and closing valves that are aligned with the piston movements. Many lubricants will not be able to withstand these requirements. As more severe emission requirements are being introduced, the demand placed on the oil is continuously increasing. |
