We will look at multigrade oils, engine oils (two and four stroke), gear oils, transmission oils and two stroke outboard oils.
Overview
Oil is the lifeblood of any vehicle; while it’s main job is to lubricate moving parts, it also cleans, inhibits corrosion (stops rust) and cools the engine by taking heat away from the moving parts.
Engine Oils
Modern engines require a much higher grade of engine oil than older engines; this is because of higher temperatures, higher loads, higher rpm’s, increased servicing intervals and reduced clearances.
There are many grades and viscosities available and it can be hard to choose the right engine oil for your vehicle. Older vehicles tend to specify thicker mineral based oils (e.g. 15W40), and newer vehicle tends to specify thinner semi-synthetic or full synthetic oils such as 10W30 but you should always check your owner’s manual or ask your mechanic what oil your vehicle needs.
Two & Four-Stroke Engine Oils
A two-stroke engine premixes the oil with the fuel (before entering the engine) and this is used to lubricate the engine before being burnt in the cylinders, whereas four-strokes have engine oil separate from the fuel, the oil is pumped around the engine lubricating it then draining back to the sump to be recirculated again and again.
Because of these fundamental differences in 2 and 4 stroke engines, the oils required are very different and should never be used in the wrong application.
Gear Oils
There are many types of gearbox and differential designs, e.g. bevel cut gears, hypoid gears and limited slip differentials and they are used in many different applications.
The right gear oil for the right gearbox or differential is essential to ensure reliability and long service life. Most gear oils are also multigrade but at much higher viscosities (e.g. 75W90, LS140), this is because of the loads and designs of these units. Gear oils also need to be replaced at specified intervals due to internal components wearing during operation and minute metal particles being picked up by the oil.
Transmission Oils
Automatic transmission oils are coloured red for easy identification and are very thin high-pressure oils. This is because an automatic transmission actually uses the fluid to transmit drive from the engine to the gearbox and there are also very fine tolerances in the rest of the transmission.
There are also many grades available such as Dextron I, II and III, LE and Mercon. Again consult your owner’s manual or mechanic for the right grade for your vehicle. This oil is also used in power steering systems.
If you are unsure of any of your oil needs please get in touch.
