Engine oils have a critical role to play in the workings of a 2-stroke engine and without a good quality engine oil, your engine may only last a very short period of time.
Many think that engine oil only has one job: the lubrication of the moving parts. But they actually do a lot more. When you consider that they’re only added to your fuel in a ratio of 1 part oil to 50 parts fuel, you can understand why we recommend using premium oils; it’s a lot to ask for such a small concentration!
One of the oil’s jobs is to minimise and protect against harmful deposits coking up in the exhaust and slowing the fast flow of exhaust gases from leaving the engine. It also needs to leave the combustion chamber and piston clean so the engine can “suck, squeeze, bang and blow” in the most efficient way possible. After all, a clean engine will more likely produce more power! Find out more about how a 2-stroke engine works here.
When you see the moving components of the engines, you can see why a good quality engine oil is required. As these components can move at a rapid rate of up to 15,000 rpm, the oils are used to minimise wear to the engine by providing lubrication to moving parts.
Learn how a STIHL 2-MIX Engine works:
The oil also needs to be clean burning so that the spark plug continues to spark over and over again, and to have a long working life. The spark plug plays an important role in the engine as it ignites the fuel and oil mix so it’s important to make sure it’s protected.
2-stroke engine oils also have to work across a range of engine types with large variances in temperature and rpm. Petrol hedge trimmers operate with a relatively low 5000 rpm and a temperature of around 150 degrees at the spark plug, while chainsaws operate with an rpm of up to 15,000 and temperatures of 300 degrees at the spark plug.
Engine oil quality also plays a big part in preventing carbon build-up around the valves of 4-MIX petrol engines. It’s important to use STIHL HP Super or HP Ultra oil with STIHL 4-MIX engines to reduce the likelihood of poor running behaviour and the need for a trip to a servicing STIHL dealer.
The engine oils also have to protect the engine from corrosion and keep the crank case clean (the lower half of the engine) to allow the fuel mix to circulate and components to move freely. That’s why we have spent years developing and refining STIHL engine oils to suit all applications, from consumer tools through to professional use.
We have three different types of oils available in the range; STIHL HP, HP Super (Semi-synthetic, low smoke) and STIHL HP Ultra (Fully Synthetic), a selection that we like to call our good, better and best offering!
STIHL oils are formulated with a base oil and then have special additives on top to give them certain beneficial properties. The base oil is a mineral oil in the case of HP and a fully synthetic oil in HP Ultra.
These special additives give the oil a certain viscosity or lubricity, as well as giving anti-wear properties and reducing carbon deposits and corrosion. In STIHL HP Super, the additive polyisobutene leads to reduced smoke from the exhaust. In the case of HP Ultra, the synthetic additives are biodegradable.
All of these STIHL oils can be used with E10 fuel. As E10 fuel has a short shelf life, we do recommend mixing 2-stroke fuel in small quantities to avoid wasting engine oil.
You can see the difference in the piston after 500 running hours between STIHL oils, and a conventional, poor-quality oil. As you can see, an engine using HP Ultra looks almost new!
If you don’t want to worry about mixing your own fuel, we offer our own pre-mixed, premium alkylate fuel, STIHL MotoMix. STIHL MotoMix is long lasting, high-quality fuel combined with HP Ultra oil for best engine performance.
You can find out more about STIHL engine oils at your nearest STIHL Approved Dealer, or ask us any questions in the comments below.