There are two different overall types of oil for 4-stroke engines: Semi-synthetic and full-synthetic. Semi-synthetic is typically best suited to standard-yielding machines, where full-synthetic is most often suitable for engines that take a lot of turns and therefore have a greater need for efficient lubrication.
Next, 4-stroke oil has another parameter to consider, namely the viscosity of cold and hot use. So when 10w-40 stands on a can of oil, the first number indicates viscosity in cold use (cold weather or cold engine), therefore 'W' also stands for 'Winter', and the number after the dash then indicates viscosity in hot use ( hot weather or hot engine). In the case of 4-stroke oil, there are also so-called APIs, one must be 100% certain that the engine needs. APIs are basically additives that have an impact on life, lubricity and other properties. Always check carefully what API requirements / needs exactly your engine has before pouring new oil.
We sell 4-stroke oil from manufacturers such as Galp, Castrol, Malossi, Motul and Selenia. If you are unsure which oil is best for your particular machine, we recommend that you check your manual or ask your local dealer.