Engine Oil For Your SV.
 

Engine oil for the Suzuki SV650 and SV1000, all years, all types.

The manufacturer recommends that you use a 10W40 oil that conforms to the API SF or SG standard, for the purposes of this piece this can be considered equivalent to the JASO MA standard. Either, (or possibly both), of those will be written on the container, if neither are there I recommend against using it*. It should be motorcycle specific engine oil*.

There are seemingly endless differing opinions on which oil you should use, but if you were to use a known brand**, motorcycle specific oil conforming to the above standards, all will be well.

A brief and entirely unscientific straw poll amongst a few knowledgeable persons suggested that most, (not all), would choose semi synthetic.

Check your oil level regularly and often, do not allow it to fall below the minimum level. Change the engine oil regularly, at least as often as the recommended intervals. Fit a new filter when specified too, there are many pattern filters available, their quality varies, I recommend using an original Suzuki filter unless you have an alternative the quality of which is known to be at least equivalent to the original Suzuki filter.

*There are those who have used other oils with success, but I'm not going to recommend that you do as there are far too many types of oil and variables in conditions of use to be able to give a definitive answer.
**From motorcycle shops in the UK this will likely include, but is not limited to; Castrol, Putoline, Rock Oil, Shell, Silkolene. The car accessory shop Halfords sell motorcycle specific 10W40 oil which is quite popular.