What Oil?

I'm sure this topic has come up before.
What oil do you all use?
When I first got my GS500E the Watford Suzuki dealer gave me Mobil Extra 4T when asked for suitable oil for a service. I read that car oil should not be used due to the slippery additives that wouldn't be too good for the wet clutch. I also thought the api rating was a standard not only for the oil and useage but also the additives. The handbook recommended api SG. and so does the handbook for theSV. The oil used in my Honda Civic car is api SL and so is the Mobil Extra 4T, Why, and what is the difference if any?
I thought I had enough Mobil left to do my SV but was short so went to Halfords to buy some more. Of course sod's sets in here as they had none but they did have Castrol 4T which is api SG rated so I topped up with this.
I noticed that Halfords do api SG motorcycle oil that comes in 5 litre cans not 4 litre. Now 25% extra is not to be sneezed at so tell me why I shouldn't us it if it meets all the Japanese factory standards etc as it says on the can?

I'm not a mechanic and won't claim to have tried all types, but I can give a quick gist of what has been said and the bits I've learnt.

The claim is that for it to be ok with wet clutches it should be rated with JASO MA. The halfords motorcycle oil doesn't actually have that.

As for the other ratings, they're to do with the quality of the refinement. Suzuki recommend SG or whatever as a good minimum level, most oil you would buy in this country would far exceed that quality.

Generally the preferrence seems to be towards sem-synth, because it is a little easier to top up with either mineral or fully synth if you really had to.

I use Castrol 4T, probably overkill on the SV, but it was quite cheap in halfords and I was bored of looking at oil.

Thanks for that Carsick.
If the JASO MA standard is met does it have to be stated on the tin?
The Mobil 4T doesn't and is semi synthetic, the Castrol GP does and isn't semi/fully synthetic.
So many permutations of oil, all supposed to do the same thing and most trying to make us spend more than we need to.
If the Castrol GP was overkill for the SV then the Halfords oil should be OK?

I see no reason why they would put their oil through the testing for a specification and not list it on the bottle.
The Castrol GP 4T is fully synthetic, but there are some odd things with the names of the Castrol GP oils, I think just branding changes for difference countries.
I personally think that fully synth tends towards overkill on the SV, I may be wrong. I know people who do use the halfords oil, but I avoid it because it doesn't have the JASO MA mark.

I agree, most of the differences in oil tend to be to make us spend more because it says something different on the bottle.

So if Castrol GP 4T is fully synthetic why don't they say so on the can?
Castrol are no different than the others in bragging about their product.
All I know is that I spent the same amopunt of money on 4 litres of oil as I could have on 5 litres all because it was Castrol and yet if I followed what was said on the can I should have bought Halfords, but?????

I don't know why it doesn't say, it's probably got more to do with branding than any technical reason.

Thanks for your input Carsick.
We need somebody who knows who is independent of the oil companies who will give an honest reply.

I tend to use semi-synthetic oils in the zx6, Kwak uk recommend this, so can't see the point in spending twice as much on fully Synth. I Use Silkolone oils , but cannot remember which exact one.

You need to stick with oil thats specifically designed for bike use as these don't contain friction modifiers that can play havoc with wet clutches...

Fully synth is probably overkill, I use Total semi-synth in my MiniTwin race bike...

Dazzler and ZXman, would you use Halfords motorcycle oil?
It is specially designed for wet clutches and meets the api SG rating. And it's cheaper.
My original post was to find the cheapest oil that meets the spec for SV use and would do the job well.