[kwiksix]

i know this topic has been done before, but i just bought some oil (castrol R4 superbike) and it has a 5w40 weight, where the bike manual recommends 10w40. its supposed to be the best synthetic motorcycle oil castrol has, but it only comes in 5w40. im just wondering if i should return it or if it will still be ok. it says its good for all 4 stroke motorcycles. i know the 5 is for a lower temp. and it is a thinner oil, but why would castrol make only that one kind?

 

[kwiksix]

well, does anybody know if 5w40 is ok for the bike?
thanx.

 

[windows98]

i guess you can use it.... it really depend on where you live? or what i mean the weather condition you'll goin to use it.

 

[UniSonic23]

Oh BS about weather conditions...
The main factor is whether it has those anti slip additives in it.... if it does than you can't use it because you have a wet clutch... and it will cause it to .... well slip...
I can't tell you if it has the anti slip shit in it i just know 10w-40 doesn't....

 

[kwiksix]

its bike oil for sportbikes, im sure its compatible with the wet clutch. which oil do you use.

 

[rraiderr]

http://motorcycleinfo.calsci.com/Oils1.html

 

[Dr.Demento]

I used Castrol GTX 10/40 for the breakin period and first two changes then switched to AMSOIL (not MC specific). Any 40W or better oil generally does not have friction modifiers. That means oil like 10W30 or 5W20 do (which we are not supposed to use anyway). I was going to use either the AMSOIL or Rotella T-Sync 5W40. They are automotive oils but very high quality. If you use a 20W50 then you definately do not have to worry about friction modifiers being present. At least almost every bottle of 10W40 or 20W50 I've seen does not have the 'energy conserving' on the seal.