hi all, will this oil be ok for my elxr8?? it says 15w-40 in the manual but i went to repco and the closest they have to that is 10w-40. thanks

How many k's mate?
I'm running Magnatec in my AU and the oil pressure drops into the red on a hot day, especially with the AC on, it's done 240k's.
Try it and see how it goes.

its done just over 100,000km. i might have a look around town 2morow and see if i can find some 15w40 cos i dont wana find ive got low oil pressure and have to spend more money as i just spent bout $1300 on it last week.

well after doing some reading it seems that 10w40 would be the same as 15w40 when at normal operating temp. 10w40 would just be a bit thiner when cold. will this cause low oil pressure on start up??

the 10 or 15 is the grade when at 0 degrees. in australia you don't really need to worry about that part of it.

if you don't mind spending the extra i would fully recommend using a full synthetic like you suggested.

i've used for many years shell helix ultra with no worries at all. i reckon that may even be 5/40. thinner on startup is good as it gets around engine quicker. much more critical on todays modern engines. my ef xr6 had 230 odd k's when i bought it, changed it over to helix ultra and sold it on 293k's and it never missed a beat and oil pressure never dropped much below 1/2. (a/c @ idle). not low k's but i still use synthetic. i believe in only going thicker if the signs are that it needs it. not just because it may have high km's. in your case, not an issue.

since buying the ba i now use mobil 1 10/30 in it as shell don't do a 30 in full synthetic.

i'm not starting a this oil is better than this oil thread. all i suggest is whatever you choose, if you are happy with it then stick with it.