Thursday, August 09, 2012 - 05:43 pm, by: Lyall Jeanneret(2piesnosauce)
...actually it doesn't blow smoke every time I start it, just every couple of starts or so. It was the worst after a long drive from brisbane to toowoomba, then after a little cool down... a poof of blue smoke, not real big but enough for me to be a little concerned.
Friday, August 10, 2012 - 11:32 am, by: David Henderson(Hendo)
I haven't used m1 but it looks good on paper (virgin oil analysis) and I've heard it shears badly (thins to a 30 weight after 1000ks). I've also heard in recent years it has changed from PAO based (grp IV syn) to a group 3 based oil (which is cheaper)
Lyall / Andrew, whats your oil consumption per OCI?
Friday, August 10, 2012 - 06:55 pm, by: Lyall Jeanneret(2piesnosauce)
I don't know my oil consumption yet, only had the car a couple of days. A friend of mine who is a mechanic by trade reckons to put some good oil in and give the car a good run, as the car has only gone 139,000kms, it may have sat around a bit which I think it did, and wasn't given the boot much... according to previous owner.
Saturday, August 11, 2012 - 09:22 am, by: David Henderson(Hendo)
Jonny, Mobil 1 15w50 won't shear nearly as much as a 0w40 because it doesn't use as many VIIs (viscosity index improvers) which are used to allow an oil to span a wide weight range- having a low pour point (0w is about -40 deg) and a high operating viscosity (40, 50)
In the case of a full syn like the 15w50 it probably doesn't have any VIIs so it won't shear out of grade over the oci. It's a well speced oil for our application, if you can afford it!
I couldn't believe the 25w70 in a 1jz either, too thick an oil will just pop the 75psi bypass on the oil pump and starve the top end. I'd hate to see the wear numbers on that oil. However if an engine was built with loose bearing clearances that oil would be fine. I think the ideal is 75 psi at redline or 10psi/1000 rpm. Any more than this, the oil is too thick and the flow is restricted. And it's flow which matters, not just pressure