by NowForThe5th on Sat May 24, 2014 8:29 am
IMHO a full synthetic is wasted in the V6 when you're doing 15,000km changes and unless operating in really severe conditions. A good quality mineral oil will do the job just fine, or perhaps go to a semi-synthetic.
This engine is a bit fussy about oil so you need to find one with just the right viscosity range to suit your conditions. It needs to be thin enough, when cold to get up to the top end quickly, but not too thin that it all drains out and leaves no protection at start-up. You'll know straight away if you get it wrong - it will rattle like crazy on a cold start until the oil pressure builds up. Even in Canberra I found a 5W was a little light in a straight mineral oil but semi-synthetic was ok.
Once hot, if you go too high on the viscosity rating the engine simply won't rev out. So a 50 is way too heavy and a 30, depending on the engine (age, condition etc.) may be too light. I found 40 to be ideal.
In Qld. I'd think that a 10W-40 semi-synthetic would probably be the best choice, 5W-40 if you're inland a bit and get cool mornings.
Brand too does make a difference. It all has to do with the length of the molecules and how they hang together. Some brands use different packages that will stay up the top and give some cushioning when cold. I found that Valvoline was the best for this.
Chris
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