Engine Oil: what's best?

[an observer]

Supercheap have the penrite 10 40 on special, so picked up some for the next service.

Currently using a 10 40 semi synthetic, so not expecting to notice any difference in the short term.

[an observer]

Oil changed despite mechanics objections, saying it will develop oil leaks on full synthetic.

Not sure what to think about that, but guess ill find out soon enough.

[leadfoot6]

In this post dealing with 380/6g75 engines:

https://www.aussiemagna.com/forums/sh...=1#post1641390

Madmagna has suggested Gulf Western Syn X 3000.

It is on special at the seemingly very good price of $19.99 until 29 March at Supercheap:

https://www.supercheapauto.com.au/p/...re/283732.html

The limited number of reviews that I have seen are mostly positive.

My transplanted 6g75 engine in my TL AWD is approaching 6 months from time of installation.

I might give the GW product a try later in the year.

It is semi-synthetic, as opposed to being termed a full-synthetic oil, but I had been using Nulon 10W40 semi-synthetic for a few years in my 6g74 before it was replaced by the 6g75 without any significant problems other than some leaks from the rocker cover gaskets, which was not unexpected @190,000km at time of replacement.

At approximately only 20,000km total travelled from factory new on my new engine(sitting in a warehouse for a lot of years until it was installed by a previous customer of MitsFix), I am not expecting any problems at all.

P.S. The new engine install and all other work carried out by MitsFix is still all 100%.

I picked up two 5l containers whilst still on special.

It will be a few months before I need to change the oil, but I will report when completed.

In a few months my transplanted 380 engine will have been in place for 12 months.

I have purchased the Gulf Western Syn X 3000 semi synthetic that I plan to use.

After reading some of the anecdotal evidence as noted at "BITOG", and other forums, I hesitate to use a full synthetic oil.....

.....just in case.

I am not tempted to do so purely to obtain a marginal decrease in fuel consumption as a result of using a full synthetic oil.

[an observer]

It has been run on semi synthetic for the past five years.

If leaks develop on full synthetic and are intolerable it will be switched back.

Wait and see.