The Mitsubishi Pajero Owners Club®

jenjenoz

Hi I have just changed my Engine oil on my 2003 3.2 did.I realized later that its Castrol MAGNATEC 10w-40 A3/B4 Engine Oil and its fully Synthetic.Is this ok to run as I am driving to Turkey.Or should I replace with 10/40 semi?.Tia.

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iam_TJ · Posted: Sun Mar 19, 2023 23:22 Post subject:

According to page 9.4 of the owner handbook:

"Selection of engine oil (diesel-powered vehicle)"

ACEA classification: "For service B1, B2, B3 or B4"
API classification: "For service CD" or higher

And in the humorously titled "Diedel-powered vehicle" graph:

SAE 30 == 0 to 40C
SAE 20W-40 == -10 to 50C+
SAE 15W-40 == -15 tp 50C+
SAE 10W-30 == -20 to 40C
SAE 5W-30 ==-40+ to 10C

There's no mention of mineral, semi or fully synthetic.

Milner's for that model lists semi-synthetic engine oil:

https://www.milneroffroad.com/mitsubishi-shogun-3-door-3.2-diesel-from-2000-to-2007-v68s/catalogue/engine-service-kits-oil-enfk-en

Halfords guide might help understand whether it is important:

jenjenoz · Posted: Sun Mar 19, 2023 23:49 Post subject:

Thanks.I read somewhere that it was something to do with not allowing the piston rings to seal better or something.I don't want to knacker something for the sake of draining this and using semi.The engine will be going for hours on motorways when I set off.

icehawk · Posted: Fri Mar 24, 2023 12:40 Post subject:

Dont worry,i ran my mk2 on fuchs synthetic oil for over 120,000 miles and the engine in total had done 0ver 220,000 miles when i scraped it down to rust,engine still ran sweet,been using same oil in my 2005 shogun for around 60,000 miles with a total 0f 211,000 and again engine runs as sweet as a nut.

jenjenoz · Posted: Fri Mar 24, 2023 13:31 Post subject:

Thanks for the reply. I have now changed the oil to semi.I suppose I could top up with the fully synthetic if needs must now then.

assassin · Posted: Fri Mar 31, 2023 3:39 Post subject:

Problems arise with the oil film thickness and moving from pure mineral to pure synthetic would kill many older engines as the rings and piston bottom would scuff in the bore and kill the engine, so they introduced semi synthetic which was around half mineral additives and around half synthetic additives and in all cases the mineral content is the lubricating content in mineral, semi, and full synthetic oils irrespective of make and the additives are there solely to protect the mineral lubricating element and nothing more.

If your engine is in good condition then swapping from a semi to full synthetic will be no problem and the problems come with switching from mineral to full synthetic as full synthetic is much slippier and full mineral allows components to gum up and with its thicker film and gumming things like the piston rings and oil control ring work to the thicker film thickness and gumming restricted their ability to move in and out and a switch to full synthetic with its nuch thinner film thickness means the piston rings need to come out more to fill the gap and the gumming on the rings prevents this and the gap is never filled leading to loss of compression.

To be certain you can add a cleaner to your engine oil before you change it from semi to full synthetic and it must be the type to remove varnish and gum deposits, follow the instructions on the cleaner and swap to full synthetic as the rings wont be gumming up.

jenjenoz · Posted: Fri Mar 31, 2023 7:22 Post subject:

Thanks for the reply.I have had the car around 4 years and as far as I know I have used 10/40 semi each year I have changed the oil.I ran this with 10/40 full synthetic for about 10 miles and changed back to 10/40 semi.The oil was already black in the short time I used it,is this normal?.

assassin · Posted: Tue Apr 04, 2023 3:20 Post subject:

It will be in a diesel engine as its the soot deposits. Ignore the halfords guides as they are generic and wrong on so many levels.