yet another Oil question

[Badgerman]

Hi everyone. This is my first post here, so I would like to to say hello.

Now my problems.
I have Holden Commodore VT II 3.8 V6. It has just above 200kkm on clock, and it is a good time to change oil and maybe few more things. According to Service Manual, I should use 10W-30 oil (SJ GF2). Alternatives are 15W40 or 20W50 with SG, SH or SJ parameter. I preffer to use full synthetic (previous owner has done that and said that I should continue this). It is not so easy to find good oil with those parameters.

I have found Mobil 1 - 10W30 Full Syntetic, but seller wants AU$96 per 5.7L. I have found also few more, that initially seems ok:
Lucas Oils 10128 Synthetic High Performance Motor Oil 10W-30, 5 L It has correct viscosity, and SJ norm, but I do not know about this manufacturer. This is for about AU$76

next one is Castrol Edge Engine Oil - 10W-30 5L for only AU$60, but I am not sure about its parameters such like API SN/CF (instead SJ) or ILSAC GF-5 (instead GF-2).

same here: CASTROL ENGINE OIL GTX MODERN 10W30 5L for AU$40. It is not listed what kind of oil it is.

I have found also this one Gulf Western Oil Premium Energy 10W30 6LT Energy Oil for only AU$38, but this is a suspicious price. I am not sure is it full or semi synthetic. Also company is not well known.

I do not have any idea why all manufacturers recommend 5W30 oils. There is nothing like that in car's manual.

So here are my questions:
1. Wchich oil from that above?
2. Maybe other (but I preffer still full synth)?
3. I have found that two lenght of oil filter is listed for my car -79mm and 129mm. Currently I have shorter one. Both cost same money. Are there any advantages to install longer one ? Any contraindications?
4. K&N filters (white series) are fine, or I should pick other ?
5. What are change intervals for spark plugs, spark wires, oil (when synthetic and car runs in City only), oil filter and fuel filter?
6. Is there everything more that I should check/replace (I mean periodic changes, not worned elements )
7. How can I cancel "Service 200000" from my clock ?

 

[The1]

have you had any oil tests done? Are you monitoring oil pressure to see which oil provides correct pressure? If not, stick to what's in the owners manual.

 

[Badgerman]

have you had any oil tests done? Are you monitoring oil pressure to see which oil provides correct pressure? If not, stick to what's in the owners manual.

No, I have not. Well manual says what is above. I concern about that norms SJ and GF-2 because no oil is produced according to them anymore. In other threads I have read that people use 20W50

I have found that oil with that viscosity:
Royal Purple Motor Oil - 5 Litre, 20W-50 for AU$90
Penrite MC-4 V Twin Motorcycle Oil - 20W-50 4 Litre for AU$70 , but I am not sure if that is suitable
Castrol GTX Engine Oil - 20W-50, 5 Litre for AU$30, but is it still full synthetic ?

 

[gossie]

This info. may or may not help you.

My Daughter has had a VT now for over 10 years with now close to 300,000 on the clock, and it runs well, VERY well.
I have changed the oil for her twice a year using Magnatec 15-40, including the oil filter each time, normally RYCO. Any known filter is okay........We buy buy bulk oil when on special. (My VE uses 5-30 as per the books)
I change her plugs, an easy job on an Ecotec about every 3? years, and take off the service warning using the instructions in her books......Sorry, I can't remember them, so check your books.

GTX is a mineral oil. Magnatec is a semi synthetic oil.

When you decide on the oil you wish to use, purchase the one that is as per the books in letters/numbers or beyond.

 

[Badgerman]

This info. may or may not help you.

My Daughter has had a VT now for over 10 years with now close to 300,000 on the clock, and it runs well, VERY well.
I have changed the oil for her twice a year using Magnatec 15-40, including the oil filter each time, normally RYCO. Any known filter is okay........We buy buy bulk oil when on special. (My VE uses 5-30 as per the books)
I change her plugs, an easy job on an Ecotec about every 3? years, and take off the service warning using the instructions in her books......Sorry, I can't remember them, so check your books.

GTX is a mineral oil. Magnatec is a semi synthetic oil.

When you decide on the oil you wish to use, purchase the one that is as per the books in letters/numbers or beyond.

Thank you for your answers. Magnatec is synthetic ?

 

[gossie]

Thank you for your answers. Magnatec is synthetic ?

The MAGNATEC I use is semi synthetic. It's the fuel saver version. But I believe there is a synthetic version available now.

 

[Commo Baba]

Reckon you're over thinking it way too much, but I wouldn't be using 'V twin Motorcycle' oil !? Your car's engine is not a V twin !

Yes the book does say 10W30 but something a bit higher won't hurt, (Like the 15w40 of the guy posted above). The shops have books or touchscreens in them usually for reference.

I just get the best I can afford on the day when I go to the shop. I've never even thought about "SJ GF2".

BTW 'Gulf Western' is a common product. Maybe they just made it over to that side ?

 

[EYY]

Hpr10 comes on special regularly at most of the big auto stores, and would be my pick if you want to use a synthetic.

I put castrol gtx and valvoline xld in my ecotec for over 100,000 hard k's and never had a problem. The oil's cheap and since these engines are a pre 90's design and have roller lifters, they'll run well on anything as long as you keep it clean.

 

[devilly]

over 400,000 on my clock,the only one i will use now is 20w-50w. in my book recommends 20w-50w holden's recommend 15w-40w.

but after putting and oil pressure gauge on my car and trying ever oil viscosity.

i found 20w-50w to be the best so far

 

[The1]

i was using 15/50 mobil 1 for years, had to buy from the disty, but they no longer carry it, only in 20L drums, i had done oil tests for years and found 15/50 spot on from mobil 1, the cold start oil pressure and summer hot oil pressure was great, down to idle sitting at 55psi, i changed to penrite fully synthetic i first tried HPR 10 10/50w, but hot oil pressure at idle was down to 45psi, i moved upto HPR15 15/60w and it's the same as mobil 1 15/50, the datasheets are pretty close to, the oil tests look the same as well. HTHS is pretty good.

Here was my old comparison.
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