Recommendation On Engine Oil For M35 Vq25Det

[joshm35]

Meh I got castrol 0w30 fully.synthetic in mine just for that castrol comment earlier in thread. Booyeah

[KiwiRS4T]

I don't think Castrol qualifies as "real" synthetic. I was using Motul (well Nismo actually because I got it the same price) but have changed to Agip which seems to be a proper synthetic at a much cheaper price. Tried the Agip Racing 10W 60 which seemed to be fine but I want to try a lighter weight oil such as 5W40 so trying other Agip synthetics. I have an N1 oil pump so have heaps of pressure no matter what so relying on oil testing to tell me whats happening.

[scotty nm35]

I should get my sample test results back today Bob, $30 sounded pretty good to me for an oil sampling kit. How much were you getting the Agip for? I'm assuming you can buy that in bulk?

[Commsman]

I don't think Castrol qualifies as "real" synthetic.

Isn't there laws against false advertising? I can only assume if any manufacturer put the words "fully synthetic" on their label, it must meet certain standards. Or is there some leeway which allows someone to sell mineral based oil as "fully synthetic", or maybe only a % of the oil needs to be synthetic to qualify?? Maybe it's like McDonalds food having some "nutritional value", lol.

[iamhe77]

lol, they aren't falsely advertising. "Fully synthetic" has been deemed to be a minimum of 70% synthetic compounds. 100% synthetic is just that (which is why Nulon had to change their engine oil packaging).

For reference, I enquired about Anglomoil's "Roadmaster 500" as I have heard good things about it in the past and it is around $55 per 5L tin (yes, a tin, like in days gone by). Here is their response to my questions if you can be bothered reading a wall of text;

The Roadmaster 500 is a Group 3 based synthetic, I don't know of anyone making this type of oil from Group 5 base. Before the advent of Group 3 it was the norm to use a mixture of Group 4 and Group 5. The reason for this is that Group 4 is not a very good solvent for the additives and has limited seal swell characteristics. The Group 5 (Ester) was added at about 10% to enable the Group 4 to perform satisfactorily in these areas. This type of formulation was quite expensive to produce due to the cost of the base oils, the only product that comes to mind made this way is Mobil 1 due to Mobil being the worlds largest producer of Group 4 (Poly Alpha Olefin). The Group 3 base oil is a severely modified mineral oil with the same characteristics as Group 4 and has been determined that it can carry the title synthetic at a more economical price. This approach to most synthetic motor oils in the market is in the majority. There should be no problems with using E85 and Roadmaster 500. You can find a data sheet on our Web site www.anglomoil.com under Products, Petrol Engine Oils.

[KiwiRS4T]

I should get my sample test results back today Bob, $30 sounded pretty good to me for an oil sampling kit. How much were you getting the Agip for? I'm assuming you can buy that in bulk?

Agip varies from $55 to $70 per 5L (v Motul at about $70 for 2L) and the Agip I am trying next (5W 40) is $225 for 20L

[KiwiRS4T]

Meh I got castrol 0w30 fully.synthetic in mine just for that castrol comment earlier in thread. Booyeah

The other extreme from Castrol Edge 10W 60 which is almost definitely too thick. I was looking at 5w 30 weight but think its probably too light for my rB30 bottom end which is basically stock. It may be OK for a low mileage V6 in good nick for street use. Do you have an oil pressure and/or temp gauge?

[Commsman]

Can anyone back up my experience whereby an engine that was being serviced using one brand for it's entire life (bar what was in it from the factory), & then when changing oil brands after ~180K the engine immediately starts using oil & then the rings go a short time (~10k) later.

This was in my work vehicle & was serviced by Rep##, first at one location then transferred to another. It was suggested to me that the different detergents (or other additives) were to blame - one built up over the years & then new oil removed them. Does this sound feasible? If so, it leads me to think the best thing is to regularly swap brands or pick one & stick with it forever.

I'm using an oil in my M35 that I don't particularly want to continue using (too expensive for what it is & shall remain nameless), but it's been the only oil used for the last 70K as the owner before me only used this one. Given my experience, I'm reluctant to change brands in case there is some truth to the above. My car performs well although the viscosity is a bit heavier than what most would use, but I have no comparison since it's always the same oil... Thoughts?

[iamhe77]

May have had something to do with the quality of the second oil in the work car?

I know that some of the oils that I have tried in the Magna (265000kms) have had very different results as to "usage". Most of these were the same weight as well.

eg, Nulon "synthetic" 10w40 (dropped after 6000kms due to ticking) - 5L went in and only 3 1/4L came out. Valvoline Synpower "synthetic" 5w40 (full 10,000kms) - 5L went in and ~4.8L came out. Mobil 1 (5w50), Amsoil (10w40) and Motul 8100 (5w40) - 5L in and 5L out after 10,000kms.

Do you mean that the sludge built up when using the first type of oil and then the detergents from the second type cleaned it all out which caused the engine to use more oil?

I had my Stag for quite a while and tried a number of different oils (Amsoil, Shell, Mobil, Motul, Redline, Valvoline, RP, Penrite, Neo)... all different quality and very different detergents/additives. At the 220,000km service, all 5L of Sougi came out. Take from that what you will

[Commsman]

May have had something to do with the quality of the second oil in the work car?

Do you mean that the sludge built up when using the first type of oil and then the detergents from the second type cleaned it all out which caused the engine to use more oil?

I had my Stag for quite a while and tried a number of different oils (Amsoil, Shell, Mobil, Motul, Redline, Valvoline, RP, Penrite, Neo)... all different quality and very different detergents/additives. At the 220,000km service, all 5L of Sougi came out. Take from that what you will

Very interesting. It appears you have used lots of different oils so probably never kept the same one in for more than (say) 5 oil changes. I wonder if you would have the same result if you used just one type for 18 - 20 changes & then swapped brands?

TBO I have no idea what caused the oil consumption in the work car, other than it happened at the same time as I changed mechanics & they use a different brand. Maybe it was just a coincidence, but I have a hard time believing that. Then, only a short time later, the rings were completely gone & the engine was smoking like a James Bond smokescreen, lol.

My M35 doesn't use any oil (well, maybe a negligible amount), but am a little concerned that a change of brands will cause more harm than good. I don't know, is 70-80K long enough for 'build up' to occur. I had the valve cover off yesterday & it was all clean in there. Maybe I should give another brand a try....

[iamhe77]

Yes, I used 300v Chrono for more than 5 consecutive changes early on and then Sougi towards the end of my ownership for 4 changes (40,000kms).

I don't have the pic on this pc, but when I took the valve cover off (~205,000km mark), it was clean as a whistle...

[m35stagea]

I cant get a good reading on my dipstick.

Oil / filter swap what capacity is it 4.5?

[Daleo]

I use around 5.4lt in mine when I do oil & filter. I don't think 5 litres is quite enough.

The dipstick reading is best taken first thing in the morning after being stopped overnight on a flat surface.

[Commsman]

If it is well drained with a new filter, the entire contents of a 5L container is perfect.

[scotty nm35]

I don't even check the dipstick anymore, I just dump the 5L in with a fresh filter.

[PN-Mad]

I check because my oil comes in 20 litre drums

But yeah- 5liters, and slightly over full, like Dale said, is fine too. Good for the track.

[scotty nm35]

Good for the track, lol.

It's not an RB phag.

[PN-Mad]

Its what all the cool kids are doin.....

if you can give it 5-10% more oil without having drag issues, why not?

Won't help you but - Mr 136 degree oil.