Vq25Det Oil Thread - So The Major Repairs Thread Isnt Derailed

[MrStabby]

Jetwreck said:

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I'm with you Duncan about the 40 figure.....it's the 5W30 or even worse the 0W30 figure in Australia that does not suit this motor. That oil figure is for the Japanese domestic market and as this car was only released into the Japanese market things will be different. e.g. 100 octane fuel, Temperature, Humidity....and the big daddy.....Snow! They also recommend plugs with a heat sig of 5....I run 7's

"but thicker oils protect better at high temperatures/stresses" This statement only reenforces my argument for not using a 5W30 oil......We have a high boost motor(even in standard form) pushing 2T through a gearbox that sucks over 1/3 of the power and for 5-6 months of the year in the eastern states we can quite easily hit 30-40 degree's.

The Grade of oil also plays a significant part in motor wear with this thing.......Going to Bob the mechanic and getting him to do an oil change with a $5 filter and $20 can only lead to a bad ending. But what do I know.......it's not like I work on these things every other weekend.

Adam - Test the IIRC recommended oil! Go crank some more boost into the motor and take if for a thrash......then put 10W40 in and do the same thing. Let me know what you come up with..... also test it mid summer!

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I will probably test the Valvoline 5W-40 full synth i have in it at the moment at 10,000kms, and I will try a ?W-30 after that and also test it at 10k too. Will only be stock motor on stock boost tho. My Stag is a daily and the GTR is the one for thrashing. If you're running a non-standard motor, then the factory oil recommendation no longer applies. I don't recall OP mentioning he was non-standard, but even even on a mild tune I still believe a full syn 0W-40 should be an excellent choice.

Re thicker oils, you can get the benefits of a thin oil with the protection of a thick oil, if the thin oil has a good HTHS.

Agree that noise is probably and indicator of damage - but ill pose the question on BITOG to see if they agree. FWIW, some additives reduce notice, and that's unrelated to viscosity.

BTW - i'm not saying you are wrong, I'm just saying I haven't heard anything that convinces me yet. I have cognitive bias that makes me see cognitive bias everywhere...

[scotty nm35]

I suspect the majority of the oil viscosity noise is coming from the VQ cam chain tensioners, the two smaller chains between the cams. These tensioners have restrictors in and out, and can bleed off too quick with a thinner oil, not pushing the chain with enough force to keep it tight. I find a 10w40 perfect to remedy these noisier engines. Any thicker simply makes the car feel lethargic.

Why don't you try a thinner oil and let us know how you go, I doubt it will stay in the engine for 2k let alone 10...

[Jetwreck]

Quite happy to see your results on a stock motor with stock boost and turbo on 30 degree plus days.

Have you checked the average temps between japan and Australia? Have you also taken into consideration the octane on fuel? What about the ramped up versions running more than 137awkws in 40 degree heat?

Please specify what brand of oil you are using as you did mention that different brands react differently.

Ps. Did the Australian complied r32's have oil coolers fitted for any particular reason? I've never gotten the full story on why they made that decision!

[nickcorr]

UK spec R33 and R34 had additional oil coolers for engine, transmission and diff, and I think higher final drives, for sustained high speed running. They also had full Connolly leather interiors.

I also know for a fact that none of the official press cars lived longer than 12 months before some journo wrote them off...

[MrStabby]

Ok, well you're both scaring me now, but ill still try the ?w-30 anyway. Probably Mobil 1 5W-30 ESP.

BTW - what oils do you both run?

Is anyone here running a ?w-30? If so, which one?

[Jetwreck]

I run neo 10w40 most of the time.

[Footo]

10-40 motul.. And royal purple in it at the moment as it was cheap.

because racecar

[gleeson]

10w40 gw for mine.

[Daleo]

GW Syn-X 6000 for me; which is actually 5W40.

[scotty nm35]

GW Syn-x 6000 here. More importantly is the drain interval, these engines have too many tiny restrictors on vital parts to skimp on oil changes. Buy a cheaper oil and drop it more often.

[PN-Mad]

Syn-x 6000 too.

I also run it in the track car, which takes a beating without issue.

[Daleo]

Syn-x 6000 too.

I also run it in the ass, which takes a beating without issue.

FYP.

[PN-Mad]

FYP.

Giggity!

[iamhe77]

Neo 10w30 (VQ35de) and change every 10,000.

Neo 10w40 or Motul 300v when I had the VQ25det, changed every 10,000. Anything else and I'd dump it after 5,000.

[Jetwreck]

Neo 10w30 (VQ35de) and change every 10,000.

Neo 10w40 or Motul 300v when I had the VQ25det, changed every 10,000. Anything else and I'd dump it after 5,000.

Was waiting for your input Cam.....and I totally agree.

[MrStabby]

FYI there's no love for using a 30, so apparently i'm a slow learner and a 40 is the way to go, as you've all been saying.

The Valvo SynPower 5W-40 seems fine, but Shell Helix Ultra 5W-40 might be a little better at the same price point. Mobil 1 0W-40 a little better still but more expensive, then Redline and 300v better still and even more expensive.

I'll get the SynPower tested at 10K to verify its ok for the full OCI.

[scotty nm35]

10k? If you like... Will you be changing filters every 5? It's pretty small...

For a stock M35 I believe GW synx 3000 is fine, dropped every 5k. At $22 a bottle you can't go wrong imo.

[iamhe77]

I ran just about everything during my VQ25det ownership.

Anything made by Valvoline, Shell, Mobil, Penrite, Castrol, GW, Motul (except the 300v line) etc I strongly urge you to drop every 5,000kms. VQ25det is quite hard on oil and lesser blends can certainly start breaking down in under 10,000kms.

Only oils that I used that were good after 10,000kms were Motul 300v Chrono (10w40), Neo Platinum 10w40 and the now unavailable GW Sougi S5000. Even Redline 10w40 started sounding harsh and feeling "loose" at around 8,000.

[MrStabby]

ok, i'll drop it a 5k and get it tested.

Last time i checked Redline had superior stats to 300v in the ones i cross checked, but all the manufacturers appear to be constantly improving their oils without changing the product name. They're both 100% group 5 oils, so should hold up really well. Interesting that it didnt appear to.

[MrStabby]

10k? If you like... Will you be changing filters every 5? It's pretty small...

For a stock M35 I believe GW synx 3000 is fine, dropped every 5k. At $22 a bottle you can't go wrong imo.

Suggesting a shorter OCI but a crappier oil - thats whacky logic! 180 degree about face