aga

ok it's another oil thread but hear me out please.

i used to put amsoil 15-50 dominator on all my turbo cars. never had a problem.

a friend said that thick oils damage the VTC over time, and the local distributor stopped bringing 15-50 dominator so i asked him to recommend me another oil

he recommended 10-30 lucas racing oil. a friend with an s14 was using it as well.

only thing that bothered me was the RACING USE ONLY label. so i'm leaving for a trip tomorrow but i researched into it cause i had heard about MOTUL 300V racing oil that it was good only for 20 cycles of heat...

looking into it i found out that racing oils have too much zinc and phosporus, that do great things for lubrication but over time they attack the iron, damaging camshafts cylinder walls etc. so they are recommended only for engines with a short life. does anybody know more?

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l adam l

I Used Vr1 20-50 in my old sr20...changed every 2500 - 3k miles. Had my sr for about 60k miles before i sold it...no driftin besides a few times in an empty parking lot had a few 1/8th mile runs too...I know the reason it's 'racing only' is because it burns off the extra additives and it'll clog cats. I'm mlt1 certified in lubricants...

aga

that's what i heard about the amsoil dominator but i don't care cause i dont have a cat in the car...if that's all there is, i'm relieved.

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l adam l

Yeah just try to stick to whatever oil you change to because they all have their own special detergent and additives that could react with other stuff. Just be religious about changing it the first 2 or 3 times and you'll be fine.

aga

so you think i should keep it for 3000miles? (around 5000km)

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l adam l

Yeah that'd be fine. I'd try to do it at about 2500km or so if you're hard on it - but if you just do SOME spirited driving here and there 5000kms is definitely fine. A lot of heat plus different detergents is where you get into problems. Just stick to that oil when you change.

aga

the car is a street car, used daily, so 99% it's cool driving. even when i'm hard on it its no more than 30 sec...

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rpierce

I've heard great things about Shell Rotella T6 for street driving or track. People use it in pretty much any turbocharged cars (lots of turbocharged subarus use it) and a lot of people use it in their track bikes since its JASO-MA certified for motorcycles.

I've used it for 2 years in 2 of my motorcycles and my car and I've never had a problem with it. Turbodiesel oils still have more of the old timey additives that they dont allow in car oils nowadays because they damage cats and such.

KoukiMonsta

T6 and purolater pure 1

done and done

l adam l

T6 is good stuff I just don't like the 0w stuff.

Tom N

Racing oils like Valvoline VR1 are high in ZDDP. The zinc in it attaches it self to interior metals and acts as a film that helps keep metal on metal wear. This is very important in cam lobe wear and journal bearing turbos.
The Phosphorus in ZDDP clogs cats and is why oil manufactures have reduced the amount of ZDDP found in conventional everyday oils.

I don't see how a 15w50 oil is damaging the VTC gear.

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AS240

+1 for T6. I've been running it in my cars for 4 years and couldn't be happier, especially since it's $22 for a gallon at walmart. I also run amsoil oil filters.

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Kaifd3s

15w-50 Mobil 1 here. No problems, and honestly I never tried anything else. I used to run 20w-50 VR1 in my FD, but I still never tried anything else.

I change the oil religiously on my car tho. I think that has to be the biggest problem. Owners not changing the oil soon enough.

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aga

i ve heard that high zinc oils clog cats, and O2 sensors... in my previous car I was using amsoil dominator 15-50, but had no problems... the wideband sensor eventually died, but after 4-5 years...which is kinda normal, i guess. it's a cheap part to replace anyway.

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anti tyler

Everyone has their own rituals and superstitions.

I've used royal purple in my kat since it was born in 2008. never had an issue.

you have to look at it like this, if you're a zinc lover and I have an oil special on sale at advance, I'm going to tell you to use what you're comfortable with.

The market is so vast now that there are zinc oil additives for those people who just can't live without it.

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Croustibat

"oh look, another oil thread"

racing oil means it usually does not follow road regulations, and it wears quickly.

anyway, if you understand the concepts of oiling and the way your oil pump works and regulates the flow, you want the thinnest oil your engine can cope with. you can check this with an oil pressure gauge, and by reading the pressure thresholds in the FSM. Usually, these engines need something near 10w40, but you might want 10w50 if oil temperature reaches 110 or 120°C . If you can put 5w50 without hearing your lifters make strange noise, by all means use it. You really want 100% synthetic in your engine, the longer oil life offsets the price.

15w50 is plain stupid now that oils are stable. It made sense 20 years ago. It does not now. Same goes for 20w50.

/endthread

aga

relax crousti..."endthread"

oil is a topic that will always be coming up because nobody can test it. nobody can say with absolute certainty "this oil is bad this oil is good" , everyone can challenge their opinion.

for example. i used eneos 10-40 and motul 300v on the SR, both oils were smelly, and there was a lot of sound from the head. with amsoil dominator 15-50 and lucas racing 10-30, the car was quiet, had no oil consumption, and with the 10-30 i felt a performance increase.

plus rumor has it that thick oils wear out the VTC faster.

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Croustibat

FUCK. THAT. DAMN.CRAPPY. NOTEBOOK. WITH. ITS FUCKING. CRAPPY. TOUCHPAD.

It erased my answer TWICE. Someone PLEASE KILL THE BASTARD THAT DECIDED TO POT A FUCKING TOUCHPAD THERE.


Short version: use the thinnest oil your engine can use. That means 5w40 on street use, 10w40 if your hydraulic lifters can't cope with it or your oil pump is wearing out, 5w50 or 10w50 for track use. If you need thicker oil to get in the threshold nissan defined in the FSM, your oil pump is worn or you have a serious oiling problem.

If you want to know more about it, search for my nickname about oiling, or send a PM in a week and i'll explain better, when i won't have to suffer from that crappy notebook.

l adam l

Before you say it's 'plain stupid' you do know that the w for the 20w actually means winter and not weight? And these multi grade engine oils use something called a viscosity index improver. These can shear through mechanical wear within a few hours of use making a 20w-50 have a grade of 15w-40. If you want to run a 5w-40 or whatever that's fine, but know once it 'shears' it could be a 0w-x.

Also once oils(0w-40, 5w-50, 15w-50, etc) reach operating temperature it now has a 40-50(second number) viscosity and your engine has to work just as hard to pump that 5w-50 as it would a 20w-50. The only 'hard wear' on parts is initial start up.

I'd rather have the protection after the shear factor than not have it and need it.

l adam l

Regardless of all this jabber...honestly the best thing you can do is have CLEAN oil. Run an oil filter that filters 99% or more. Even with the 0w stuff the zddp additives keep from metal on metal wear. It's the little dirt particles that kill your bearings, etc.

bataangpinoy

I am running VR1 Race 10w30 Synthetic in my s15 SR.
I kept a sharp eye on my oiltemp and pressure gauge during a recent drift event.

It will get thin if you get it over 200* F. Pressure gauge indicated that pressure would flicker to 9psi at 700RPM idle when the oil is at 210* F.

Once the temps cool to under 199*F, oil pressure again stabilizes and will not go lower than 10.5-11psi at 700rpm.

Changed after the event, oil is clean, no metal found on magnetic plug.


In my s13 sr20 I ran VR1 20w50 (lack of vtc allows for thicker weight).

Here is a good read, followed by a very comprehensive series of lab tests. finally, data to back the claims.


http://speedtalk.com/forum/viewtopic.php?t=30483

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Croustibat

I know all that, and it is at the hearth of the whole problem. That shear factor was very true 35 years ago, and was the reason people used 20W50 oil while racing; because at the end of the race, it would have transformed into a 0w30 at best.

But that was 35 years ago. Oil manufacturers have gone a long way to improve their products, and it is not true anymore. using 15w or 20w oil makes no sense now, because oils wont shear that much.

The funny think about thicker oil is that by using it, you are lowering oil flow quite a lot, create heat management issue ... and decreasing oil life. Exactly the opposite of what was wanted at first.

Actually there is a second reason people started using very thick oil, and it still is the same reason people use it now: stupidity.

Years ago, tuners found that increasing oil pump flow by adding washers to the oil regulation system was very good. the downside of this was increased pressure, and eventually cavitation problems.

But somme pretty thick people saw the increased oil pressure on the gauge and went "hey! moar pressure = moar reliability ! Lets put thicker oil so we get more pressure !".

Pretty ironic, but hey ...

l adam l

Dude a 5w-50 and a 20w-50 ARE THE SAME VISCOSITY SAE 50 AT OPERATING TEMPERATURE. The oil is ONLY thicker when it's COLD. Make sense?

l adam l

Also people use thicker oils because it holds viscosity at higher temperatures...I.e. drift car, drag car...race car. Put that 5w-20 in your car and wonder why your pressure drops to shit once your engine reaches that 200*F mark and fries your shit. I'll go ahead and keep using my 'stupid' oil that keeps it's viscosity at ~300*F.

Learn some shit before posting
/endthread.

Kaifd3s

Best comment yet.

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Kingtal0n

Hey I agree. Use thin stuff and watch your oil pressure.

Heavy weight oils are for people that know their bearing clearances. Do you know yours? Is it .0025"? Then don't use 50w oil in 60*F temperatures.

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Kingtal0n

You want oil to pass 212*F to remove water molecules.
Engines that routinely fail to hit those oil temps build up water over time in the oil, and experience premature wear and tear. Like weekend cars that only see the grocery store. this is well know since the 60's when the idea of lower temperature thermostats became a "high performance notion". There are many books about the subject, some by "david vizard" and " smokey Yunick" iirc that document peak power at temperatures right around 212*F coolant.

Kingtal0n

this is what they will tell you. And it may be true.

however, to get that obvious advantage (you make it looks like a clear advantage to run the 5-50 because of it's wide range) As a side question, Why do you think they still make the 20-50? Since 5-50 is clearly advantageous.

The truth is, unspoken, to increase the range between numbers, there are changes to the organic chemistry, hydrocarbon chain designs may be different, and there are probably more additives. In other words, you may be getting less actual oil, and more additives, when you start to use wide spread numbers.

Many of the high dollar high displacement applications, such as 1200horsepower V8 580cubic inch boat motors, will only run a straight weight oil.
And have great consistent results with it for 20+ years.

l adam l

It's not weights it's grades...sae grade. The w stands for winter, not weight. Higher sae grades are for people needing an oil that holds its viscosity at a higher temperature.

I do agree if you're never drifting, drag racing/ hard oon your car to use the thinnest oil possible. I run 5w-30 in my ka24 240 because i never am hard on it. But when your Temps are up you need that thicker viscosity so it still has its lubricating properties...to protect your engine from metal on metal contact.

l adam l

You know for the most part straight sae 50 has a lower viscosity than a 5w-50 or 20w-50? The viscosity index improver sometimes puts it up more than 50.

also about the 'range' you mean between the time you start your engine until the engine warms up...I guess if you need that 'range' idk what it would be for but hey go for the sae 5 then. Once it's up to temp it's a sae 50

while it may be true that you're getting less oil...you're still getting more zddp. And the number is very small... we're talking PPM (PARTS PER MILLION) or roughly 2-3% of your oil.

also if anyone cares to pm me I'm getting curious about the before and after oil Iin drift events. I have the Nissan pdm lab at my disposal. Send me a sample of both new oil and after drift event and we can see how much they'd shear.