Quick Oil Question

[UofTCadet]

I'm on my second oil change and forgot the weight of the oil I use. Smart huh?

The car's always used Royal Purple and I'm pretty sure it's either 10w40 or 5w40. It might be 30 though. Does anyone know what I should be using? Here's the specs.

1994 Z32 Twin Turbo
88,000 miles

Thanks for the help!

[Chattzx]

10W-30 or 5W-30 its your choice. I personally use 10W-30 for the hot summers and 5W-30 for cold winters.

[UofTCadet]

Awesome. 10w30 it is then down here in Texas. Thanks for your help!

[Chattzx]

No problem man.

[vulcanrush]

if you're in texas, wouldn't hurt to run a 40-weight.

[Chattzx]

Yeah I mean your not gonna notice any difference so its really up to you, 40 weight is a bit much unless you have it in high rpm's quite often.

[vulcanrush]

he has a tt, which generates more heat, and in texas also --- a 40-weight oil isn't too much. rpm's don't really matter, the bulk of his powerband is from 3.5k to 5.5k rpm's. it's just a tt takes a lot of abuse, and considering it doesn't get that cold where he is, he could run a 10w-40, even. redline is pretty good, but kinda pricey.

[Chattzx]

stick with mobil 1

[vulcanrush]

you can check out bobistheoilguy.com/ forums for more info, it's pretty neat.

as for mobil 1, the european formula (mobil 1 0w-40, etc.) is the best.

the rest of the line is pretty average, there's better out there.

[UofTCadet]

Thanks for the additional info. I used Mobile 1 in my 350Z, but have been on Royal Purple in the Z32. There's a fantastic Z shop here in Houston, "Awesome Z", and they highly recommend Royal Purple. They do great, honest service at a reasonable price and I trust them 100%. There's a master Nissan technician who runs the shop and he feels pretty strongly about RP, especially for the TT.

I am open to other opinions though. Any reasons why y'all feel the way you do about Mobile 1 vs. RP?

[vulcanrush]

you can get a uoa (used oil analysis) test to see how the oil is doing in your car, i've gotten a few, they're pretty cool.

i personally don't really have an opinion on royal purple...i don't think it's the best because it has a tendency to shear (get thinner)...for the price, i'd rather get redline.

i run mobil 0w-40 (factory-fill for the nissan gt-r, evo, amg, porsche's, etc.).

german castrol 0w-30 is also good.

[Chattzx]

But dont use 0W-40 if you have leaky engine seals, bc its so thin it will leak out easily.

[vulcanrush]

that's not true, it just flows better in lower temperatures. it's a myth with synthetic oils that it'll leak, etc.

it's actually thicker after the car warms up.

[robomatic12]

But dont use 0W-40 if you have leaky engine seals, bc its so thin it will leak out easily.

False. Do some research on bobistheoilguy.com to review all the different oil myths. 0w40 is thicker than a 0w30 for example once warmed up. The 0w40 will flow better at startup and less strain on engine parts than a 5w40 or 10w40 for example.

IMHO I would use a 5w30 or 0w30. Thicker is not necessarily better if you do not need it to be thicker.

[Chattzx]

I know 0W-40 is thicker than 0W-30. I was comparing it to the likes of a 10W-30 as it is much thinner "when cold."

[robomatic12]

Ok I get what you are saying but regardless it shouldn't make the oil leak out. If it started leaking because of the oil change it was always leaking, just masked by sludge buildup.

[NissanFairladyZ32]

10-30 Mobil 1 Syth

[es.biggs]

it's a myth with synthetic oils that it'll leak, etc.

How do you figure? Synthetic oil IS more prone to leak because of the molecular makeup. Synthetic oil is uniform, dino is not.

[vulcanrush]

Ethan,

this is what valvoline says on their website:

http://www.valvoline.com/car-care/autom ... 20080401v3

"Truth
Especially for those specifically formulated for higher-mileage engines, today’s synthetics work just fine in older cars. Synthetic is no more prone to leaking than conventional oil. This fallacy might have been created by some synthetics from the early ‘80s."


http://www.texlube.com/oilmyths.htm

Myth #5 - Synthetic oil causes engine leaks. Synthetic motor oils eat gasket material and cause engines to leak. Synthetic motor oils affect engine seals and result in excessive oil leakage. Synthetic oil can’t be used on high-mileage engines. Synthetic and synthetic blend motor oils cannot be used in older or high-mileage vehicles.
Fact: Synthetic oils do not cause engine oil leaks. Deteriorated and hardened seals and gasket material cause engine oil leaks. If the seals are already leaking with conventional motor oil, they will leak with synthetic oil. If the seals are in good condition, synthetic oils may be used in high-mileage engines.

it's not the oil, it's the seal. it flows better, in cold conditions, etc., but it's not more prone to leak.

[es.biggs]

That's dumb man. Of course its the seal not the oil. Given that there is a leak, synthetic oil will leak faster than conventional. That's all I'm trying to say.

You can quote all the Valvoline you want but Valvoline is going to sugar coat synthetic oil because they want to sell more of it. Don't trust it...that company is completely money focused to a degree where it is disgusting. I worked there for over a year.


Get two quarts of oil. 5/30 dino and 5/30 synthetic. Get two Styrofoam cups. Poke 4 pinholes in the bottom of each cup. fill the cups halfway simultaneously. Which one will empty first? Synthetic, I guarantee it.

[vulcanrush]

Ethan,

a styrofoam cup isn't exactly scientific. it has no similarities to an engine.

with the lawsuit culture that we live in, i don't think valvoline is going to give bad information, too liable.

virtually every source online says synthetic oil doesn't leak more than conventional. please find one source that says it does.

yours is an opinion. i'm not stating my opinions, just providing what informed experts on the subject think.

i'm going to think valvoline knows more on the subject than you do. just like they know more than i do.

http://www.waynesgarage.com/docs/synthetic_oils.htm

"Myth: Synthetics cause cars to use more oil.
Untrue. A leaking engine will leak the same amount of either. Unless an engine is a real oil burner, it will burn less synthetic than regular. "

they're not prone to more leaking.

http://www.ehow.com/about_5510369_synth ... myths.html

"Synthetic Motor Oil Causes Engines To Use More Oil
In the defense of synthetic motor oil, the opposite is true. The use of synthetic motor oil has proven to actually reduce the consumption of oil. Synthetic oil has more efficient sealing characteristics than conventional oil, therefore resists leaking through piston rings and cylinder walls."

too much bad information gets passed around.

[es.biggs]

Ethan,

a styrofoam cup isn't exactly scientific. it has no similarities to an engine.

with the lawsuit culture that we live in, i don't think valvoline is going to give bad information, too liable.

virtually every source online says synthetic oil doesn't leak more than conventional. please find one source that says it does.

yours is an opinion. i'm not stating my opinions, just providing what informed experts on the subject think.

i'm going to think valvoline knows more on the subject than you do. just like they know more than i do.

http://www.waynesgarage.com/docs/synthetic_oils.htm

"Myth: Synthetics cause cars to use more oil.
Untrue. A leaking engine will leak the same amount of either. Unless an engine is a real oil burner, it will burn less synthetic than regular. "

they're not prone to more leaking.

http://www.ehow.com/about_5510369_synth ... myths.html

"Synthetic Motor Oil Causes Engines To Use More Oil
In the defense of synthetic motor oil, the opposite is true. The use of synthetic motor oil has proven to actually reduce the consumption of oil. Synthetic oil has more efficient sealing characteristics than conventional oil, therefore resists leaking through piston rings and cylinder walls."

too much bad information gets passed around.

I found a site that explains exactly what I'm trying to say:

Myth #2 debunked

Synthetic oil causing oil leaks is another commonly spread myth. The truth of the matter is that if all your engine seals and gaskets are in good condition, synthetic oil will NOT leak in your engine. The myth started because on occasion, an engine will leak with synthetic oil, but not dino oil. The reason for this is that the smaller molecules of the synthetic are able to get past very small crevices, where the larger molecules of dino oil cannot. But this does not mean that the synthetic oil has caused the leak, it simply has "discovered" an infant leak, and regardless of what oil you are running, this infant leak will eventually grow to a size that will allow dino oil to occupy and pass also. Synthetic oil has not been shown to deteriorate engine seals or gaskets. It is not some evil solvent that will break down sealant, or anything like that. Like was said earlier, it is just a man-made base stock, that is uniform and smaller in molecule size than dino oil. Nothing more, nothing less.

from http://www.aircooled.net/gnrlsite/resou ... nthoil.htm

As far as feeding into the Valvoline pitch on synthetic oil - I've been on the service side of that company and I know how the company works from a completely different perspective than most people. I'm guessing you've seen a few advertisements, read the website, and maybe even bought some Valvoline oil at your local Carquest. That's great, and I even use a few valvoline products as well - they are great products. They want to make money though, as does every other business in the world. No way is Valvoline going to say anything negative about their most profitable oil. It's just business. Believe what you want man, it's no big deal to me. Just want to let you in on another view. I mean, they tried to have us seriously tell customers that "nitrogen filled tires make your car ride smoother and your tires last 50% longer" --- it's all just about the money! Which is a big reason I left. Plus, the pay is crummy as a lube tech

Ethan,

a styrofoam cup isn't exactly scientific.......

........"Myth: Synthetics cause cars to use more oil.
Untrue. A leaking engine will leak the same amount of either. Unless an engine is a real oil burner, it will burn less synthetic than regular. "

"a real oil burner" isn't exactly scientific either. My point was to prove that synthetic oil flows more freely than dino oil because of the uniformity of the molecules that make it up. Synthetic oil is "perfect" in that the molecules are all the same exact size. Dino oil has many different sized, larger molecules. Think of a cut and how erythrocytes and thrombocytes (red blood cells and platelets) affect the rate at which blood flows out of the cut:

Synthetic oil could be compared to blood with only RBCs. The blood is uniform because all of the cells are the same. But the problem is, the blood will continue to flow from the cut until the cut is fixed via stitches.

Dino oil is somewhat comparable to blood with both RBCs and platelets. The blood has different sized cells that can stack up on eachother and prevent the blood from flowing through the cut.

See what I'm tryin to say? I mean...I don't know lol I'm getting distracted and this is getting boring to be honest haha. Short attention span FTL. Not saying oil is anything like blood...just trying to illustrate a little bit for ya.

EDIT - I am not trying to be rude man, sorry if I came off that way!

[Chattzx]

How many more oil topics will these forums get