celeste

my friend recommended me mobil one SuperSyn, but
i am not sure which should i take:5w-30 or 10w-30?

could you provide comments?

SLC I30t

iTrader: (1)

I have 75k miles on my car and 5w30 burned off pretty quickly. I have good compression on a compression test and good vacuum, so its not faulty rings or valves. I switched to 10w30 Mobil 1 and it has done the trick... although I will be switching to Castrol Synthetic since Nissan recommends it over mobil 1 if you are choosing synthetic oils.

Dave Holmes

What do you mean it burns off pretty quickly? I'd check for a leak or something, 'cause my '97 SE with 68,000 doesn't "consume" any measurable amount of oil. I currently have about 2000 miles on Mobil 1 5w-30, and my dipstick shows the same amount as when I changed it. My owners manual says that Nissan recommends a 5w-30 regardless of temp, but a 10w-30 may be used. When did Nissan start recommending a certain brand of oil? I haven't heard anything about that.

Dave

Green 2kSE

That's a new one, got any proof?

SLC I30t

iTrader: (1)

Just nissan service. I've been told that from several different dealerships, but it took a conversation with the regional service director to really sway my opinion. I always had a high opinion of Mobil 1 because it is OEM oil for my dads cars, so I was like if its good for a Porsche then its good for an I30. When I was speaking to the regional service director the reason he stated was the sleeve inserts on the cylinder walls are the detergent additives in the syntec oil are somewhat reactive to each other, and the oil will bead up on it.

Dave holmes-I have no leakes the rear seal has no indication of a leak. I know that the owners manual states 5w30, but older engine do require a heavier weight oil. My seals and valves are in good shape and the car doesn't smoke when I start it or do stationary redline rev. Like I said I switched to a heavier oil and my car no longer drinks oil.

JAY25

iTrader: (38)

I did notice that dealers in different states use different oil brands, in California oil of choice Valvoline, in Miami oil of choice Castrol, In new Orleans oil of choice Pennzoil, her in Atl I had not paid much attention. So we cant guide ourselves but what the dealers use. This is a case by case thing. I am debating should I go up to 10W/30 and I am supercharged and oil cooler kit dont know if that would be a good idea.

Lime

I still use 5w. I'll let you know how the tests come out...kit should bearriving soon.

bill99gxe

iTrader: (1)

Whoever told you Castrol Syntec is more interested in selling their stock than telling you about the best mainstream synthetic out there. There are better oils out there.

http://forums.maxima.org/showthread....hreadid=100060

10W or 5W? Whatever you are comfortable with. If you live in the north, 10W is a probably bad idea.

You should probably be more concerned about your oil filter selection than your oil selection.

bill99gxe

iTrader: (1)

Our first Royal Purple test results.

iwannabmw

iTrader: (3)

I use 5W-30 year round in temps ranging from single digits to upper 90's with no problems whatsoever under some very harsh conditions. Bill's spreadsheet has great info on why some synthetics are better than others and how they hold up in the real world.

Oh yeah, my car is a 97 with 73K on it.

gsleve

If we are speaking solely synthetics the characteristics of the oil in terms of flowablility are neglegible a 5w will flow @ -60 below zero and a 10w will flow almost @ the same temp range give or take a few degrees, no one will be harming their motors if they are using a really good synthetic oil with these flowablility properties, although I question the Castrol hydrocracked stuff.

iwannabmw

iTrader: (3)

I've seen many people mention low pour points and low pumpability temperatures. Not one person has mentioned what the actual viscosity of these oils is at low temperatures. Just because it will flow, doesn't mean it's safe and okay to use it. There ARE differences between the two oils, regardless of the minimum temperature at which they show any movement.

First off, here are a few explanations of some different tests:

Pour Point - The test determines the lowest temperature at which an oil flows as the jar is tilted for a prescribed period.

Borderline Pumping Temperature - Borderline pumping temperature is a measure of the lowest temperature at which an engine oil can be continuously and adequately supplied to the components of an automotive engine.

Cold Crank Simulator Apparent Viscosity - Apparent viscosity has been estab*lished as a valid predictor of engine-cranking viscosities at specified low temperatures. Apparent viscosity depends on temperature and shear rate.

Looking at a 5W-30 and a 10W-30, we find that the 5W-30 has a pour point of -51 vs. -48 for the 10W-30. Small difference, who cares. The borderline pumping temperature of the 5W-30 and the 10W-30 is -40 degrees. Again, no difference. Here's my point. In the cold crank simulator at -13 F, the 5W-30 has an apparent viscosity of 2555. At a temperature of -4 F, the 10W-30 has an apparent viscosity of 3444. At a temperature 9 degrees warmer, the 10W-30 is 35% thicker.

Granted -4 is a little cold for some of the northern tier states, but many of them see temps. similar to those tested at, especially for those early morning starts. Looking at the numbers above, do you really think it's still a good idea to use a 10W-30 even though it will still flow at a colder temperature? For my engine, I'll take the 5W-30 any day.

celeste

great! Thanks a lot.

i will buy 10w for such a hot summer then change to 5w in the winter

as one mentioned, the selection of oil filter is more important than that of oil

i again have no idea about it, can somebody give some hints

Dave Holmes

SLC I30t, I hope you didn't take my post as a flame. I'm just trying to keep up with all the info out there about oils and such. My concern would be that a relatively low mileage engine (in my book, a Nissan under 100,000 is low mileage) would need a heavier oil to stop consumption. Makes me wonder where it is going, and why. Maybe it can be chalked up to every engine is different, break in procedure, driving style, etc... Both of my 4th gen Max's never "use(d)" any measurable oil. Even my wife's '88 Nissan PU w/168,000 miles doesn't consume any oil at all. My Max's only get a synthetic, currently Mobil 1 5w-30 in my '97, but used to be Castrol Syntec 10w-30. My main reason for switching to 5w-30 is that is what the owner's manual suggests, and I've had no problems whatsoever (might be psychological, but the engine seems to rev more freely?). I switched to Mobil 1 because of all the stuff Castrol was accused of, and research on the .org. Mobil 1 is also $17.88/5 qt jug at Wal-Mart! But don't get me wrong, I still think Castrol is a good oil. My wife's truck used Castrol GTX 10w-30 for about the first 70,000 miles I changed it, and now uses whatever synthetic 10w-30 I find relatively cheap. One question I think about is the drain intervals. Since none of my vehicles (including a rebuilt '78 Camaro w/210,000 miles) ever used any oil, can it be due in part to me being obsessive about changing oil every 3000 miles? (Let the flames begin by those doing extended drain intervals! But I'm going to live dangerously this time and go 7500 miles on my '97 SE w/Mobil 1 5w-30 before an analysis!). I think there are a lot more variables about oil, viscosity, and drain intervals than one first thinks about. Glad to hear you got the consumption issue fixed by going to a heavier oil. But that raises another question for me. Is it treating a symptom of an underlying problem (or potential problem), or is it simply that your engine is different than the ones I've had experience with? I hope this is a fair question, and I hope someone can shed some light on it for me because I am not an expert on the matter.

Dave

SLC I30t

iTrader: (1)

No no no, not at all. I had a compression test done to see if the rings were blown, and they are fine. I had a vacuum test done to make sure the valves are seating, and they are. We checked for leaks... none I took the fill plug off to see if there was excess oil in the tranny from a faulty rear seal and none poored out so there was no excess there. The plugs were nice and brown. I think that it was just too thin of an oil to be racing(high RPMS) on. I do take my car to 5k rpms once or twice a day. Then when I was told about the Mobil 1 thing-( I know people are having issues with it) I switched, and so far 1k miles down and I seem to have not lost any oil, but I really wont know till I change the oil in a few months. there is simply no other explaination for the loss of oil that I was having.

gsleve

First off lets look at the requirements nissan set in terms of grade of oil one would use. These requirements were given to satisfy the api which is solely premised on petroleum oil yes a 5-30 in terms of pertoleum compared to a 10-30 of like kind the 5w would be better, however lets compare this to a synthetic a 10w in the synthetic realm will out class a 5w petrol in all categories no issues here a 5w in the synthetic realm will out class a petrol also, point being even if one were to use a 10-30 in synthetic they are in terms of the manufacturer and api the owner is exceeding the the requirements spelled out by a looong margin if you were to compare you ccs in the pertol world I concur with you concerns, however again we are speaking of synthetics were the flow capablilities far exceed the requirements of the manufacturer.

I'm sure if you were to compare two vehicles of like kind and quality and mileage driven in the same conditions one using synthetic 10w-30 and on one using 5w-30 the differences in wear would be negligeble if not non appreciable.

iwannabmw

iTrader: (3)

I understand your point about comparing a synthetic to a petroleum oil. The numbers I posted before compared a synthetic 5W-30 to a synthetic 10W-30, specifically Amsoil, because it's usually easier for me to get numbers from them. Even being a high quality synthetic, the numbers are much different, indicating the 10W-30 is much thicker. Adding petroleum oils into the discussion isn't really worth it, they are so far behind it isn't even funny.

As for Nissan's requirements, how low do they set the bar and how high do we want to raise it??

I also understand your point about the CCS numbers being that much better for a synthetic 10W-30 vs. a petro 5W-30, and I'm not trying to say using a synthetic 10W-30 is dangerous and could hurt the motor in any way. I'm only trying to point out that there is still a big difference between a synthetic 5W-30 and a synthetic 10W-30, regardless of what ridiculously low number they will pour at.