The last 5W-30 vs 10W-30 thread of all time

[itguy08]

Originally Posted By: Merkava_4
I keep thinking the engineers must've had a reason for mandating 10W-30 at the time; I wonder what that reason was.

Except they didn't mandate it....

https://my.buick.com/content/dam/gmowner...abre_owners.pdf


Page 6-13
Quote:
As shown in the chart, SAE 10W-30 is best for your vehicle. However, you can use SAE 5W-30 if it’s going to be colder than 60F (16C) before your next oil change. When it’s very cold, you should use SAE 5W-30. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity oils, such as SAE 20W-50.


The Handy Dandy chart only says 10w-30 is preferred. Not required.

 

[John_Conrad]

i have been using the 5w-30 in my 1997 oldsmobile 88 for a many many fills now. i am approaching 400k miles real quick on this engine. that having been said i am in the midwest and "i" feel better with the 5w-30 with our cold winters.

amazon has the 10w-30, but it's a bit pricey:
https://www.amazon.com/Castrol-03072-Magnatec-10W-30-Motor/dp/B00TS9ZZ0Y?ie=UTF8&*Version*=1&*entries*=0



if you like you can get on the walmart web site and sign up to get an "in stock alert" if and when they get some of the 10w-30.

good luck

 

[SwampSurvivor]

Well if it's that old I'd run 20w-50 in it. No reason to stick with the super thin fuel economy oil if it's out of warranty. That should give adequate protection.

 

[crazyoildude]

If the engine does not leak 5w30 should be fine however i would use the 10w30 in the summer months. Those engines run for a long time.

 

[HTSS_TR]

Originally Posted By: Merkava_4
Originally Posted By: Garak
Are you worried about the warranty recommendations on a 17 year old vehicle?

I keep thinking the engineers must've had a reason for mandating 10W-30 at the time; I wonder what that reason was.

Shear stable.

 

[Garak]

Originally Posted By: Merkava_4
I keep thinking the engineers must've had a reason for mandating 10W-30 at the time; I wonder what that reason was.

Fair enough. However, does it even pass the smell test that only one grade of oil is acceptable under all usage patterns and ambient temperatures? And do note that there are some pretty wide ranges of viscosities available, even in one SAE grade. I've already pointed out to you a few 5w-30 examples (and 0w-30 examples) that are significantly thicker than an ILSAC 10w-30. Basically, going to a 5w-30 or 0w-30 in your climate could actually get you a thicker lubricant at operating temperatures than what you're using now.

I have no problem going out of spec, particularly in a reasoned fashion, when the vehicle is old enough that the oil specification is outdated, particularly if oils have come a significant way since the date of the vehicle, or if the oil recommendations are plain silly when looked at today.

Look at this oil chart from the oil Audi I had:

That's a perfect mix of outdated and silly in today's context. Where in the heck am I going to find a 10w, a 20w-20, a 20w-40, or a non-ILSAC 5w-20? Who uses monogrades, either? And do you honestly think I want to have seasonal oil changes? While the chart is still valid and works as intended, with what's available these days, trying to follow it would be silly.

I went with 5w-40 once winter hit in that vehicle for a reason. I did a fair bit of 15w-40 in the summer, but seasonal switching gets old in a hurry. A 5w-XX is good for the winter. The grade also has sufficient HTHS for summer use. Despite that fact that 5w-40 doesn't even appear on that chart, it made a fine, year round choice. Oh, and I did 0w-40, as well, which wasn't on there, either.

One has to know what one is dealing with with an oil grade. They want a 5w-30 only below freezing. Of course, in those days, they were talking about energy conserving 5w-30s. I'd have no hesitation using something like Castrol 5w-30 A3/B4 or Mobil Delvac LE 5w-30 year round in it, since it will also have the HTHS of the higher SAE grades along with the winter numbers I would need. The same would apply with respect to GC 0w-30 or Mobil Delvac Elite 222 0w-30, despite that grade not appearing on the chart, either.

Given that you tend to use synthetics and very short OCIs, the last thing you need to worry about is shear stability. As I've said before, if you think an ILSAC 5w-30 is too thin to run, then an ILSAC 10w-30 is not the solution to this perceived problem.

 

[Merkava_4]

Originally Posted By: itguy08
Except they didn't mandate it....

https://my.buick.com/content/dam/gmowner...abre_owners.pdf


Holy smokes! You mean they got my owner's manual on the internet for the whole world to see ?

 

[Ramblejam]

Is it the forum version of jumping the shark when someone who has been here for nine years, and has over 14,000 posts starts a thread like this?

 

[Prune_Juice]

Originally Posted By: AZjeff
Don't do it. The slightly easier to pump at start-up oil will ruin your engine. Unless you only turn left at stoplights and park in the far right spot facing out. Then you're fine.

 

[Greggy_D]

Originally Posted By: Ramblejam
Is it the forum version of jumping the shark when someone who has been here for nine years, and has over 14,000 posts starts a thread like this?



He is a [censored] stirrer. Nothing more, nothing less.

 

[fdcg27]

If I lived in a moderate climate as you do, I'd use a real oil, not this watery ILSAC stuff.
Walmart has M1 15W-50 everyday for around twenty five bucks or so a jug and if that's too thick for you, they offer M1 0W-40 for the same coin.
You want an oil that complies with the OM recommendations?
M1 HM 10W-30 will run you about the same.
Seriously, though, I find it really hard to imagine that a good 5W-30 wouldn't work just fine in this engine.
What the OM says may have dated from a time when there were real concerns about 5W-30 shearing an entire grade in short order.
Those times have passed.
The oil recommendations in the OM are probably a carryover from those of a prior period, as is often the case.

 

[Merkava_4]

fdcg27 - Is M1 HM 10W-30 or M1 0W-40 gonna be that much thicker than an ILSAC 10W-30 ?

Would the engine run smoother and quieter on either of those two oils ?

 

[KCJeep]

Originally Posted By: Merkava_4
fdcg27 - Is M1 HM 10W-30 or M1 0W-40 gonna be that much thicker than an ILSAC 10W-30 ?

Would the engine run smoother an quieter on either of those two oils ?


Oh yeah big time. The HTHS on HM 10w30 is 3.5 and the 0w40 is a bit more than that. A typical 10w30 like PYB is usually about 3.1.

 

[Nitronoise]

IMHO , when I had ZZ Performance do some work for me when they returned the car to me it was filled with Mobil 1 5W30 full synthetic

I think they know a little bit about 3800 motors as they specialize in building hotrodded v-6's

I think you can dare to run 5W30 in your 2000 Buick

 

[HTSS_TR]

For California vehicles with 5W30 as recommended oil 10W30 can be used all year without problem, but if 10W30 is the only recommend grade then it should be the only one to be used, may be xW40 but not 5W30.

Honda recommends conventional 10W30 for S2000 for temp above 0F and 5W40 for below 0F. Pennzoil Platinum 10W30 was in engine for around 5k miles(OCI should be 7.5k miles) and it sheared down to 20 grade. UOA was done couple months ago.

 

[BrocLuno]

10W-30 is readily available at almost all the parts houses (NAPA, O'Rielly's, etc.). On a car that old I would have moved on to HDEO a while back. But you can get the preferred oil in lots of places...

How many miles are on this thing?

 

[MuzzleFlash40]

You'd better keep 10w30 in there. After all the pro 10w30 remarks over the years, your head will explode worrying about it if you switched! haha

 

[SavagePatch]

Originally Posted By: BrocLuno
On a car that old I would have moved on to HDEO a while back.


Are you thinkin' what I'm thinkin'? Delo 400 Severe Duty 15w30 (O'Reilly's) or Maxlife Heavy Duty 15w40 (WalMart)?

+1 What's the mileage?

 

[Garak]

Merk, I bet if you asked GM themselves, they'd tell you that a dexos1 5w-30 is perfectly acceptable.

 

[virginoil]

Originally Posted By: virginoil
This what I found on a USA Buick Forum for 2000 to 2005 LeSabre models.

The factory recommended oil is 10w-30 and 5w-30 for colder periods.

Are we on a fishing expedition ??


Not available. Gone fishing with Merc.