Oil choice for LSI...

[mmarx]

Newbie/Lurker here...I have a '02 Avalance w/5.3 LSI with 35k miles on it. I have been using various M1 products, 5w-30, 10w-30, and 0w-40 and with these oils the engine is noisy both cold and warm. I switched to M1 15W-50 and the engine is now clatter free and MUCH smoother.
My question is; should I stick with the 15w-50, or try Amsoils 10w-40 HP Oil, or even the 15w-40??? Any suggestions would be appreciated...
Truck is in Fl, about 300mi/week and see's some hauling.
Thanks...

 

[wwillson]

mmarx,

I use Delvac 1300 15w-40 in my '02 suburban. I'll tell you that the LS1 loves this oil. My engine is very quiet and uses very little oil. Take a look at the UOA I posted UOA

 

[mmarx]

Last_Z, No change in mileage...I check it everyweek.

heyjay,I do frequent a couple of different truck boards and an Avalanche site...I have had three different 5.3's and used heavier oil in all three. I went with the M1 0w-40 due to the ACEA A3 Rating, as I am looking for longer drain intervals. I just couldn't stand to hear the noise at start-up!!
FWIW, we (contracting business)have a 2500LD w/6.0 that has had Castrol 20w-50 used in it since day 1...over 80k miles and the truck doesn't use any oil and is silent. This truck travels all over the U.S. and it gets 20w-50 regardles of where or what time of year it is.

Any comments on using the Amsoil oils??

 

[heyjay]

Well, I've said it before and I'll say it again:

CAFE is a crock of s***.

Just like when I bought new my 1990 Toyota 4Runner I ran Mobil Delvac 1 5W-40, as that what my commercial fleet was using. When I moved to Utah I switched to Mobil 1 15W-50.

No difference in fuel economy. None. Except the motor seemed a bit quieter.

As an experiment, I did try running Mobil 1 5W-30 in June in Salt Lake City. Boy was that a mistake: valvetrain noise that drove me bonkers:

tickticktickticktickticktickticktick

And there was NO difference in fuel economy between running the Mobil 1 5W-30 and the Mobil 1 15W-50.

You should post your findings at the GM Trucks forum. A lot of folks there complain about their startup noise and their oil consumption.

When the 1992-1996 Ford Crown Vics had bad valve seals, Ford tried to convince the owners that 1 quart every 900 miles was "normal."

Now GM is trying to convince Vortec truck owners, especially the Vortec 8.1 crowd, that 1 quart every 100 gallons of gas is "normal."

Maybe it is, if you run a cheap dino 5W-30.

At 1 quart every 100 gallons of gas, you won't get 25,000 miles out of the O2 sensors and catalytic convertors.

Jerry

 

[heyjay]

As far as selecting Mobil 1 15W-50 or the Amsoil oils you mentioned, both are a GOOD choice. I'm sure you'll be happy with either.

It does appear that Mobil 1 15W-50 is EM's best oil. Delvac 1 5W-40 is also an excellent oil, especially if you extend the drains to make it cost effective.

Hope this helps.

Jerry

 

[Losiho]

quote:

---

Originally posted by heyjay:

High performance Holdens in Australlia appear to use 10W-40, 15W-40, 15W-50, and 20W-50. In the same exact LS1 motor.

---

As mentioned in other posts recently, the factory fill and recommended oil for HSV Holdens is M1 10w30, which as others have said is a little thin imo. The LS1s down here seem to suffer the same piston slap and oil burning problems they have in the USA.

 

[TooSlick]

The Mobil 1, 15w-50 is highly friction modified, so I'm not surprised that fuel efficiency was the same as with the 5w-40 diesel oil. Organic FM's are typically good for a gain of about 2% in fuel efficiency ....

I've seen similar fuel efficiency with the Amsoil 20w-50 racing oil and their 15w-40 diesel oil, even though the 20w-50 is 25% thicker in terms of HT/HS viscosity. If the Amsoil 10w-30 is too thin for a particular application, I'd skip the 10w-40/15w-40 and use the 20w-50 racing oil instead.

The 15w-50 and 20w-50, synthetic racing oils generate the lowest wear rates I've seen in engines that allow the use of these grades ....

[ February 20, 2004, 08:26 PM: Message edited by: TooSlick ]

 

[Last_Z]

It's official......I'm running all 15W-50 as soon as I finish my ARX treatment. It's fixing to get hot here in TX anyway.....it was 81*F today (eat your heart out Patman....you too heyjay

) and we might have just a few more days of very mild cold and that should be it!

heyjay,
Fortunately, my LS1 never burned any oil, no matter what weight. It did slap a lot though, but I just had GM put new pistons and rings in it and the slap seems to have at least, quieted down a LOT. I'm hoping the 15W-50 will quiet it down even more.
How low a temperature can the 15W-50 be run?
Thanks

Rick

 

[Last_Z]

TS,
What adds are the FM? Calcium and Zinc?

I forgot to mention.....the coldest I've seen here in San Antonio is something like 17*F and that might have been with the wind chill. Such temperatures do not last very long, just 2 or 3 days, then it's back to 30 and higher.

Pat, eat your heart out once again!!

 

[Patman]

Hey it's not that cold out right now, we're going up to 40F overnight tonight (it's colder now, but a warm front with rain is moving through)

I applaud you for trying out 15w50 in your LS1 and doing a UOA (since I can't convince any other 15w50 users with LS1s to do a UOA), although I have a strong feeling you'll see higher wear. The LS1 doesn't like a thin oil like M1 0w30/5w30/10w30, but it does like a thick 30wt to thin 40wt. I suspect a 50wt will be too much for it and won't flow as well.

But the UOA will tell the true story either way.

 

[Last_Z]

Keep in mind though....this is Texas and 90*F and higher is as normal as 0*F and lower in Ontario. The oil will thin out considerably in high ambient temps. and in a hot running engine.
I definitely believe any lower than ~12cSt in an LS1 and it will show more wear. Now we need to find how thick we can go while getting good wear and decent MPGs. If I don't do it, we'll never know!

 

[buster]

heyjay, great post.

Being the 15w-50 is highly friction modified, I might try it in the summer months. Right now I have 2k miles on M1. I took the remaining qt in the 5qt jug and added a qt of 15w-50 to it for make up oil. Next time, I might try straight 15w-50 just to see how it does.

I still stand by the belief that you match the car with the oil. A good quality 20wt is fine for a car that calls for a 20wt.

 

[Last_Z]

buster,
What car?

 

[buster]

1.8L Corolla. I'm working on trying to get a Dodge Ram with the 5.7 Hemi late this year. I love the Rams with the 20" wheels.

 

[Last_Z]

I might try the 15W-50 in my LS1. It's gonna be interesting to see how it does in it.
Have you noticed a drop in gas mileage Marx?
Thanks

Rick

 

[Motorbike]

Suggest looking into the newly available AGIP PC 5w-40 Synthetic for the LS-1's . $3.91 per liter .

Might be just the ticket

 

[wwillson]

quote:

---

Originally posted by Last_Z:
I might try the 15W-50 in my LS1. It's gonna be interesting to see how it does in it.
Have you noticed a drop in gas mileage Marx?
Thanks

Rick

---

No difference at all.

 

[heyjay]

Mmarx:

You have discovered the glaring contradiction we have in North America when the EPA CAFE Police tell the car maker what oil to use in their motors.

This is for supposed fuel economy "improvements" but when you're discussing 1-3% over the "base reference oil" no driver would notice that.

Applying the mysterious CAFE "new math" which weights theoretical fuel economy "improvement" and applies it over hundreds of thousands of units, the car maker can build CAFE "credits" to minimize or eliminate EPA fines for poor fuel economy.

Yet the same exact motors used in other countries in South America, Africa, the Mid East, and Australlia, recommend MUCH heavier viscosities for summer. Most have a cut-off of +10 C or +50 F for using a 5W-30!

I have a 2000 GMC Sierra and two summers ago I did try Mobil 1 15W-50: the motor was SILENT. No differnce whatsoever in fuel economy.

I have thought of trying to find Mobil 1 Truck & SUV 5W-40, or simply using Mobil Delvac 1 5W-40, but since the Mobil 1 15W-50 is so easy to find and reasonably priced, I'm going back to it.

I believe in matching oil viscosity to temp: since it can dip to -42 where I live, I'm a big fan of Mobil 1 0W-30 in winter. I did try running it into early summer once, and the motor sounded like marbles inside an empty coffee can.

Our LS1-derived Vortec truck motors appear quite sensitive to cold weather oil flow (MRV - Mini Rotary Viscometer values): this is due to the rear sump oil pan, the very long oil pickup tube, and the fact the gerotor oil pump at the very front of the crank has to suck up oil in that long pickup tube.

So the Vortec really benefits from Mobil 1 0W-30, especially in temps colder than -18 C or 0 F. I used to have cold start clatter for 20-70 seconds running Mobil 1 5W-30 in temps colder than -20 F that disappeared when I switched to Mobil 1 0W-30.

FWIW here is the oil consumption report running different Mobil 1 viscosities in my 2000 GMC Sierra truck (Converted to U.S. quarts and miles):

Mobil 1 0W-30 1 quart every 4,200 miles
Mobil 1 5W-30 1 quart every 4,600 miles
Mobil 1 10W-30 1 quart every 6,800 miles
Mobil 1 15W-50 No consumption at all after 5,000

For the Mobil 1 15W-50, I ended the summer test at 5,000 miles as I was scarred of running the heavier viscosity. That was before I started researching motor oils. The motor didn't use a drop of oil, and it was SILENT and MUCH smoother, with no difference in fuel economy. That should have convinced me!

You live in Florida and tow and haul heavy loads? Then Mobil 1 15W-50 is a no-brainer.

Have you taken a peek at the GM Trucks forum? It's sad how a lot of LS1 "Vortec" truck owners complain about their noise and oil consumption, but refuse to try a different oil.

I do believe that GM now states oil consumption of 1 quart every 100 gallons of fuel is "normal."

Scary.

Here in North America the LS1 in the Chevy Corvette has Mobil 1 5W-30 as the recommendation. In the UK, BP recommends using their premium synthetic "Visco 7000" 0W-40 in that same exact motor.

High performance Holdens in Australlia appear to use 10W-40, 15W-40, 15W-50, and 20W-50. In the same exact LS1 motor.

So welcome aboard and enjoy.

Jerry

 

[Patman]

quote:

---

Originally posted by Last_Z:
Keep in mind though....this is Texas and 90*F and higher is as normal as 0*F and lower in Ontario. The oil will thin out considerably in high ambient temps. and in a hot running engine.
I definitely believe any lower than ~12cSt in an LS1 and it will show more wear. Now we need to find how thick we can go while getting good wear and decent MPGs. If I don't do it, we'll never know!

---

That is true! I do believe you'll find a mid 40wt is about the highest you'll need though, you'd probably get better wear with M1 5w40 over the 15w50, so you should try that one after a few runs with 15w50.

 

[heyjay]

quote:

---

Originally posted by Last_Z:
It's official......I'm running all 15W-50 as soon as I finish my ARX treatment. It's fixing to get hot here in TX anyway.....it was 81*F today (eat your heart out Patman....you too heyjay

) and we might have just a few more days of very mild cold and that should be it!

heyjay,
Fortunately, my LS1 never burned any oil, no matter what weight. It did slap a lot though, but I just had GM put new pistons and rings in it and the slap seems to have at least, quieted down a LOT. I'm hoping the 15W-50 will quiet it down even more.
How low a temperature can the 15W-50 be run?
Thanks

Rick

---

Yeah yeah I always think of that when it hits -42. Then in summer I ***** and moan about it being 95 F with the humidity at +80%. I guess I'm just never truly happy unless the temp is at 74 F and humidity exactly at 50%.

Mobil claims the 15W-50 is safe to -35 F. When I had my 4Runner in Salt Lake City Utah, I used Mobil 1 15W-50 year round. A few times it got down to 0 F and there was no problem with startup noise and good oil pressure.

Folks still worry about "wear" in an LS1-derived Vortec truck motor when the stupid thing makes noises and burns oil like crazy using the "recommended" viscosity.

If you're running a 15W-50 or 20W-50 in summer, especially heavy towing, and getting +8,000 miles per quart, you do NOT have wear.

How about the unlucky Vortec owners who are told it's okey-dokey to add 1 quart every 100 gallons of gas? Or that the constant CLACK CLACK CLACK KNOCK KNOCK KNOCK doesn't do any damage? Let me guess, no wear to worry about??

At 1 guart every 100 gallons of gas, why even bother changing the oil? Just keep adding oil!

Just make sure you change your O2 sensors and catalytic convertors once a year.

Jerry