light wt. oils?
Thread Starter
Melting Slicks
Joined: Dec 2004
Posts: 2,687
Likes: 1
From: Manteca CA
light wt. oils?
Any body else using 0/30wt or 0/40 wt. in their Lt-1 or Lt-4?
I have been using Mobil I 0/30 in the Lt-4 for many years and never have had a oil pressure problem at any temp or rpm. I just feel the lighter the better at start up.
Other views?
I have been using Mobil I 0/30 in the Lt-4 for many years and never have had a oil pressure problem at any temp or rpm. I just feel the lighter the better at start up.
Other views?
Safety Car
Joined: Jul 2008
Posts: 3,966
Likes: 4
From: Made In America
St. Jude Donor '10-'11
I use 10w-30 because it's the only thing that the parts store near me has. Don't you need thinner oil in the winter and thicker in the summer? Start up is the most critical time for your car. You want the oil to get to the motor as quickly as possible to keep down wear.
Im no expert and I may be way off. I hope someone more experienced can chime in and point me in the right direction as well.
Anyone who is interested: Bobistheoilguy.com
Thats a wonderful sight about oil.
Im no expert and I may be way off. I hope someone more experienced can chime in and point me in the right direction as well.
Anyone who is interested: Bobistheoilguy.com
Thats a wonderful sight about oil.
Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
Once warmed up 0W30 is no different than 5W or 10W30, they are all 30W oil. The 0W will flow a little better in the cold.
For the last two year I have been running 0W30 in my C4 and 0W40 in my LPE TT C5. Maybe just my imagination, but the engines seem quieter at startup.
For the last two year I have been running 0W30 in my C4 and 0W40 in my LPE TT C5. Maybe just my imagination, but the engines seem quieter at startup.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
"Which 30 Weight Oil Do I Use, 0W-30, 5W-30 or 10W-30?"
AMSOIL:We get asked this question so often that we have included this special page dedicated exclusively to answering the question.
http://www.worldsbestoil.ca/which-30-weight-oil.php
AMSOIL:We get asked this question so often that we have included this special page dedicated exclusively to answering the question.
http://www.worldsbestoil.ca/which-30-weight-oil.php
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
A 5W-30 oil is good for temps from -20 F to well over 100 F. 10W-30 is OK down to 0 degrees F.
Your owner's manual will have oil viscosity recommendations for the engine in the specific model and engine option. For L98, LT1 and LT4 motors a 5W-30 is the recommended viscosity without regard to mileage.
The engineers spend lots of hours determining the best oil viscosity for the corporate engines. The oil companies base their data on a wide variety of engines, climates, and usage. What they say may be suitable is more generic than a specific engine.
If you look at some of the oil requirements for specific cars, they will say that warranty coverage may be denied if the correct oil viscosity is not used. And dealerships will take oil samples for testing if there is any question that a wrong oil weight may have been used in an engine.
Over the last 30+ years, Chevrolet has specifically stated that a xW-40 oil is not to be used in a SBC motor.
Your owner's manual will have oil viscosity recommendations for the engine in the specific model and engine option. For L98, LT1 and LT4 motors a 5W-30 is the recommended viscosity without regard to mileage.
The engineers spend lots of hours determining the best oil viscosity for the corporate engines. The oil companies base their data on a wide variety of engines, climates, and usage. What they say may be suitable is more generic than a specific engine.
If you look at some of the oil requirements for specific cars, they will say that warranty coverage may be denied if the correct oil viscosity is not used. And dealerships will take oil samples for testing if there is any question that a wrong oil weight may have been used in an engine.
Over the last 30+ years, Chevrolet has specifically stated that a xW-40 oil is not to be used in a SBC motor.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
My 96 Owner's Manual says, specifically, "Do not to use SAE 20W-50 or any other grade oil not recommended". The only recommened weights listed are 5W-30 and 10W-30.
It also states that:
"The Corvette engine requires a special oil meeting GM Standard GM4718M" . . . and "However, not all synthetic oils will meet this GM Standard".
Also, "If you use oils that don't have the GM4718M Standard designation, you can cause engine damage not covered by your warranty".
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day parade 20 May 2010!!!
It also states that:
"The Corvette engine requires a special oil meeting GM Standard GM4718M" . . . and "However, not all synthetic oils will meet this GM Standard".
Also, "If you use oils that don't have the GM4718M Standard designation, you can cause engine damage not covered by your warranty".
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day parade 20 May 2010!!!
Race Director
Joined: Jan 2002
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From: O'Fallon Missouri
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Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
What I posted is what "GM" says and recommends. I hesitate to make a recommendation on oil that diiffers from GM's, but occasionally I do especially when a poster's oil pressure light flickers at idle while running 5W-30.
As I understand the OP, his question was directed to those who run zero weight oils. Had he asked what I run I would have said so.
In certain situations, I deviate from what's in the Owner's Manual and even the FSM, but that's just me. Ever check some of the torque specs shown in the FSM, etc.?
For me, recommendations are just that, recommendations; sort of like a starting point. Once I begin swapping parts to those other than stock, many of the stock, factory recommendations fly out the window. Trick is to always know which ones to keep and which ones to dump.
Sorry for any confusion.
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!!
Race Director
Joined: Jan 2002
Posts: 12,263
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From: O'Fallon Missouri
I have also considered running a 40W oil in my LT1. I am running high seat pressure dual valve springs and thought the heavier weight oil might help the lifters stay pumped. Just didn't know how it would affect the tight clearances of the rest of the engine.
