Oil Viscosity Question
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Teching In
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Oil Viscosity Question So, yesterday i did an oil change on the Camaro. I changed oil with Mobil 1 5000
(10w30) and Fram Guard Filter. Today, she runs warm at stoplights. Is the 10w30 too thick?
Thanks.
(10w30) and Fram Guard Filter. Today, she runs warm at stoplights. Is the 10w30 too thick?
Thanks.
What is "warm?" What's the outside ambient temp?
What oil/weight were you using before?
I HIGHLY doubt a small change in oil weight could cause an engine to run warmer. There's probably another explanation, perhaps just coincidence.
What oil/weight were you using before?
I HIGHLY doubt a small change in oil weight could cause an engine to run warmer. There's probably another explanation, perhaps just coincidence.
Thread Starter
Teching In
Joined: Apr 2012
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Thread Starter
Teching In
Joined: Apr 2012
Posts: 10
Likes: 0
This is my first LT1, so I was thinking that i should've purchased 5w30 instead.
If you look into it, it is possible the 10w-30 could be THINNER at operating temps. Viscosity are a RANGE and a 0w-30 can be thicker at operating temps than a 10w-30. Look up "cst @ 100 C" for each oil and find out which is thicker. That is viscosity at 100degrees Celsius which tells you a lot more about viscosity at operating temp. Regardless though 15w-40 was spec'
d for this engine sent to some places overseas so you concerns about 10w-30 are completely unfounded, hell if you look at the owner's manual it will even say 10w-30 is OK for over 0F temps outside. 5w-30 is spec'd for CAFE reasons not because it is critical to the engine.
Fram filters are bottom of the barrel but that isn't your problem either.
Maybe you knocked a wire for a fan loose or knocked off the airdam pulling it up on the ramps or something else that is affecting cooling.
d for this engine sent to some places overseas so you concerns about 10w-30 are completely unfounded, hell if you look at the owner's manual it will even say 10w-30 is OK for over 0F temps outside. 5w-30 is spec'd for CAFE reasons not because it is critical to the engine.
Fram filters are bottom of the barrel but that isn't your problem either.
Maybe you knocked a wire for a fan loose or knocked off the airdam pulling it up on the ramps or something else that is affecting cooling.
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They say there is no such thing as a stupid question but this comes damned close.
As I had already covered 30weight is a RANGE not a specific measurement.
holy massive amount of vague answers.......look, as 96 said different oils do have different viscositys at different temperatures however the inconsistancies are not extreme to the point where you will find many 0w oils running thicker at temps than 10w oils. However saying that 0w oil will not eventually cause ill effects in an engine that is designed for 10 or 20w oil is very misleading.........oil doesnt flow around a bearing in a perfect circular form as many percieve.......the oil forms a wedge shape inside of the bearing clearance area....this wedge changes shape and moves its orientation in the clearance area depending on where the rod is in the stroke (ie. were the forces are being applied at the time due to crankshaft position and momentum)......if oil is far too thin there is a possibility that the wedge will not be able to form correctly and completely and will also not be able to maintain its shape and hydraulic properties correctly....espically if the pump cannot supply sufficent volume to keep the thin oil pressurized in the clearance area.......will the car run down the track? .........mosty likely yes its a trick guys have been using for ages.....but they go 1320 feet then shut them down........on the street or in an engine looking for high milage i would NOT run light weight oil in an engine designed for a thicker viscosity......also thicker oil will not make a noticable difference in engine operating temperature........YES it will take more to move the oil however the friction caused by this in the pump is neglagable compared to the heat being generated by the combustion of the engine it self..........
Look it up German Castrol Syntec 0w-30 CST @ 100C is thick for a 30weight oil.
Here is a post with a VOA of German Castrol 0w-30. CST @ 100C is 11.78
http://www.bobistheoilguy.com/forums...gonew=1#UNREAD
Here is a VOA for M1 sypersyn 5w-30 CST @ 100C of 10.19
http://www.bobistheoilguy.com/forums...gonew=1#UNREAD
The range for 30weight is 9.3-12.49
I just looked for the most recent VOAs on each oil I have seen M1 test down in the 9s and GC test in the 12s
Some of the best measured results we have for LT1s is GC 0w-30.
IMO the reason you don't see 0w-30 spec'd often is for one it is synthetic only, and you don't see 10w-30 spec'd because they want the thinner startup to reduce startup emissions.
LT1s sent overseas got 15w-40 in some cases and the places that get really hot also tend to get fairly cold at times.
Here is a post with a VOA of German Castrol 0w-30. CST @ 100C is 11.78
http://www.bobistheoilguy.com/forums...gonew=1#UNREAD
Here is a VOA for M1 sypersyn 5w-30 CST @ 100C of 10.19
http://www.bobistheoilguy.com/forums...gonew=1#UNREAD
The range for 30weight is 9.3-12.49
I just looked for the most recent VOAs on each oil I have seen M1 test down in the 9s and GC test in the 12s
Some of the best measured results we have for LT1s is GC 0w-30.
IMO the reason you don't see 0w-30 spec'd often is for one it is synthetic only, and you don't see 10w-30 spec'd because they want the thinner startup to reduce startup emissions.
LT1s sent overseas got 15w-40 in some cases and the places that get really hot also tend to get fairly cold at times.
X2 on that fram being so bad you should even take it off. 
I run 0w40....helps at startup and has a good base weight.
I could see why some guys get confused and maybe scared of going lighter after being at a higher range for a long time. After all if the base weights of all these oils didn't play some kind of an influence on the bearings then 20w50 dino would never raise pressure on an old engine. So some of you guys are off on attacking others for having some caution and questions.
If the engine is a well seasoned over 100K'er on 10w30 it may not be so great to go to 0w-20. Sure it'll work....but still not so great for various other reasons including the wear related clearances.
I run 0w40....helps at startup and has a good base weight.
I could see why some guys get confused and maybe scared of going lighter after being at a higher range for a long time. After all if the base weights of all these oils didn't play some kind of an influence on the bearings then 20w50 dino would never raise pressure on an old engine. So some of you guys are off on attacking others for having some caution and questions.
If the engine is a well seasoned over 100K'er on 10w30 it may not be so great to go to 0w-20. Sure it'll work....but still not so great for various other reasons including the wear related clearances.
