I need help tonight please
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Pro
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I have never posted in this forum - New C6 this summer - thanks for all responses.
If I were to permanently change to 5W20, what would/could be the down side?
By the way, I intend on changing back to 5W30.
If I were to permanently change to 5W20, what would/could be the down side?
By the way, I intend on changing back to 5W30.
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From: Miami FL
2020 C6 of the Year Finalist - Unmodified
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16,'17,'18-'19-'20-'21-'22
At engine operating temperature, the 5W part is irrelevant. The 20 weight is considerably thinner than 30 weight. You probably have not hurt anything if you have not been racing at the track, but please change the oil, and the filter, as soon as possible.
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From: So Cal
I've worked on motors and experimented with different weights of oil for protection vs gas mileage/horsepower for years. Don't worry, but I would change the oil and filter. I would'nt wait 10K miles. Better to protect on any hot extended use periods.
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Originally Posted by clevitekid
At engine operating temperature, the 5W part is irrelevant. The 20 weight is considerably thinner than 30 weight. You probably have not hurt anything if you have not been racing at the track, but please change the oil, and the filter, as soon as possible.
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With respect to ordinary engine wear, the 5W is the important number since it denotes the cold flow characteristic of the base oil, and cold start up is when the majority of engine wear occurs. The lower the number here, the better (within reason).
Using 5W-20 would be like running on 5W-30 that has about 10,000 hard miles on it (the viscosity improvers break down with extended exposure to high temperatures, so the upper number of the oil declines). That's not particularly dangerous to the engine in ordinary highway cruising, but does potentially compromise main and rod bearing protection for performance driving situations. So I'd get it out of there relatively soon if I were you.
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From: Holly Michigan
Originally Posted by blkvette1
And I wonder sometimes how much the power train guys know.
They couldn't even engineer the axles right the first time.
They couldn't even engineer the axles right the first time.
Everyone with an opinion aside: I think most of your oil guys will tell you that viscosity will break down with time, induced by heat, fuel and water. 20 Weight is currently being utilized by several manufactures for improved corporate mpg averages. GM is evaluating as well. But, this is not a candidate due to the variety of driving habits and performance expectations of this vehicle.
20W Souldn't hurt under casual driving. But, if you paid to have your oil changed and they put in 5W20 inadvertantly then have them correct there error.
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From: stafford country, va. Avatar: Me on turn 3 @ Bristol (The World's Fastest Half-Mile)
Originally Posted by shopdog
All 5W oils are the same weight, but have various viscosity enhancers added to give them a hot rating of 20, 30, 40, etc depending on the particular application for which they are designed. GM specifies 5W-30 for our engines, so that's what you should use.
With respect to ordinary engine wear, the 5W is the important number since it denotes the cold flow characteristic of the base oil, and cold start up is when the majority of engine wear occurs. The lower the number here, the better (within reason).
Using 5W-20 would be like running on 5W-30 that has about 10,000 hard miles on it (the viscosity improvers break down with extended exposure to high temperatures, so the upper number of the oil declines). That's not particularly dangerous to the engine in ordinary highway cruising, but does potentially compromise main and rod bearing protection for performance driving situations. So I'd get it out of there relatively soon if I were you.
With respect to ordinary engine wear, the 5W is the important number since it denotes the cold flow characteristic of the base oil, and cold start up is when the majority of engine wear occurs. The lower the number here, the better (within reason).
Using 5W-20 would be like running on 5W-30 that has about 10,000 hard miles on it (the viscosity improvers break down with extended exposure to high temperatures, so the upper number of the oil declines). That's not particularly dangerous to the engine in ordinary highway cruising, but does potentially compromise main and rod bearing protection for performance driving situations. So I'd get it out of there relatively soon if I were you.
it'll work, not recommended but will work in a pinch.
the second number in multi-viscosity weight oils basically represents the 'thickness' of the oil when hot.
tighter tolerances will require a thinner oil, looser tolerances (i.e. higher mileage 100k+) will require a thicker oil.