Topic: 5W20 wrong oil?

[Revrent]

Just did my first oil change.  Found out the dealers were not putting in synthetic oil in the previous changes.  While I was putting in the new oil I noticed that I was putting in Mobil 1 5W20 instead of the 5W30 that was recommended.   I did a search of the web and found that there was a wide variance of opinions. 

What is your thoughts?  Should I change the oil to the recommend one or wait till the next oil change?

God bless
John

[Sly Bob]

Thoughts vary on this as you know. Personally, I would be changing it and if you are concerned about it that might be the best course of action. May well be okay until the next change though but I wouldn't wait until the oil life monitor said it was time.

If it's hot there I wouldn't wait.

[Helios]

Simple question to ask yourself is, "Is it worth fudging up an engine for $40 worth of material (synthetic oil + filter)?" I think you'd be fine if you decided to leave it in there unless like Sly Bob said, if you were in a hot environment. I know that I'd be changing it if I made the mistake that you did. My 2 cents...

[POS VETT]

It's probably ok if you live in an area with a very cold winter and your Kappa is naturally-aspirated.

[Sol Asylum]

The 5W part is a cold number where as the 20 or 30 is rated at 212F or normal engine operating temp.  So it doesn't really matter how cold it is if your engine ends up at normal operating temps you have the wrong oil in it.

[POS VETT]

Engine oil temperature in my CTS-V is lower in the winter than in the summer for the same drive. Presumably the viscosity of 20 weight in cooler temperature would be about the same as 30 weight in the summer.

[tazz]

My engine never reaches 212.  Always 193-198 hot or cold even at 11 degrees.

[Sol Asylum]

Coolant temp or oil temp?  There can be a big difference between them.

[tazz]

Actually monitor both and they are always within 5 to 8 degrees of each other.

[tazz]

Also coolant always reaches temp before my oil about 4 minutes ealier than my oil.

[tazz]

When cold like it is now anyway.

[tazz]

DashHawk will monitor both.  Now if I constanly pushing the engine the oil temp does vary about 15 degrees hotter but comes down rather quickly.

[elff]

What kappa do you own?

My redline has an oil cap that has mobil 1 right on it.

[Graywolf]

Make the dealer change the oil free, its their mistake.  It takes 4 or 5 min for my oil temp to catch up to the water temp. Definitely change it