FinallymyT/A

iTrader: (1)

I was with my friend yesterday at our local auto parts store and like a dummy grabbed a 5.1 quart jug of 5w-20 by mistake, instead of 5w-30. It's valvoline full synthetic, and I also put in a quart of full synthetic Lucas.

I realized the horror of what I had done just as I poured the last of the oil into the engine.

Is my engine going to be okay? I live in CT right now, but I am moving to Hawaii in about a month. Will these temperatures effect the oil?

Or should I bite the bullet and just drain/replace immediately with 5w-30?

Car is 100% stock LS1 with 103K miles.

Spartan7

iTrader: (7)

As long as your oil pressure is good at operating temp (i.e. 10 psi for every 1k rpm, at least 10 psi at idle), you're fine.

FinallymyT/A

iTrader: (1)

Thanks Spartan...I noticed that oil pressure was looking good. I just can't believe I grabbed the wrong jug like that.

1 FMF

iTrader: (1)

I would watch oil pressure at idle when hot especially if it's hot outside compared to what it used to do. I assume at 600-800 rpm idle you have 20 and above, and oil pressure jumps right to 40+ when at 1000 rpm. if it falls below 20 psi at hot idle or lower than what you were used to seeing then find a way to keep rpms higher than idle to keep oil pressure higher, don't operate the engine such that oil temp gets that hot, or change back to a 30 weight oil.

FinallymyT/A

iTrader: (1)

Thanks 1 FMF...I have noticed a 10-15psi increase since the oil change. Running right around 35-40psi. Can this be attributed to the lucasoil. So far no strange noises or knocks with the 5w-20 oil, but I plan on changing it tomorrow for peace of mind. Thoughts?

1 FMF

iTrader: (1)

i'd run it and get your money's worth. it's factory fill in ford and chrysler and ford has said to use it in all older ford engines that called for 5w-30. bearing clearances are generally the same among all engines, nothing magical is happening in there. the only thing 5w-20 will hurt is when it gets hot, compared to a 30 weight it will have lower viscosity and lower pressure, and this will only be at 600-800 rpm idle when the oil pump is spinning slowest and moving the least amount of oil. if the oil never gets too hot, and you never have below 20 psi, you simply won't have a problem.

FinallymyT/A

iTrader: (1)

Thanks y'all.

Just for peace of mind, I changed it today.