Topic: Should I change the oil or not?????

[Fowlhunter]

I was on my way to work this morning and the "Change Engine Oil" light came on.  I currently have 107,??? miles on the ole girl, she's not due for an oil change till 109,000 (Every 5K miles).  I've been running Pennzoil full Synthetic 10W-30 oil.  I just returned from a trout fishing trip in Branson, MO.  I did pull my boat down and back, It's about a 4hr trip and the worse part of the trip (for the AV) is on Hwy 65 between Springfield and Branson.  The ole girl really works on the hills!

What do you think???

Thanks, Fowlhunter

[Main One]

How long do you want to keep your AV?

I run full synthetic and change per the computer telling me when it is time to change.  I don't know the specifics of the algorithm the GM engineers have programmed into these trucks to know when the oil should be changed, although I have noticed on mine shorter intervals (mileage-wise) during the winter months so I believe cold-weather operation in the GM engineers' algorithm is harder on oil.  I would guess that running at higher rpm levels, and possible at higher engine loads at the same rpm levels, could also be in their programming, like you would get from towing would also be something that they use in calculating oil life.

I would go ahead and change it.  It will probably bug the heck out of you if you don't, so just do it and get it over with!

On another note, why the 10w30 (vice 5w30), particularly over the winter?

[Fowlhunter]

Forever!!!

You make very good points.  It's just hard to believe I need to change the oil (Synthetic) with 2K miles to go.   

It will bug the heck out of me if I let it go.  How do you know how anal I am?? 

I've always thought 5W30 was too thin.  I've always run 10W30 year round, right or wrong??  I have never run the 5W30 in her, should I???  I know that's what it calls for but never have.

[FlaBouy]

I've always thought 5W30 was too thin.  I've always run 10W30 year round, right or wrong??  I have never run the 5W30 in her, should I???  I know that's what it calls for but never have.

Now there is an argument in the making....

I am like you and I run 10W30 Mobile One.... Just never got used to feeling comfortable with the thin 5W30.... There is an argument out there that with the orifices in the LS1 lifters, that one would want to stay with the viscosity band that the 5W provides, but I can never get something out of my mind that I read in the book about how the LS1 evolved from an engineering standpoint....

Many don't know that the 5W30 was mainly tested to help provide better fuel economy due to less friction generated by the oil....

Since fuel economy is not my first criteria in selecting my motor oil, I found little other reason to stay with the 5W30 recommendation...

I am sure someone will be along shortly to educate me though.....

[Main One]

It's just hard to believe I need to change the oil (Synthetic) with 2K miles to go.   

I'm pretty sure that the algorithms are assuming that you are using the oil specified in the owners manual, dyno 5w30.  They are not taking into account that you are using a synthetic that may not "wear out" as quickly.  Therefore, do you NEED to change your oil right away?  I would say no, the 5000 mile interval would probably be fine for you.  On the other hand, the peace of mind that you would get from going ahead and changing it is probably worth the price of the oil change.

[Main One]

Now there is an argument in the making....

I am like you and I run 10W30 Mobile One.... Just never got used to feeling comfortable with the thin 5W30.... There is an argument out there that with the orifices in the LS1 lifters, that one would want to stay with the viscosity band that the 5W provides, but I can never get something out of my mind that I read in the book about how the LS1 evolved from an engineering standpoint....

Many don't know that the 5W30 was mainly tested to help provide better fuel economy due to less friction generated by the oil....

Since fuel economy is not my first criteria in selecting my motor oil, I found little other reason to stay with the 5W30 recommendation...

I am sure someone will be along shortly to educate me though.....

Don't have much info to "educate" with here.  I tend to not want to second-guess the engineers on the weight of the oil, although as someone who has second-guessed them on things like air filter, exhaust system, cam, programming, etc, maybe I should rethink that.

I'm no oil expert, but I believe from what I have read, is that the "30" is what is going to be in play for most of our engines use, unless your vehicle is subject to the severe duty of mainly very short trips and spends most of its time warming up.  As I type that, maybe that applies to your AV FB, since you live so close to work.  I've got about 17 miles of mostly 2-lane highway driving, so my truck definitely has time to warm up, even on the coldest of days.

The smaller number, the recommended "5" or the "10" that some prefer, is applicable to how the oil flows at cold start-up.  Given that FB lives in Florida, and his truck doesn't see too much time below freezing, the 10w30 probably makes a lot of sense for him.  Farther north, it is different.  I've seen on my mirror, as well as my IAT logs, sub-zero temperatures.  It's gone for over a week here this winter where we never got above freezing.  As I understand it, this is where having the 5-weight oil is important, getting that sub-zero oil through the engine as soon as startup as possible.

Just my  .

[Fowlhunter]

This turned out to be a very informative and helpful topic!!!

From what I've read this is what I conclude:
It's probably a good idea to change the oil in my girl, (may not hurt to go to 5K?) but she has treated me well!!!!   

Is It a good idea to use 5W30 (synth) in the winter and 10W30 (synth) in the summer?

Thanks guys!!!!!!!

Fowlhunter

[FlaBouy]

Some good reading about all those "Myths" pertaining to oil issues:

Oil myths



"As mileage adds up and internal engine wear increases bearing clearances, it may be wise to switch to a slightly higher viscosity rating to prolong engine life, reduce noise and oil consumption. For example, if an engine originally factory-filled with 5W-30 now has 90,000 miles on it, switching to a 10W-30 oil may provide better lubrication and protection. The thicker oil will maintain the strength of the oil film in the bearings better so the engine will have more oil pressure. This will also reduce engine noise and reduced bearing fatigue (which can lead to bearing failure in high mileage engines)."

[Fowlhunter]

Great reading, very informative!!!!

Thanks again!!!!!!

[FlaBouy]

Great reading, very informative!!!!

Thanks again!!!!!!

What I was getting at there, is 10W30 is SAE rated down to -20* and on older "high mileage" motors get some added benefit from the slightly heavier viscosity from the 10W30....

as far as my build goes, I also pull from the oil pan for my blower so that plays a factor in my particular case...