Thread: what kind of oil?

Well my free oil changes are done since I have more than 36k on my car so, I am going to change my oil on my day off tommorow. My question is should I stick with the cheap ol' gm oil from the dealership, or is there a better option that would work for me. Could I just switch right over to a good synthetic? What do you guys run, or suggest that I run?

I have a 2004 gtp comp-g if that info matters to you guys at all.
-steven-

Here is a awsome subject...
I think i'm going to be starting to use Mobil 1
as i have so many miles on the car...

I have read so many studys on this it is sickening
and not sure were to weed out the B.S. of the marketing
and the truth...
Q is supost to be the best,
Mobil 1 is supost to be the best ect...
I don't know to be truthful so will book mark this thread for sure...

Thanks John

To weed them out, look at the ASTM test data:

TBN
Viscosity
4-Ball Wear test
HT/HS
Pour Point
Noak Volatility

Just to name a few that I can think of. Be sure they not only list ASTM test number but also the test conditions. For example, the four ball wear test might say something like: (ASTM D-4172B: 40 kgf, 75°C, 1200 rpm, 1 hr), it gives you the test number, the pressure used, temperature, rpm and time. If it doesnt give you all that they likely didnt run the test or its not looking good for them in the results.

The ASTM are industry standardized tests that each oil manufacture subject their products to. Compare those and you can get a good apples to apples comparison.

nothing but Mobil1 here as well

I use Royal Purple, Castol Full synthetic and Amsoil...just because.

Steven I can't believe you opened this can of worms.

Whatever you do, I wouldn't go to the dealer to buy your oil. They will overcharge you.

If you want the best, I would say to run a full synthetic race oil. Something like Royal Purple. If you want good oil, run a Mobil 1. If you want just okay oil, goto walmart and buy the cheapest oil you can find.

For me, since I drive 600+ miles a week, Valvoline from Walmart works just fine for me and is auctually cheaper. And considering how well the 3800s are built, I worry more about the other parts of my car going bad before my engine taking a dump.

I've used nothing Pennzoil in all my vehicles. High mileage 1030 in girlfriend's protege, full syn platinum 1030 in the regal, and 1030 reg in GP. My dad's previous car used pennzoil since he got it (drove it for 10 years) it's a 1989 Park ave. When I took the front cover off to replace the magnet on the cam gear I put a new oil pan gasket on it too. I looked up into the cylinder walls and crank etc, and everything was the color of new metal. My friend also uses pennzoil and put 268,xxx miles on his 93 Ciera 3300 then the frame rotted and the driverside trailing arm broke away from the body. That engine fired up perfectly and it got 34mpg freeway driving around 70mph.

Zef_66 makes a valid point. How many 3.8's have had oil related failure besides the coolant in the oil spun bearing issue? As long as you change it as you should any would be fine.

One note one oil though. A couple of years ago after having done a few small mods in particular the 180* drilled t-sat, I evenually tried Royal Purple for the first time. I drive the same path to work everyday, and back then my focus was on gas milage, as in I checked it everyday.
Got home from work, changed my oil and put in the RP. Next day about 3/4 of the way to work I threw a P0128 engine temp code. Hmmm, the engine must be running a little cooler since I hadn't set that code before. On that same day my mpg went up 2-3 mpg. I've never had an oil make a noticeable difference like the RP. I had been running Mobil 1 up to that point. Let me see if that post is still available from New Impala . Is the RP good for your engine? I have no idea.

found my post from 9/23/05

FWIW. I watch my fuel milage quite a bit....it may be a sickness.. Anyway I've never gotten better than 28.1 MPG driving to work in the mornings. That's driving right at 65 and pretty much staying out of the boost. Last weekend I changed oil and filter to Royal Purple 5W30 and oversized K&N filter. This morning I decided to drive the speed limit (tried to stay just under 70mph), stay out of the boost as much as possible and wound up getting 31.7 MPG.
This oil must be really good or I've all of the sudden become a better driver. It kind of freaked me out when I started pouring in the first qt.. It was late in the evening, the lighting in my garage isn't that good, and the oil looked very dark. I shined a flashlight on the next qt I poured in....quess what...that schtuff is purple...who would have thought!

Update! I had my PCM adjusted to match my 180* thermostat which worked fine even though I think the programmed fans settings were set to come on at too low of a temp. That was my fault and I need to have it adjusted again to the proper temp range. Any who, now that I'm using the Royal Purple the SES code of P0128 (one people get using a 160* thermostat) is being triggered. I'm wondering if there is actually enough friction reduction that the engine is running a degree or two cooler and setting the code.

I don't know but im gonna use royal purple for my next oil change, which is coming up soon again. It seemed like it was last week that i did an oil chnage. Im gonna use a k&n oil filter and ill be all set.

The one thing negative I've heard about RP, besides the price, is that it's not good to use in a car that sits for extended periods of time. Something aout an acidic compound. I'm not sure where this came from, but that's whats been said. My car doesn't sit for weeks or days at a time so for me it doesn't apply.

Yea same here, it may sit in the garage for a day at the most, but that boost gauge is always in action :-)

You are correct, there have been no lubricated related failures I am aware of on a 3800 and indeed I know of very few on any platform. It is a rare thing indeed.

That said, Im going to take exception with the statement that as long as you change your oil, you'll be fine. PLEASE PLEASE dont take this as an attack, bash, or anything like that, its nothing more than just a friendly debate, so please dont let it become anything more than that.

You are correct in that if you change you're oil on a regular basis that you should be fine, but there are other factors that come into play more than just changing the oil on a regular basis.

1. City Driving

Your maintenance practices change drastically if you do nothing but short trip driving versus all highway driving. If you drive all city, stop and go, short trip driving then you are going to have to either change your oil more frequently or use a much more robust oil.
Short trip driving promotes condensation, thickening of the oil and rapid additive package depletion. Your Oxidation and Nitration will usually get pretty high on short order. Another issue is fuel dilution which thins out the oil in a hurry and drastically reduces motor oils ability to lubricate properly and maintain boundry layer protection.

As should be expected, if this remains unchecked or not dealt with it will most certainly result in significant wear increases and drastically shorter engine life.

Short trip driving is usually defined as driving less than 10 miles or not getting the fluids up to operating temperature for at least 15 continuous minutes.

2. Highway Driving

All highway driving is much easier on a motor oil and therefore you can actually extend your drain intervals out some, even on regular petroleum motor oil. As well it helps to minimize fuel dilution. If you have a fuel dilution issue and all you do is highway driving, you have a major issue.

It also gets the engine and fluids up to temperature for prolonged periods of time and therefore can evaporate any moisture or fuel that gets into the oil. What you have to watch out for more with all highway driving is the oils ability to sustain itself exposed to normal operating temps for sustained periods of time.

I have personally went 15,000 miles on my current Grand Prix without an oil or filter change. I used oil analysis to make sure the engine was doing okay, but I made it 15,000 miles before my LIM started leaking and I had to dial back the change intervals to combat the effects of the coolant getting into the oil. But because of the amount of highway driving I was doing at the time, coupled with the filtration I have, I was still able to manage 7 - 8000 mile drain intervals and I have the oil analysis results to show for it.

3. Infrequent driving

If you do not drive your car frequently, even if its for all highway or all city driving you still need to change the oil with some regularity. After you shut down the engine, moisture can develop and make its way into the oil where it reacts with combustion by products and starts to break down the oil and can even attack the metal surfaces. Your engine can actually rust from the inside. In this case, there just isnt any option other than to use really good filtration and to change the oil more frequently.

So while changing the oil on a regular basis is a good maintenance practice, a better option is to understand your driving conditions and selecting a motor oil that meets those particualar needs. My wife drives maybe 10 miles total a day. We live not a half mile from where she works. But even with that, undertanding that those conditions affected the engine differently than my 70 miles of driving a day allowed us to keep her car around for 12 years and right at 200,000 miles on it before it was deadlined and not because of an engine or tranny failure either.

There is more to motor oil and just changing it regularly. You have to understand which motor oil works best in your engine with your driving conditions and style. You could take two identical Grand Prixs that are the same in each and every respect down to how they are driven, how far, how often and so on and it is likely one particular motor oil will work really well in one engine and have lesser results in the other.

The goal of any maintenance program is to maximize engine life while minimizing maintenance costs. And just changing the oil on a regular consistent basis doesnt take that into consideration nor may it be the best approach for all situations.

You are a bobistheoilguy memeber aren't you? I am fwiw.

All of what you said is accurate, but as stated you need to use the right spec oil for your vehicle and change as needed based on your driving habits and location. What I've noticed over the years is, those with 100,000 miles+ without engine problems on their vehicle have one thing in common. They change their oil and filter and do regular maintenance on time. The oil of choice seems not to be the constant.

Hopefully this did not come off as anything but adding to the discussion.

i have used kendal synthetic oil , mobil1 and quakerstate synthetic but i do want to try the royal purple from everything i have read .

Yea im gonna give royal purple a shot, ill be sure to post an update after i change the oil using the Royal Purple

Nope I dont take it that way. So your fine. And yes, proper spec oil is important.

However, we do come back to regular maintenance on time. And its that statement that leaves it all open. What is 'On Time Maintenance'? Is it one that observes some pre-defined mileage or time set by someone with other interests than engine longevity? Or is it one that observes the affect of the program in place and whether or not that 'On Tiime Maintenance' is really On Time or can it be stretched out and reduce cost or can a different product be used to reduce overall engine/equipment wear.

So I see your point but I think its that 'Change it on a regular basis' or "Maintenance on Time' that leaves most confused and how that is really defined. Do we take the operators manual for Gospel? Do we accept the recommendations that the oil producer suggest? Or do we take a more direct approach and listen to what the engine says because, after all, its the one affected most directly and has the most direct information.

And dont neglect the environmental impact a good maintenance program can have, ESPECIALLY when you start reducing the amount of waste oil and the impact that can have on ones wallet.

And for what its worth, I am a member of BITOG, but I do not frequent there very much at all anymore. I choose to do research and learning at other places and with other sources.

I do my oil changed like every 2,900 miles, i like to take car of my baby.

I'm feeling am Amsoil vibe? am I close? fwiw I like Amsoil or the idea behind it? It was the enviromental thing that gave me the vibe...that and I just realized your sn, could be anything, but...