Thread: What motor oil do you use and why?

I use mobile 1 because the tv told me to

i used on sale oil in my last 2 trucks. they got a oil change a month, as i did 3,000 miles or more a month, and every other oil change the tires got rotated. cheap oil worked well for both trucks, the 97 was at 175,000 when i sold it, ran perfect, the 03 was at 105,000 also ran like new when i sold it.

crazy part is, the 97 never once threw a cel either, the 03, that ones another story.

Originally Posted by stocker

2008 GP base with 85k miles - I run castrol full synthetic in the recommended weight (10w-40?) and WIX. I'm at about 4k miles on this oil/filter and over 20% on the oil meter; color is a dark amber. I can't say I disagree with those who change out the cheap stuff every 3k. I might roll that way someday.

Don't go by the oil life meter. Its not something I would ever trust. I could go 10,000 miles according to the oil life meter on the "cheap stuff." Its just a guess based on load and mileage.

Originally Posted by SlowNA06

I don't even... Are you some kind of oilbender? How have you come across such wisdom that has thus eluded chemists?

My college instructor who has been teaching automotive for over 40 years. Not to mention common sense. Its called contamination....

But hey by all meens do your oil changes every 10-15k and see what happens.I gaurentee my engine is cleaner than yours.

Originally Posted by Ginseng

But hey by all meens do your oil changes every 10-15k and see what happens.I gaurentee my engine is cleaner than yours.

If you will allow, I am going to /thread this whole oil lifetime arguement.

New GMC Acadia 13,000 miles, still had 15% left to change the oil, so they guy never brought it in... the original ACDelco filter from the factory was on it, original oil when it was built still inside... this is what we found. He said it ran funny. lulz







Somehow... warranty covered, 1 time only, he got a new motor. I said consumer neglect, but it wasn't up to me.

Computers lie, change oil 3-5k depending on what you use and how you drive, for most needs to be at or before 3000miles.

I bet my 3.8 with 158,000 miles is cleaner than that thing.

Originally Posted by stealthee

I bet my 3.8 with 158,000 miles is cleaner than that thing.

I know my 2000 i had with 200k on it was cleaner. Now when i got it it wasnt because the people who owned it befor me thought synthetic oil could go 10-15k miles. The oil was so black and chunky when i changed it. It finnally started to clear up after a few 3k-4k intervals and eventually when i changed the oil it looked almost new. And now someone is driving the car a few towns away a year later.

Originally Posted by Ginseng

My college instructor who has been teaching automotive for over 40 years. Not to mention common sense. Its called contamination....

But hey by all meens do your oil changes every 10-15k and see what happens.I gaurentee my engine is cleaner than yours.

Nobody said to go 10-15k. I said 10k at the most, although I personally prefer 5k on synthetic. One of the Grand Prix's I went to look at had 11,000 miles on it's synthetic oil, it didn't look too bad. I would have guessed around 4,000 miles. It was a dark amber color, but nothing close to what those pics look like ^. That's insane. What oil does GM use from the factory? Also AC Delco filters are about as low quality as you can get. That pic of all of that sludge looks like 13,000 miles on conventional oil. What a way to ruin a good engine. Don't go by the oil life monitor.

I use the cheapest oil and filter every 3000

I used castrol for a long time, tried Amsoil for a bit... I had a problem with the oil disappearing. I know it wasnt going on the ground because at work/home I park in the same place all the time and never saw any spots, undersides are clean. So I know it's burning off.

I recently decided to try out Mobil 1 0w30 full syn, first oil I ever used that did not burn off... or atleast waaaaaaaaaay less than the others, I barely lost any, Im thrilled.

Filter... I used K&N pretty solidly for awhile but my oil always got dirty fast, I switched to Bosch Distance Plus and it stays nice much longer now.

As far as intervals, never listen to the computer, I had this car a year now and Im coming up on oil change 4 based on 3-5k intervals, and my Oil Life Monitor is just now reaching 5% left. I just see a lot of evidence that high intervals arent worth it. Besides, even if the oil is good til 10k or 15k miles (Amsoil claims 25k)... How long does the filter go before it fills and goes full bypass?

And for the weight argument, from what I learned on BITOG... even the thinnest motor oils are too thick at start up to be ideal, and say we're talking about 0w30, 5w30, and 10w30... they're all exactly the same at operating temp, the difference is at start up temp... 0w30 being the thinnest, best flowing... although still thicker than it would be ideally. So why in the world would you use an oil that's heavier than too heavy(10w30) at start up, but exactly the same at operating temp where the problem doesnt exist? I've come to the conclusion that if your motor calls for a 30wt oil, 0w30 is the best choice available, but manufacturers (GM) calls for 5w30 because of availability to the common consumer and pricing even though 0w30 is a better choice. It just tends to be harder to find and cost more.

Originally Posted by FriboRage

Besides, even if the oil is good til 10k or 15k miles (Amsoil claims 25k)... How long does the filter go before it fills and goes full bypass?

That is a good point. If the intervals are going to be extended, a good filter must be used. Going 13k on conventional, let alone using an AC Delco filter is insane. If I were trying to go longer, I'd keep an eye on the color of the oil. If you have an engine that dirties the oil rather quickly, I wouldn't ever go close to 10k miles on oil. Newer engines are burning cleaner, and keeping the oil cleaner longer.

Correct, the break-in oil shouldn't be changed too soon. 13k is insane.

you noobs, there is no break in time for a new engine, its old school thinking, back in the day, the cam needed to be broke in, not anymore if you have roller lifters. most seem to have roller lifters these days.

to add, when you first fired up the engine, the cam was broken in, in 30 minutes when you ran the engine in park @ 3,000 rpm. 500 miles later you would do a oil change. after that, it was go time.

The only thing that needs broken in are the rings.

Even though that GMC runs the new Dexos full syn oil from the factory, they still mate it to a crap tastic oil filter.

I find it even funnier that the oil life monitor kept the owner from changing their oil.