How COULD changing oil brand effect comsumption?

[Stainless]

Hello.

I don't have a specific problem myself, but I just have a general question.

Assuming you are changing to the SAME weight, IE. 5w-30 to 5w-30 or 15w-40 to 15w-40:

I have noticed many posts that read, "I was running XXX oil and had no comsumption issues, but i changed to YYY oil (same weight) and now i have comsumption issues."

How is it possible that a car can consume one oil, but not another, if they are BOTH of the same weight?

Also, Another post I read often is this, "after i changed to YYY oil, i had oil comsumption problems for the first 2 OCIs, but then they went away, and the car no longer comsumes oil."

That one is even MORE confusing to me. How is THAT possible? The oil is changed, there are comsumption problems... and then, using the SAME oil... poof... no more problems.

thank you.

 

[ewetho]

Not sure but have seen it first hand. My Neon eats Mobil1 (has a PCV design issue) and other oil don't seem to see it so much. Why??? I do not know. May be that some oil atomize(mist) a bit easier than others.
Just a guess.

 

[TimVipond]

Some oils of the same "weight" can vary quite a bit in volatility of the oil itself. You can read about the NOACK Volatility test and compare different oils volatility on page 3 at http://www.amsoil.com/lit/g1971.pdf .

 

[sxg6]

I just want to make it clear that even though the oils make have the same weight on their label.. Such as 5w-30, that doesn't mean they're exactly the same. That just means they fit into the acceptable range for that weight.. You may already know that, but i'm just checking.

 

[Blue99]

Some reports of consumption issues are valid - some are just inaccurate observations.

In the case of M1, some engines will burn a quart during the initial 2k miles and then the problem just goes away. The M1 technical people refer to this as "seating", as reported to us by Mickey M.

Some switching from one oil to another could cause temporary sticking in the piston rings do to the switch in additive chemistries.

But I'm convinced, alot of the reports we read, here, are false observations, as some related problem has developed & the owner didn't recognize it until the "new" oil was installed & he/she started to closely monitor for results.

 

[mdocod]

my suzuki swift burned about 1/2 qt of Mobil EP in about 2000 miles after switching to it, then leveled off to it's normal minimal consumption (barely measurable between OCIs). I don't understand the physics behind this, but I have observed it. ARX also temporarily increased consumption on my isuzu (to about a qt every 500 miles), after the cleaning was done it settled back down to it's usual qt every ~1000 miles.

 

[ThirdeYe]

That's weird, ARX didn't make my car consume any oil, then again my car's been very easy on oil since i've owned it. It's never moved on my dipstick at all. Never burned a drop of oil since i've had it

 

[leel]

I'm not trying to hijack this thread here but I had a few questions.

1 How accurate is the noack testing?
2 Could the Castrol gtx really done that good compaired to the others?
3 I wonder why the did'nt have Maxlife or Valvoline ac in the test? (would love to how maxlife did compaired to others)

 

[TimVipond]

Quote:

---

I'm not trying to hijack this thread here but I had a few questions.

1 How accurate is the noack testing?
2 Could the Castrol gtx really done that good compaired to the others?
3 I wonder why the did'nt have Maxlife or Valvoline ac in the test? (would love to how maxlife did compaired to others)

---

1. Should be pretty accurate. It is a simple weigh, heat, reweigh analysis. It also uses standards with known NOACK values. I'd say the test is within 1% accurate. But sample variability of motor oil batches may be more variable than that. The data shown goes to two decimals, and usually the precision of the test is in the last decimal place.
2. GTX did well. Perhaps it uses base stocks and additives with less variability (tighter distillation range with lower percentage of light components).
3. You might be able to get the NOACK numbers from the manufacturer by calling their tech line. If they use ASTM D-5800, the values should be comparable.

 

[Dick in Falls Church]

Some 20 years back, Pennzoil had something out which informed customers that changing brands of oil could cause temporary increase in oil consumption. Best I can recall, their explanation was that the difference in additive packages could cause existing deposits to be dissolved (maybe to be replaced by new?). Over the past almost 30 years, I've seen many cases of oil consumption after changing to AMSOIL, followed by greatly reduced consumption after a filter or oil change. Doesn't always happen-my 1968 Saab 900 used oil at the same rate before and after the change.

 

[Shannow]

When I got my first car, it was badly sludged. I cleaned it out, and ran cheap (recycled) 20w-40. It burned 1 litre every 300 miles, over two short OCIs.

Tried Valvoline XLD, and dropped to a litre every OCI (3000miles)

 

[otis24]

I have a 2005 Dodge Grand Caravan that I purchased new. I was using Havoline and then Motorcraft. It was using 3/4ths to 1 quart of oil in about 1200 miles. I just switched to Penn Platinum. I currently have about 2400 miles on that oil with about a half quart (or less) of usage.

 

[spiderbypass]

I just put redline 5w20 in wife's 2003 accord. She previously ran Amsoil 0w30. I noticed Redline consumed a bit of oil within the first 2000 miles, where I did not need to add any oil to Amsoil until about 5500 miles.

 

[mechtech2]

otis - A guy posted [on another topic] of how PP caused his oil usage to dramatically increase!
So engines must like certain things, and can't abide others!

 

[perryg114]

Interesting, a year or so ago I noticed my 1995 ford ranger using more oil than usual. Usually it burns less than a quart in 10,000 with M1 10w-30. I wonder if that is when they changed their formula. I still run 10,000 OCI's and its still does not need oil between changes.

Perry