synthetic oil question

[dirtboy]

Originally posted by: sao123
And now these messages from your actual local mechanic.

At one point in time, it was necessary to wait 1-2 oil changes for break in, before switching to full synthetic because it would cause the engine seals to leak.
Synthetic oil has been reformulated within the last 5 years to eliminate this problem.

Several cars now actually use full synthetic direct from the factory.
Cadillac CTS, XLR, SRX and STS
Chevrolet Corvette
Dodge Viper
Mercedes-Benz
Mitsubishi EVO
Pontiac GTO
Porsche

Chrysler Crossfire

 

[0roo0roo]

Originally posted by: Sundog

Originally posted by: 0roo0roo

Originally posted by: Eli

Originally posted by: yougotdeals

Originally posted by: Eli

Originally posted by: yougotdeals
I started using long life Royal Purple oil, and it's worked just fine in a car with 80K miles on it. I usually use Wix, but will use Fram filters too. Fram has really stepped up their quality in recent years due to the fact they were exposed years ago (their filters were junk).

They are still junk. Cardboard end caps. 'Nuff said.

Fram's higher end filters are better, but there are still other brands that are higher quality and about the same price.

The Fram I cut open did not have a cardboard end cap. But if you want to play it safe there are plenty of other options out there.

Yeah, their ToughGuard or X2 or whatever filters are more reasonable in their construction.

There was a bit of bad internet publicity for them a couple of month back, when some people on a truck message board were cutting open their fram filters, only to find the media burst...

wallyworld filters are 2 dollars and supposedly better though

You get what you pay for. Go ahead and put in a $2 oil filter...don't come b$tch when something happens. I'll be sticking with the AMSoil or Hastings filters.

http://www.oilfilterstudy.com/
works better than fram

 

[Slickone]

Originally posted by: Eli
Physics. All else being equal(primarily surface area), the filter that flows the most air will also flow the most dirt.

What if you had a filter consisting of a metal sheet with just a few small holes or strips cut in it. Wouldn't it let in more dirt, yet aerodynamics (flow) would be worse, than a paper or gauze filter?

Maybe true (but has it been proven?) for paper vs. gauze, but I dont think your statement should be used so generally. I bet years ago someone said "For something to be stronger than this [whatever], it has to be heavier." Yet with technology, we have composites, etc.
And I'd bet with technology, one day they'll come out a new filter material that flows much better than, yet filters as good or better than, paper or gauze.

 

[Eli]

Originally posted by: Slickone

Originally posted by: Eli
Physics. All else being equal(primarily surface area), the filter that flows the most air will also flow the most dirt.

What if you had a filter consisting of a metal sheet with just a few small holes or strips cut in it. Wouldn't it let in more dirt, yet aerodynamics (flow) would be worse, than a paper or gauze filter?

Maybe true (but has it been proven?) for paper vs. gauze, but I dont think your statement should be used so generally. I bet years ago someone said "For something to be stronger than this [whatever], it has to be heavier." Yet with technology, we have composites, etc.
And I'd bet with technology, one day they'll come out a new filter material that flows much better than, yet filters as good or better than, paper or gauze.

Well, it's the point I'm trying to get across... You're right, it is a little more complicated than just surface area... there are quite a few other things at play, but still... we're still dealing with physics here.

With filtration, it's always a tradeoff. Doesen't matter whether you're filtering a viscous liquid like oil, or a gas like air.

If you need high flow rates and high filtration, you use a filter with a small pore size and a large surface area.

If you need high filtration and low flow rates, you use a filter with a small pore size.

If you need low filtration and high flow rates, you use a filter with a large pore size.

There just isn't any way to get around this. Obviously, you aren't going to get much flow through a filter that blocks everything.

 

[0roo0roo]

site i listed has flow rates and pore sizes

 

[KingPhil]

Ask "notfred", he's apparently the all powerful motor head...

http://forums.anandtech.com/messageview...atid=38&threadid=1610844&enterthread=y

 

[Slickone]

Originally posted by: KingPhil
Ask "notfred", he's apparently the all powerful motor head...

http://forums.anandtech.com/messageview...atid=38&threadid=1610844&enterthread=y

Having worked in the biz myself, there are many a fine mechanic out there that don't know jack about, nor do they care about, the best air and oil filtration. Many use what their dad told them was best.

 

[yougotdeals]

Originally posted by: radioouman

Originally posted by: yougotdeals

Originally posted by: Eli

I would never pay any attention to any "Oil change light". It's an idiot light at best.

That's sort of what I was thinking.

DO you know what the warning light actually does?
It takes three inputs: Engine temperature, engine speed (RPMs), and mileage since the last time it was reset and makes a good guess about when the oil should be changed.
It doesn't actually check the oil! You could be 2 quarts low and the system would never know. If you forget to reset the light, you are screwed.
The interval will not change if you use the best synthetic vs. the worst dino.

Yeah, I know. I was in agreement that I wouldn't trust the change oil light on any car.