heel2toe

iTrader: (41)

What have you seen that makes you think that? Have you ever sent your oil out to be analyzed? I dont mean to sound rude so please dont take it that way. I have just heard that for the most part if your using a decent synthetic tests have come back perfectly fine at 5000 miles.

Personally, I change my oil every 3000 miles because it gives me piece of mind. On the other hand I wouldnt mind spacing it out till 5000 miles if I knew that it wouldnt have a negative impact.

buchnerj

iTrader: (19)

If you are really concerned about which oil you are using and its holdup under some beating then the only true way to see what you have is oil analysis. It will tell you the amount of wear and metal in solution, as well as the amount of detergents or certain elements like zinc (mentioned before) that is present in the sample.

FWIW here is my sample that I sent out to be analyzed:


I chose the Brad Penn 20W-50 Racing oil recommended by Buschur. Yes, I chose it because he recommended it, but I did homework first and double checked it after a few analysis runs. I am almost up to 3,000 miles on the new motor and it is holding strong. The Penn oil has a high Zinc content which I like, and it has held up after many days of torture and even after 1,000 miles of a good beating it still had 10x the amount of active additive left in it. So this oil could have gone for longer, but I will never go over 3,000 miles between oil changes.

apagan01

iTrader: (299)

Synthetic oils do hold up better under heat. and those tests on your stove top are neat. but your oils should never get that hot in your engine. so the test is mute but cute
you sound very poetic over there




i do agree that if one is looking for anti wear additives the place to look for its in Zinc and Phos,,, comercial off the shelf oils use a cheaper additive called Molibdenum it is cheap to get for mass production oils and not always better for your sliding surfaces like cams valvetrain parts.

on the other hand believe me there is plenty test that prove over and over and over that a good quality synthetic will benefit your engines reliability and performance,,,, too much proof out there to even think about arguing this one.

apagan01

iTrader: (299)

94AWDcoupe, said that he has seen that 3K would be the max on a turbo car,,, but the issue i have is that to many oil analysis reports have been through my desk and showing sign of not giving up any time soon.

what some fail to remember is that there are plenty high quality oils out there with great additive packages and detergents that will combat oil's enemy's like fuel dilution, shear, heat.

sparky

iTrader: (1)

Of course, you are right 94. And no one wants to argue with you. Yes, the motor oil in a normally aspirated engine will never get as hot as the oil in my brother's primitive stovetop test. Likewise, the 5 quarts of motor oil sitting in the crankcase of a turbocharged Evo engine will normally not get smoking hot either.

However, it should be kept in mind that a turbocharger's bearings are oil cooled. And yes, under normal operating conditions the bearings in your turbo's center housing will not become hot enough to cause what is called oil coking on the bearing surfaces.

But, when you shut your motor off, the turbocharger becomes rapidly heatsoaked and the temperatures within your turbo's center housing can rise to between 600-700* on the Fahrenheit scale. Unfortunately, at these temps your engine oil will oxidize and form coke deposits inside the center housing.

94AWDcoupe

iTrader: (125)

sparky. my fifth turbo car in a long line of turbos tested your coking theory . I had 20,000 miles on this particular turbo. after long drives I hauled down my street (neighbors dont like me) and shut car off instantly. i never used sythetic oil. i couldnt afford it. I thought turbo timers were stupid. I did change oil in 1500-2500 range. when I upgraded the turbo i took old turbo apart to inspect bearings. There was zero coking. the shaft still nice and clean with just the slightest hint of oil stain.

there are too many factors to determine safe oil change intervals. . power and fuel used are two biggies. meth injection dilutes the crap out of your oil. sending oil to labs is excellent idea. I have never felt need for it. looking at color change and viscosity change is enough for me. if your oil comes out of engine like water its not doing its job. if its black there is lots of carbon in it.

I dont argue a good sythetic is not better than most . I just feel if oil is being contaminated quickly It wont be left in the engine long enough to justify extra cost.

Ted B

iTrader: (6)

A few notes in no particular order ...

- Synthetics are superior for a number of reasons that have been delineated too many times in too many places to rehash here. The difference between them becomes most evident over long term use - something that racing engines with <1000 mile change intervals never see.

- ZDDP is most advantageous for engines running shim/bucket valvetrains and such, and while a certain amount of ZDDP is regarded as beneficial, too high a ZDDP content is detrimental over the long haul - again, something racing engines don't see.

- A recent scientific study showed that certain characteristics of synthetics tend to improve after they've been subjected to stress, which supports longer term change intervals. With conventional oils, it's all downhill from jump street.

- Modern turbos with water jackets have all but eliminated coking issues. Older OE applications with non-water cooled thrust bearing turbos are the ones that tended to suffer accumulation of coked residue with conventional oils.

heel2toe

iTrader: (41)

I find this comment to be the most interesting. It would be nice to determine the sweet spot. This goes back to my other statement that unless I send my oil out and it comes back with a good bill of health, I will continue to change it every 3000 miles.

Ted B

iTrader: (6)

I found that interesting as well. The most important thing I've gathered in my own research is that synthetics' superior resistance to oxidation, sheer, and TBN degradation allow longer service intervals than we've been taught to believe (mostly by marketing), but this is strongly dependent upon the efficiency of filtration - a critical detail often overlooked in oil debates.

heel2toe

iTrader: (41)

I never really considered how long the filter can last. I have tried a couple of different oils however have stuck with the genuine mitsubishi filter because its cheap and readily available.

kyoo

iTrader: (29)

I've been seeing various UOAs from people running the rotella t6.. mainly from mazdaspeed3s and stis, and it actually looks quite good. i might say even better than some of the amsoil uoas i've seen...

discopotato03

Mobil1 Racing 4T 15W50 , sport bike engines work harder than virtually all car engines and can't have the same friction modifier additives because most bikes have the multi plate wet clutch swimming in their engine oil . Better base stock than the automotive type Mobil1 and generally more expensive as well .

When you really like your Evie ...

iseedipp

iTrader: (3)

amsoil ftw, i used to use mobil 1 extended it came out too dirty and runny at 2500 miles. My amsoil sso i feel comfortable running for over 5k miles

nothere

iTrader: (23)

apparently ester based oils are considered better, mobil is a cracked oil

apagan01

iTrader: (299)

reallygood point Ted, filtration get neglected alot. Customers of ours in the Camaro community running stock engines with 600 hp some of them run a bypass filtration system and they are confident enough to run their oil up to 30,000 miles

Like you stated a good synthetis will go forever however good filtration methods must be in place to extract all contaminants, and with todays filtration systems its very posible,