Changing oil not Necessary

[Artan]

Originally Posted by Patrick

I guess you missed this part (emphasis added):

In our Maximum Endurance Test an engine is run at full speed and left to run indefinitely until the oil is compromised and the engine fails using 13,650 litres of fuel, 4 sets of tyres, but only 1 oil**.

And the part where the engine failed after only 148 hours of run time.

The reason it used so much fuel is because they were running at very high power levels, so you can't extrapolate that to how far you could drive your engine.

Read the text again and analyze it carefully. You think 148 hours is something ONLY, at top speed men, this is extreme.

I mean this test is done by the oil company for promotion but think about the things they wont tell you. Read between the lines. Anything else apart from oil could have gone wrong to destroy the engine. There are hidden things that you have to think about.

[Patrick]

Originally Posted by Artan

Anything else apart from oil could have gone wrong to destroy the engine. There are hidden things that you have to think about.

Then don't use this "oil test" to defend your refusal to change your oil.

Originally Posted by Artan

I mean this test is done by the oil company for promotion but think about the things they wont tell you.

Yeah, like maybe they ran the test 4 or 5 times before and the engine blew up at 50 hours, but then they got lucky and got one to run for 148 hours, so that's the one they tell you about.

[jkv357]

That's more of an engine test than an oil test IMO.

If the coolant, oil, and combustion chamber temps are safe and stable, and engine should be able to run at WOT for a long, long, time - no matter what oil is in it. Excess heat build-up is a big problem, that's an engine design issue, but most engines aren't designed with extended WOT running in-mind. That engine was started cold once, and ran directly up to (maybe beyond) operating temp and sat there.

"Extreme Conditions" to me means having a car sitting outside in winter temps, running to the store or work 2mi away, turning it off, starting it up, and driving back. That's what contaminates oil and shortens your change interval.

Most of the time our engines operate closer to that scenario than the "Maximum Endurance Test" one.

[CFECO]

Where did they run the Beemer at full throttle without lifting for a week? Some BMW's come with soft compound tires which last less than 15k miles under normal driving conditions.

[euromodder]

Originally Posted by CFECO

Where did they run the Beemer at full throttle without lifting for a week?

Test tracks like Continental's Contidrome with banked corners allow you to keep running at speed until you run out of fuel, refuel quickly, swap drivers, and get back on track.
Essentially the same way endurance records are done.

Ford has a test track like that merely 50 miles from here.
Lommel - Google Maps

[gone-ot]

...at one time, GM had a banked circular test track at Mesa, AZ, but they sold it (land was too valuable) and now share test facilities with USArmy at the Yuma Proving Ground at Yuma, AZ.

[Artan]

Well, personally I dont need more facts to convince me that I should change the oil. If I change the oil filter every 30 or 50 thousand km that would be enough. If they have done the test spending 13500 liters of fuel at top speed think about normal driving conditions where we normally dont cause stress. Driving at top speed is destructive for your car. I think 148 hours driving non stop (except refueling and changing tyres) is very long time. If i compare my way of driving to this test i can safely drive with the same oil for at least a decade.

Driving at top speed is like a human running at top speed. It wont last much.

[Artan]

Originally Posted by jkv357

That's more of an engine test than an oil test IMO.
If the coolant, oil, and combustion chamber temps are safe and stable, and engine should be able to run at WOT for a long, long, time - no matter what oil is in it. Excess heat build-up is a big problem, that's an engine design issue, but most engines aren't designed with extended WOT running in-mind. That engine was started cold once, and ran directly up to (maybe beyond) operating temp and sat there.

Most of the time our engines operate closer to that scenario than the "Maximum Endurance Test" one.

If they tested the engine why do they say; "until the oil is compromised". (perhaps they changed 3 or 4 engines before the oil was compromised in the test at 148 hours (completely 148 hours with 3 or 4 engines with same oil!)) who knows!?-thats why you have to test it yourself.


"Extreme Conditions" to me means having a car sitting outside in winter temps, running to the store or work 2mi away, turning it off, starting it up, and driving back. That's what contaminates oil and shortens your change interval.

This theory i dont really believe it. They say so but as soon as you turn the car on the oil will be heated up, small amount of water perticles will be removed (evaporate). Although water does not mix with oil but even if it stays in the oil that is a very small amount of it. That is almost zero. If huge amount of water or coolant will mix with oil then you have a serious problems and need to replace teh oil with new one. Oil does not allow metal to condense water. The walls of engine are sealed by oil so even if water particles mix with oil that will not present a danger for the oil.

[jkv357]

Originally Posted by Artan

(SNIP)This theory i dont really believe it. They say so but as soon as you turn the car on the oil will be heated up, small amount of water perticles will be removed (evaporate). Although water does not mix with oil but even if it stays in the oil that is a very small amount of it. That is almost zero. If huge amount of water or coolant will mix with oil then you have a serious problems and need to replace teh oil with new one. Oil does not allow metal to condense water. The walls of engine are sealed by oil so even if water particles mix with oil that will not present a danger for the oil.

That's another oversimplification and not true.

You will get condensation on the internal parts of the engine that will get mixed into the oil (ever seen milky tan-colored oil?). That moister will sit there until the oil (not the coolant) reaches a temp high enough to evaporate it - it takes a while. Just because the car's (water) temp gauge shows operating temp doesn't mean the oil is up to that temp. Reaching an oil temp high enough to evaporate the moisture takes much longer than bringing the water up to the same temp.

On cold start-up you will also have a rich mixture that can't burn completely. Unburned fuel and acids from incomplete combustion find their way into the oil.


Jay

[UFO]

Originally Posted by Artan

Well, personally I dont need more facts to convince me that I should change the oil.

Pesky little things.