How do they do it

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Ok so here is th link https://mobiloil.com/en/article/why-the-...lts-mobil-super

Mobil runs some cars 100,000 miles using 25,000 mile oil change intervals with a 1,500 lb load and at least 1 qt low and they get no sludge or damage. On the other hand we all hear about how this car and that car were sludged up running 5,000 mile oci. Or we here valvoline say you have to change your oil before 4,000 miles. How does an engine not sludge up with that type of service and or how then can we even be afraid of running a conventional oil for 10,000 miles or more? Just looking for some thoughts from this test. I guess it's all dependent upon how your car treats oil?
 
I don't know how they do that. But, I would like to know how many cold start and stop cycles they did during those 25K mile OCI's. If they ran that car steady at 55 mph for a couple of weeks under those conditions, I wouldn't call that severe. Now if they accumulated those same 25K miles in 4 mile trips every 1-2 hours over a year's time, then that would truly be severe.

Lugging that 1500 lb load around might actually be good for the engine causing it to run hotter. And it's the transmission that might show more of the wear and tear. As it is, I took the advice of Shannow and others and now run it at 2,000-2,200 rpm (3rd gear) to get it warmed up more quickly.
 
In my opinion distance travelled (mileage) is one of the worst measurements for determining when to change your oil.
I believe engine hours is much more relevant. You will notice that not many professionals change their oil based on distance travelled. Race cars, heavy industrial, earth moving machinery, and these days even trucks more often than not change oil based on engine hours. Every contractor with OTR trucks that I know changes oil based on engine hours now. Every professional race team I have known changes oil based on engine hours.

On a test stand with the engine set to equivalent vehicle speed of 60mph then 25,000 miles is only 416.7 hours. Well below a standard 500 hour OCI
 
I agree that these test methods show little in real life performance of oil and sludge. It looks like constant running. The easiest miles and cars you see with high mileage are highway miles. I believe that's why we see company vehicles with 200,000 to 300,000 miles and we push to get 150,000 out of personal vehicles trouble free. Its because they get started in the morning and run all day. Stop and go and shut off and start up with oil not to temperatures to burn off id when all the gunk starts. The Castrol tests are even more stupid with simply holding a engine full blast till the one with their oil blows up. Not much of the test most of us would really benefit from.
 
Apples and oranges OTR hours aren't equivalent with a sedan used for short runs around town. If it was mostly highway though..
 
Originally Posted By: Jake777
Ok so fill me in. Could I just switch to 500hour oil change?


My opinion is you need a maximum engine hours, and maximum sump hours. The shorter of the two is used to change the oil.
Most construction companies that I have worked with change oil at 12 months if engine hours aren't reached. This only happens during storage usually with vehicles such as soil stabilizers that may not be used for extended periods of time. They are serviced before going out if they have been sitting for too long. Regardless of how many engine hours since last service.
 
I can see this as a possibility, 1ZZ-FEs have a lot of VARNISH (from lack of maintenance) but never any "sludge" that I have seen, in fact the only engine I saw any sludge in was the 2zz-ge with two dime-sized "sludge" pieces.

done 60+ 1zz-fes, I can see mobil super easily go 15k, I currently have 12k on Valvoline Maxlife NextGen 10w40 for break-in oil change after a rebuild, engine got cleaner then before and absolutely no oil loss at the moment.

Honda 4 cylinders are notoriously easy on oil as well and I have experienced this as well, my first car I did 5k to 30k OCI on walmart dino, engine never ever had any oil issues.

I can't speak for any other engines though.
 
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Constant running in the 2000-2500 rpm range are ideal conditions. Shut down the engine let it get cold and restart it frequently and those test results will go right out the window.
 
As someone that used to run oil sludge tests, I can give you my take on this...

There are a couple of industry standard sludge tests. In the US, you have the Sequence VG test. In Europe, for a long time, we had the Mercedes M111 test and now have the more up-to-date M271 test. If memory serves, the VG runs for about 216 hours. The Mercedes tests run out longer to around 250 hours (I forget the exact number).

The thing you need to understand is that getting engines to sludge up (even when you want them to!), is not easy. Take a standard engine on standard fuel running under normal conditions and it can run for ages and ages without it sludging up.

To induce sludging on the standard industry tests, the trick is (a) to use a 'special' fuel and (b) to run the engine very cold such that some of the special fuel gets into the sump. They have to do this because it's the grot in the fuel that causes to oil to ultimately destabilise.

When you know all of this, the Mobil story is easy to understand.
 
Originally Posted By: 69GTX
I don't know how they do that. But, I would like to know how many cold start and stop cycles they did during those 25K mile OCI's. If they ran that car steady at 55 mph for a couple of weeks under those conditions, I wouldn't call that severe. Now if they accumulated those same 25K miles in 4 mile trips every 1-2 hours over a year's time, then that would truly be severe.

Lugging that 1500 lb load around might actually be good for the engine causing it to run hotter. And it's the transmission that might show more of the wear and tear. As it is, I took the advice of Shannow and others and now run it at 2,000-2,200 rpm (3rd gear) to get it warmed up more quickly.


Absolutely. That is an ideal operating condition for an engine.
 
Originally Posted By: Toaster_Jer
On side note,I have a question for you? Can a person create a sludge problem or any other situation by mixing two or more different motor oils say from left over oil changes?


In my opinion, mixing any fresh engine oil with any other fresh engine oil will never result in a problem. Obviously if you mix a full synthetic top tier 0W20 with an full mineral cheap-as-chips 20W50, you won't continue to get the performance of the better oil; it will be somewhat worse. However if both oils pass the Sequence VG sludge test, then the mix will pass too.

Most engine oils will contain 90%+ base oil of some description. They're all perfectly miscible with each other. All of the additives that go into engine oil have to be oil miscible/dispersable otherwise they couldn't ever be used.

Hope that helps...
 
Yes. Taxis are not as much "severe service" as the manuals would have us believe. There are few cold starts. The engine and oil are always at operating temperature. That does wonders for an engine, and for oil longevity.
 
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