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The New 5W-20 grade - Good or Bad for your engine
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Nonetheless, I agree with you that one needs to be very diligent running this oil too long. Many UOA for 5W20 are coming in A-ok. Mine at 3,250 was "just" A-ok IMHO. I'm running Castrol 5W20 for the 1st time right now. Will be very interested in seeing how it eventually compares to Motorcraft.
I just bought 17 quarts of Valvoline 5W-20, which I'll get to using in a couple months or so.
So like all other generalizations about oil, it really depends...
No dino oil is good for 7,500 miles regardless of driving conditions
Where does your information come from? How often have you seen engines die because the oil was not changed on time?
I've seen many examples where people don't change their oil nearly as often with no adverse effects.
My father, for instance, changes the oil in his car only once a year. That is about 15K miles between changes on average. He's had his car (Mercedes) for about 12 years now, I think, and he's never had any engine problems.
Or take for instance a colleague of mine - he stopped changing the oil of his Maxima, and drove for 80K miles without an oil change (hoping for the car to die so that he can justify buying another one). Finally, he went to a mechanic for some minor problem, and the mechanic changed his oil without asking him. This was because it was totally black. What my colleague does is just add a quart of oil when his OIL light comes on. I think he has close to 150K miles on his car now.
This is all anecdotal evidence, but where is the proof that dark oil, oil over X number of miles, oil whose weight has dropped to X, oil whose viscosity has deteriorated to X, oil whose level of iron has increased to X, etc, will damage your engine? I think your car will die of a number of other causes before the engine gives up. For most cars, anyway.
Also, people who don't change their oil, the most basic of vehicle maintenance operations, usually neglect every other system in the car (fuel filter, air filter, fuel injection cleaning, transmission service). That concept, to me, is insane.
Why would anyone spend good money on a vehicle, any vehicle, then not spend a little more to maintain it? Sure you don't have to follow the dealer's recommendations and have the windshield washer fuild flush service for $69.95 or have your muffler bearings changed, but the norm of 3-5K oil changes, 15-20 trans services, 10K air filter changes, 15-20K fuel filter changes, etc isn't a lot of money for increased peace of mind.
One thing that many folks don't realize is that a good used car manager or experienced consumer can tell if your car has been maintained. I know I cann (I'm an appraiser) and I'll dog the car on trade value accordingly.....
zueslewis - Yes, neglecting your car (as in no oil change in 80K miles) is definitely not a wise thing to do. (Some people may get lucky and get away with it.) But I think people fall into one of two extremes - they either change their oil way too often, or completely neglect their car. I think 15-20K mile oil change interval, even with dino oil, should make most engines outlive the rest of the car.
My father takes very good care of his car. This is because he knows absolutely nothing about cars and brings his car once a year to the Mercedes dealership where he tells them to do everything they think should be done. So his car is well maintained (and I suspect they probably change things way too often in order to get his money), yet by virtue of doing this once per year he ends up changing his oil only once per year. His car must be 12 or 13 years old, by now, and he's been following this schedule since new. He's had no engine problems and I believe this to be the norm rather than the exception, given his maintenance/oil change schedule.
Who stipulates what the limit is, anyway? My manual specifies oil change every 10K miles with dino oil, and I think they are overly conservative.
I am not talking about saving $20. I am saying that 15-20K mile change period is adequate in my opinion. I advocate regular maintenance - by all means change your oil regularly, every 15-20K miles!
I'm in the industry - I get to see cases involving engine failure every day. Still, I don't take an alarmist attitude and change my oil once a week - I also won't let it go to 15-20K because I've seen test results on what happens to regular oil after 4-5K and synthetic after 7-9K - I'd say your old man is a lucky guy with his Mercedes.
bottgers - again, how do you relate oil analysis to engine protection? Let's say the oil has X amount of any substance per milliliter - how do you know if that is adequate/inadequate to protect your engine? And where did you come up with the assertion that after 15K miles the engine oil will be like AFT?
We're here to learn and talk about cars. I'm considered an automotive expert in courts in 3 states, but I learn something here on Edmunds EVERY SINGLE DAY.
You go ahead and do what you want, but arguing about oil analysis, or what it shows, and arguing about oil life, with no concept of what an oil analysis proves, goes to show that you're flying by the seat of your pants and don't understand what lubricants do.
I'll protect my investments - do what you want with yours.
And from reading other import boards, it appears that the Castrol being used by Euro-make dealers is infact the Euro-spec full synthetic Castrol product. Yes, Castrol does make a full synth, they just haven't distributed it here.
There are lots of data elements to examine, and not just the mileage. I believe that many European cars can go a greater distance on synthetic oil because they have greater crankcase capacities.
Generally speaking, if you have a crankcase that holds 10 quarts of oil, you can probably go about twice the interval between changes than say with a crankcase that holds 5 quarts of oil.
But then, every engine, every driver, and even the oil use choose is different, so of course, your mileage may vary.
For example, I'm sure the OTR truckers that use conventional oils are not changing every 3k, or 5k or even 10k miles. I'm sure they go over 10k miles between oil changes. Of course, their crankcase is filled by the gallon, not by the quart, so they can safely do this.
Also, how much make up oil do you add? If you add enough make up oil, you might be able to run it a bit longer, since you are getting some fresh additives.
But I'll agree with those who say the only way you can really know is by doing an oil analysis.
TB
My 87 LeSabre with its relatively low revving 3.8L V6 is probably easier on oil than my SVT Contour that frequently visits its 7K hard rev limiter.
TB
And unless you stumbled across some of the 0w40 made in Germany by Castrol on the store shelves, what you see is the Group3 product.
Semantics aside, for myself, a PAO/ester based product = synthetic and a group3 hydrocracked product = a very good dino oil w/robust additive package.
The point of my last message was to ascertain if sgrd0q's father's annual oil changes, used a regular dino, group3 or synthetic.
I find it very hard to believe a group2 oil can go 1 year and 15K without sludging up. Group3 maybe,synthetic maybe.
I'll find out. I assume the dealer uses what Mercedes recommends. I'll try to find out what oil they use.
zueslewis said: you're flying by the seat of your pants and don't understand what lubricants do
Well lubricants lubricate, I assume.
There is no detailed statistical data - we all are using empirical arguments.
If you take any component in your oil and wait until you reach a certain level before you change your oil, and keep doing so until the engine fails – then you have one experiment. Now do the same, but only wait until the component reaches another level before oil changes. Again record when the engine fails. Repeat for other levels. Now to have a statistically significant result, repeat all of the above a number of times (depending on your confidence interval) .
Then you can tell me how harmful certain element elevation in the oil actually is.
As far as I know nobody has done any such analysis. (This may involve thousands of identical engines running hundreds of thousands of miles.)
Also, I am simplifying by monitoring only one element. If you monitor more - you have more complicated analysis.
The truth is you can only guess by looking at various oil analysis results. And also, it depends on your application - e.g. do you want to get 50K, 100K, 200K miles out of the engine.
I'd explain it, but you'd just argue, so I'll spend my time doing something else.
INKY
it could be ordered if you needed it for an aircraft turbine, I expect
Also, what is "dino" oil?
Stop into the LaBrea Tar Pits sometime: http://www.tarpits.org/
Or maybe I will use 5W-30...
I find this newer view far more plausible than the old.
INKY