There are lots of threads that become hijacked and devolve into arguments on oil change intervals and the use of low octane gas in a car that specifies high octane of 91 or better. I figured, why not start one where that is the topic.

I change my oil at a maximum every 5K miles and only use 93 octane fuel. Not because I enjoy spending more money, but because I believe it's better for the longevity of the engine. My thought is that the money saved in the short term will be saved in the long term with not having expensive repairs. I also prefer to keep my cars a long time. For those that lease or trade their car in after 2-3 years and prefer to abuse their engine before getting rid of it saying it's no longer their problem. Well, I have nothing to say to you.

I'll admit that I have no expert knowledge which is why tend to rely on other experts who have no skin in the game other than to help their fellow man. Here is one who explains the reasons behind shorter oil change cycles and use of premium gas in a high compression turbo engine. He is certainly not the only one, but a good explanation. You have to watch to the end for the octane discussion. He also has a lot of good advice on how to properly care for your turbo charged engine. I know this will not convince many or any of the people that save money but using low octane and change oil every 10K or more, but it explains why I and others do not do these things

 

This quote from your post is the problem with your question:



Once you assume the conclusion, that changing your oil as the manufacturer recommends every 10K miles is an abuse, then you will get your answer, change oil every 5K miles. This is the fallacy you have fallen into: assuming the conclusion.

Others then could correctly say that if changing every 5K miles is better than every 10K, then why not change every 2,500 miles like we did in the good old days.

In another post I wrote that there is no way to answer your question of whether changing oil every 10K will lead to an engine failure in 15 to 20 years, 150,000 miles and because there are so many variables that even if you change your oil every 2.5K miles or 5K miles you still might have an engine failure.

My dentist advises to brush teeth twice a day and at least one of those times for 2 minute and to floss once a day. I know people who double that and still have dental problems. Would those people then not have dental problems if they brushed 4 times a day and flossed twice a day? Nobody knows.

I also know people who never brush their teeth and are without dental problems.

 

Just watched the video which as you correctly state is informative:

• At 9 minutes he gets to the crux of the question: How you drive: If you expect your 4 cylinder 2 Liter turbo engine to perform like a naturally aspirated 4 liter V6 or V8 you will have to drive the engine hard, which in order to produce horsepower means high RPM's. The key to remember is that the higher the RPM the greater the speed of the Turbo. At low RPM's the turbo "boost" is minimal. As RPM's increase the boost becomes greater. The use of the Turbo to produce performance is what is going to wear out the Turbo and possible use oil.
• Premium octane: Again whether or not damage will happen depends on two things: how hard you drive your car and whether your car is equipped with electronic pre-detonation - which almost every car is so equipped. As I posted, electronic ignitions that adjust for pre-detonation will reduce the horse power. But if you drive modestly, this loss of horse power you will never notice.

I have posted that I never floor my car even when passing, never race from a stop light and do not pull anything behind. I never stress my car so the Turbo hardly every comes into play. I also have posted that if you race from stop lights, drive you car at autobahn speeds, in excess of 100 mph, drive hard or pull something behind you, that you probably should be using premium gas.

As to oil consumption on my car, the V6 twin turbo, I periodically check my oil. I have never had to add oil between oil changes which I do at 10K miles. Again I never drive hard and never stress my engine.

Finally, the author is in the business of servicing cars: the more often you service your car, the more money he makes, so it is to his financial benefit that service is done as frequently as possible, so you must admit that he is not totally neutral.

As I posted above more service is better, (but each time you remove a screw from the oil pan and replace an oil filter, there is wear on the groves, which can cause leaks and other problems) but the question is not better but necessary.

My Ford calls for an oil change every 7,500 miles. The dealer says very 3,000 miles. Does the extra money he gets from doing the oil change twice what Ford recommends and the extra income he derives from the oil change, can that possible influence his recommendations?

You decide.

Remember the old adage:

 

Actually, it's you who are assuming. I simply made statements regarding people who abuse their car with the mindset that when the car is 3 years old, they will get rid of it and any long term damage they may have caused will not be their problem. I never said that following the manufacturers guidelines is abuse. All I am saying is that there are reasons the the manufacturers guidelines are not in a long term owners best interest and the video covers some of them.

What I find curious is that while you are so keen on saying follow the manufacturers oil change interval you completely ignore the fuel guidelines on minimum octane. All because you cannot notice an issue immediately or even days later. In 10 years and 120K miles when the piston cracks or the turbo fails, nobody will know that a poor maintenance schedule or low octane fuel may have contributed to that failure.

Anecdotal evidence you sited has no usefulness in this discussion. There are exceptions and edge cases to nearly everything. At the end of the day nobody is right or wrong here. We are all basing our decisions on what we perceive to be of value to us. I place value in taking care of the things I have in an attempt to make them last a long time. You had asked me in another thread why I believe the oil should be changed more often. Two reasons.

First is that I do not trust the manufacturers are acting in our best interest. They are proffit driven and will do anything to maximize that. Having long 10K oil change intervals helps them in that customers perceive long change intervals to mean less money on maintenance. It also helps with regulations. The 10K interval is designed to get the car out of warranty. Once it's out, it's beneficial to the manufacturer for that engine to fail. They know most people lease their cars and that 3+ year old car will now be in the used car market on its second or third owner. The sooner that car is dead, the better. The more maintenance that car needs the better. The original owner will be in their next new car oblivious to the long term issues of their prior car.

Second, I simply do not believe oil can protect an engine effectively beyond 5K in normal conditions and less in severe conditions. By the way, severe conditions include low mileage short trip cars, but many seem to think they can go further on oil changes because their car is low mileage. This belief is not just something I've fabricated. I have talked with plenty of top mechanics I trust who tell me what they believe based on the many years of building and rebuilding engines. Of course, there are plenty of counter opinions that say go 10K or even longer and at some point you have to make a choice on which to believe. I believe the people I trust who know much more about engines and lubrication than I do.

On to octane. This too, the manufacturer is focused on their own interests. They know that with the oil change interval there is little risk to the engine in the initial warranty period. With octane, it's more about fuel efficiency and meeting regulations. Also, better fuel efficiency gives the appearance of being less expensive to operate since you need less fuel. Nobody really considers the cost of that fuel since it fluctuates. They only focus on miles per gallon rather miles per dollar. But this is where the manufacturers own interests align with that of the long term owner. The manufacturer wants you to use high octane to improve efficiency while the owner should use it more to reduce premature wear on the engine and reduce the chances for costly repairs in the future. The manufacturer has the added benefit of if your engine does fail while in warranty and you have not been using the recommended fuel, they can deny your warranty claim. Win win for them.

 

Other than your opinion and youtube videos presented by people who financially benefit from more frequent service intervals than recommended by the manufacturers, do you have any hard evidence to support your theory that following MB recommendations of changing your oil every 10K is an "abuse". As more than 80% of E Class and S Class cars are leased, if you are correct the service bays at the dealership would be empty, yet they are not. So a lot of people who lease are servicing their cars including changing their oil and filter.

If so, please post. If not, then I am not one to think I know more than the engineers who made and designed my car and will continue to follow the engineers recommendations.


Again your are assuming the conclusion: engine failure at 120K without any proof whatsoever.

If you know anything about modern engines, then you know that they contain electronic pre-detonation, which prevents under modest driving, any harm from using regular than premium.

If you bother to read my posts you will see that if you race from a stop light, drive aggressively or at auto bahn speeds, speeds in excess of 100 mph or pull something behind you should use premium gas.

In Germany, the number one market for MB, people drive aggressively and need all the horsepower they can get from their engines. There is also a HP race and 0-100 km times between the Big Three: Audi, BMW and MB. To win that race each premium fuel is needed.



Nothing I or anyone else can add that will change your mind. Once you decide not to listen to the manufacturer, you have no guidelines and ipso facto, any guidelines you choose will be correct.





Again like not trusting the manufacturer you are now not trusting the makers of the oil. But there is a contradiction in your thinking:

Would not more frequent oil changes benefit financially both the oil makers and MB?

In the final anaysis, you are not really asking for opinions, but a forum to justify how you are servicing your auto. As I posted, doing service more frequently will not hurt, except in your pocket and possible wear on the groves and using premium fuel when regular is more than sufficient will not hurt, again only in your pocket book.

What would really be important is:

• Finding someone who has 150,000 miles on their engine and have an engine failure because of changing oil every 10K miles instead of every 5K miles
• Finding someone who drives modestly and has had an engine failure directly attributable to use regular instead of premium gas

Until that can be done, you and I have only opinions and you know what people say about opinions!

That is all for me on this topic.

 

If you actually took the time to actually read my post and think rather than assume, you would recognize that I have never said that 10K oil changes or using low octane fuel will cause damage. I say it "may" contribute to damage. I'm not trying to convince anyone. I'm only providing reasons behind why I do what I do which was a question you actually asked in another thread. The manual even states that the prescribed oil change interval is based on "normal" operation of the vehicle and that stressful operation will require maintenance to be carried out more often. In other words, the 10K interval you are so fond of using is a maximum if the vehicle is driven in perfect conditions. It goes on to say that regular city driving, short distance driving, mountainous terrain, poor road surfaces, idling for long periods, and even if air re-circulation mode is used frequently all amount to "arduous operating conditions" and should have the oil and other things changed more frequently. All you seem to see is the marketing hype of 10K oil intervals and fail to understand the nuance of the many factors that go into properly caring for your engine. You don't race, great! Do you drive through mountains, do short trips, sit in traffic, use the air re-circulation? If so, you are operating your car in extreme conditions and should decrease your oil change interval.


You say you trust the engineers but you have said time and time that you use 87 octane even though the same engineers say not to. In fact, they go so far as to say that if you must use 87 that you do so only to get you to the next station to fill with 91 or better. It literally states in the manual that using lower octane will lead to premature engine wear and impairment of the longevity and performance of the engine. Here it is in the manual.

 

After reading so many of his responses, I think that “JTK” stands for “Just To Kvetch” (to use a Jewish term)…

 

Turbos fry oil a lot faster. I have experience reviewing peoples used oil analysis. It really depends on your average drive cycle how much time you spend in traffic and idling because it's how much heat you put into it and how many times you heat up the oil per day. You can have far worse oil at 5k than at 10k for some people.

Oils a weird topic where people get way too attached to what they do and what they saw once whereas people in the service industry almost never believe what they see and rely on broad data from multiple sources. I recommend an interval of 7500 just because of the sheer amount of used oil I see. 10k is fine though it will protect for longer than that if it needs to in a lot of cases.

However theres only one way to know if your interval with your driving habits works for you, there isn't a set mileage. Used oil analysis. My referral numbers included in the link so itll support me/the forum.
https://www.amsoil.com/p/oil-analyze...it/?zo=7236674

 

Great point and that's exactly what I rely on. Being that the car is new, it's hard to say what the change interval is so I decided to do it more often. Here are the results of mine. I'll likely stay on a 5K change interval unless the oil analysis says to do it more often.

 

It is false economy to put 87 Octane, into a car that can readily use 91+ octane, due to the engine's compression ratio.

Yes, the car will not only make less power, but the lower power generation is present throughout the rev band.

So to be at a given speed (or to accelerate to a set speed level), you'd need a certain power number, and with lower octane fuel, you will need to be at a proportionately higher RPM, to be at that targeted power number. So you are in effect consuming more fuel (via being at a proportionately higher RPM), than you would have, by running higher octane.

 

5K change interval works for me, and that's what I follow. And I always put the highest octane rating available, into my cars, since both of my cars have high-compression engines that can readily use the higher octane. I stick to Shell gasoline whenever/wherever I can.

 

I just go by the book for fluids, and do 5K oil changes. I save my brain for the problems others haven't provided me the answers to.

 

Not in the real world: You can go into your touch screen and see how much HP you are actually using. At a constant 75MPH, less than 60 HP. My engine with premium is rated at 365 HP. With regular between 5% and 7% less, which is 335 HP, still 5 to 6 times what is necessary to maintain 75 mph! So no I am not running at high RPM: in fact at 75 mph the RPM is 1750!

Test have shown that switching from premium to regular will increase 0-60 from 4.9 seconds to 5.2 seconds. If I ever need to go from 0 -60, I can wait the extra .3 seconds!

I posted in another thread that coming home from Vermont, I switched from regular to premium. My range on fill up went from 704 miles to 724 miles an increase of 3%. However at Costco where I filled up premium was an extra $.60 per gallon or 30% more. At home the delta between regular and premium is closer to $1.00. To get 3% more mpg, it cost 30% more: that is not cost effective.

So your are back to whether there is any damage to your engine in the long run: So far I have yet to see anyone document any engine damage, while driving modestly, when using regular vs. premium. I average 8,000 miles per year and average 25 miles per gallon, that is approximately 320 gallons per year or $300 per year. In 20 years my car will have 150,000 miles on it and using regular I will have saved $6,000 which will be more than a 20 year MB with 150,000 miles on it will be worth!

So even if I have to junk my car at 150,000 miles I am ahead using regular and if the engine is still sound, which I think it will be, I have effectively doubled the value of my car.

That is the real world economics!

If my numbers are wrong, let me know.

 

If you have been filling up on regular all along, then you will need to go through at least 3 fill cycles with Premium, before you will see the improvement in mileage. That's the duration it takes for those little knock-sensors in the engine, to start relaxing, and realize that they no longer need to stay hyper-alert, to minimize the damage. And the engine in turn, advances the timing to take advantage of the higher octane.

It does not happen in a single fill-cycle.

 

The factory oil change interval is 10K miles for the E450 as well as the E53 Hybrid with the same M256 engine. After 7K+ miles the Mercedes app Trip Data indicates a 32% Electric Driving Ratio in my E53. Most of the miles I am putting on the car are at highway speeds at under 2000 rpms. I don't drive hard or in dusty conditions. I am comfortable with the recommended 10K mile oil change interval because the engine is at zero rpms nearly one third of the time.

 

Interesting. I thought like all electronics it happens in milliseconds- not nearly 2,000 miles - I get about 650/700 miles per tank full.

Please post your source for it taking 3 fill cycles, over 60 gallons, 2,000 miles.

Thanks!

 

I just change my oil once a year because I don’t put many miles on my cars. I’ve had my E450 for a little over six months and it now has 1800 miles on it. I’ll probably never put more than 4k a year on it.

I always put in high octane as an extra .60 a gallon doesn’t hurt my pocketbook a bit and I don’t like the thought of driving around with a detuned engine that’s constantly listening for pings..

 

When you put premium in a car that's been running on regular fuel all along, the knock sensors, which had retarded the timing severely, to account for the presence of regular fuel, starts learning immediately, that the car now has premium fuel. The "improvement" starts immediately, with the higher octane fuel.

The engine's ECU, then starts gradually (cautiously) raising the timing, yielding better power. Gradually, being the key-word.

And everytime you startup the car and drive, it will keep on raising the timing, as long as you consistently re-fill with premium. This raising of the timing all the way to the maximum, does not happen in milliseconds, since we are talking about the "teaching" of the engine ECU to now account for the presence of premium fuel, and that it is safe to raise the timing. That gradual raising of the timing to the point where the timing is raised to the full potential of that engine, is what takes multiple fill-cycles.

This is not purely electronics that get an instantaneous signal to switch to a specific setting, but a combination of electronics, and mechanicals that work together to eventually get to the engine's ideal timing, for that specific fuel type.

The reverse, is more problematic. If a car that's been running on premium fuel consistently, and the timing is opened up all the way by the ECU, now encounters regular fuel, the knock sensors will immediately encounter knock, and retard timing. Then encounters the next knock, and retards timing again. And so on, until it retards timing sufficiently down, to allow the engine to remain safe. Everytime knocking happens, there's a little bit of damage that occurs within the engine. That's why, in such a situation, it is not advisable to drive at high RPMs at all, to minimize problems for the engine.

In a similar way, when someone drives an Automatic equipped car, the car learns the shift patterns, over an extended period of time, and stores the learning internally. You now hand over the car to a race-car driver, and he/she drives it differently, the ECU will be confused as hell, and the new driver will feel there's something wrong with the transmission. The re-learning process again, takes time (several weeks at least).

When we hear about the "standstill adaptation" done by Mercedes to fix rough transmission shifting, it is nothing but updating the ECU, with shift patterns that Mercedes determined to be reasonable, for a majority of the population......and then the person drives the car, goes back to their old shift patterns, and in around a month or two, the rough shifting will return. This is the ECU re-learning this person's shift patterns. And so on.

Bottomline, the re-learning process of the ECU, whether in case of different gas, or whether in case of the transmission shift patterns, takes time.

 

Lexus says: We do not recommend using a lower octane fuel than what is recommended for your particular vehicle. Use of gasoline with an octane rating lower than what is recommended may result in engine knocking. Persistent knocking can lead to engine damage. But you may win the cheap bassterd award!

 

I for one, was schooled by your treatise. There is no need to think you can’t learn more on a subject you may already know quite a lot about. Thank you for your willingness to educate. Do not despair over those who refuse to acknowledge that you may know more than them.
In regards to this topic, does anyone know what Abraham Lincoln said?

 

Can you give me source of the above. Doesn't sound like what I understand an electronic pre-detonation actually does. My understanding is that the ignition, if and only if it senses pre-detonation retards the spark - it is not continually being retarded, but only on an "as needed basis".

I do know the transmission "learns" but never heard that the ignition learns.

Source of your information is appreciated.

Thanks..

 

Do a search for long oil change interval and you will find a ton of info with most saying 10K is way too long. This guy explains it pretty well.

 

But according to the above, he’s only saying this about oil because he does oil changes.

i’m not sure this thread is gonna keep the ignorance out of the other threads so much as point out who to never buy a used vehicle from.

I consider much of the basis of these discussions about people who like to be proactive versus reactive, regardless of their pocketbook or cost, because that has nothing to do with science.

 

Do manufacturers get carbon credits for delaying transmission service?

Rather than saying, "I have heard" similar to what our President says: "People are telling me or People say" the speaker before such pronouncements could have done a google search which I just did, (took 5 seconds) and he would have found the answer:

No:

see: https://www.google.com/search?q=do+c...hrome&ie=UTF-8


Interesting: I regularly check my oil level and change every 10K miles. I have never needed to add oil between oil changes. My car does not burn oil.

 

Where do you see it says "No", the AI response?