Can oil last 20,000 miles?

[Alex225]

Personally I have the oil changed in my daily car every 12 months, I would continue to do so whether the recommendation was 20k because I consider oil servicing to be part of the ownership of the car. Peace of mind also plays a part.

That said, I do believe oils can last this long. Even when I bought my second car, an 8 month old Clio 1.2 back in 2001 the service intervals were 18k/2 years. Considering that was nearly 20 years ago and I'm sure technology has moved on even more since then.

Considering there are people out there who don't even know about their cars servicing and probably miss even a 2 year interval we're just a cautious lot, which is no bad thing!

 

[markjay]

Stretching the oil change intervals is fine if you have the means to carry-out regular lab-testing of samples of the engine oil in the car.

But just because a test showed that under certain conditions the oil still tested fine after 20,000 miles, it does not mean that the oil will be fine for the same distance under your particular circumstances.

It will depend on a very large number of variables, including ambient temperature and humidity, engine operating temperatures (long/short journeys), dilution of oil by fuel, water content through moisture absorption, oxidation over time, number of cold starts, the gears that the car is driven in, driving pattern and rev range, the number of hours that the engine was in operation (not just mileage), etc etc.

The manufacturers' maintenance schedules err on the side of caution, and in fact they say that in frequent stop-start driving conditions (and others) the maintenace intervals should be halved - but few people take note of that....

So while in essence it is true that if you could regularly test the oil quality, then there would be no harm in simply using the same engine oil until the lab tests show that its performance have deteriorated/degraded below a certain level. But this approach may be practical for fleet operators, not for private owners.

 

[glojo]

With the very greatest of respect to everyone we definitely sound like those who thought we would all die if car speeds exceeded 30mph!!

This is an extract from the Mercedes Actros site.. The largest Mercedes truck on our highways and bye ways

Depending on application, the Telligent® maintenance system allows service intervals of up to 120,000 km and optional oil-change intervals of up to 150,000 km . This is because it is based on the actual wear and tear of the Actros – enabling the potential of all the operating fluids to be utilised.

I am guessing the cost of those huge Actros engines far, far exceed the costs of the nicest cars some of us own and if these engines can run the mileage they acrue, then we have NO worries regarding our oil change. I know for me, I to am guilty of being old fashioned and still insist on my Sprinter being serviced every 12 months but I used to have a battle with the service manager regarding changing the oil.... he thought I was daft and if I am being totally honest, I now listen to that man's expertise. The van is serviced and the MOT carried out but the oil changes, I leave to his discretion.

I understand folks saying how it is a good investment to do this at every 3000, 5000 or 12000 miles and probably on older engines it might be, but when we have diesel engines easily and confidently doing 90,000 miles between oil changes at no risk and no harm then I feel silly saying I want my Sprinter oil change carried out every 12 months and yes this is the 2.2ltr diesel that is son common throughout the Mercedes range of cars.

 

[whitenemesis]

Stretching the oil change intervals is fine if you have the means to carry-out regular lab-testing of samples of the engine oil in the car.

Wasn't this exactly what ASSYST did? It constantly measured the conductivity of the oil and along with mileage, the number of IGN cycles and temperature determined the variable service intervals?

 

[ChipChop]

If you have stop/ start activated must be a major factor in how long your engine oil stays up to spec i would have thought. All those extra ignition cycles and rapid acceleration (from traffic lights etc.) must play havoc with an engine.

 

[rf065]

Wasn't this exactly what ASSYST did? It constantly measured the conductivity of the oil and along with mileage, the number of IGN cycles and temperature determined the variable service intervals?

Exactly, as in my previous post, 18,000 miles & two years was the norm for mine.

 

[alabbasi]

I dont see the point of servicing any car earlier than the recommended intervals. The manufacturer recommended intervals will likely have a large margin added as well.

Manufacturer service intervals are designed to be cost effective for their maintenance plans or attractive to fleet buyers in places where they don't offer servicing as part of a new car sale.

Over the long term they couldn't give a crap once the warranty expires. They're off the hook after 4 years and 50,000 miles.

 

[andy27168]

Hi
I normally buy the oil below, which is what I bought from VW Commercial and what Audi tried to sell me, I got a thing for using genuine oil, having three cars two MBs 207 convertible Diesel, 219 AMG and a Audi Cabriolet V6 Diesel, means there are three lots of oil containers.

VW Golf 6 Plus 10 Genuine Quantum 5w30 Long Life Engine Motor Oil 5l for sale online | eBay

Find many great new & used options and get the best deals for VW Golf 6 Plus 10 Genuine Quantum 5w30 Long Life Engine Motor Oil 5l at the best online prices at eBay! Free delivery for many products!

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[Will]

Poor maintenance does lead to issues, e.g. 'black death' on Diesel engines etc. The point however is that cars change hands usually every 2-3 years, so it's typically the next owner (or the one after that) who pay the price of the neglect.

I think Black Death relates to leaking injectors on Diesel engines nowadays. Changing the oil every 5k miles isn’t going to do anything to prevent that

 

[markjay]

Wasn't this exactly what ASSYST did? It constantly measured the conductivity of the oil and along with mileage, the number of IGN cycles and temperature determined the variable service intervals?

There were two types of flexible ASSYST.

The basic type simply calculated the service interval based on logic, I.e. monitoring various parameters such as cold starts and length of journey etc. But it was an 'educated guess' because the system had no way of knowing what the oil condition actually was.

Some cars (I believe only Diesels?) were also equipped with oil quality sensor and oil quantity sensor. The oil quality sensor simply measured conductivity (as you pointed-out), which reflected the water content in the oil. The oil quantity sensor was used to increase the oil change interval in the event that fresh oil was added between oil changes (and mixed with the old oil).

In either case, if the mileage was low, the system reverted to time-based intervals. This is because of the oil oxidation over time, and also because the full service schedule includes various other checks that shouldn't be delayed for too long.

But it's important to note that no ASSYST system was actually able to analyse the oil performance in real time - instead, it was, as said, based on a series of educated guesses.

With regards the Actros engines... I am guessing that (a) the mileage information relates to engine oil change intervals only, but not to other scheduled servicing, so the truck may still need to be serviced between oil changes in respect of other service items falling due, which isn't practical for a private owner who uses a dealer, (b) the mileage is in respect of driving under optimal conditions i.e. long-haul fixed-dpeed motorway causing, and (c) given the cost and the technology of the Actros engine, it is possible that it incorporates advanced sensors that can actually analyse oil performance in real time. So in summery I wouldn't automatically assume that what MB say about their Actros engines is applicable to privately-owned cars.

 

[190]

I think the evidence is plain to see. Even though it was safe and suitable for some users, manufacturers have backed away from a 2 year/20,000 mile service interval. If Mercedes and others think it was a step too far then you can be sure it was.

There was a more sensible alternative to a return to 12 month service intervals. It could have been left at 2 years with an intermediate oil change. If it was just an oil change and absolutely nothing else then the cost could have been capped very low with no excuse for it to have been above £100 and if anyone other than MB were doing it a fair bit less than £100. A properly organised and streamlined service centre could change oil in 15 mins tops with no faffing about cleaning the car and providing free coffee. In fact it could have been organised on a drive through basis, think what F1 guys can do in 2 seconds. Depending on the miles driven there wouldn't necessarily have been a need to change the filter which could have reduced the time to 10 mins. That may draw some comments but a slightly dirty filter is more efficient than a new one and if the filters were lasting 20,000 miles anyway they would be good enough for 2 oil changes of 10,000 a piece.

 

[markjay]

I think Black Death relates to leaking injectors on Diesel engines nowadays. Changing the oil every 5k miles isn’t going to do anything to prevent that

True, but there's more than one reason for it, see for example:

Heard of the 'Black Death' in engines?

The Black Death 'health' pandemic resulted in the deaths of an estimated 75 to 200 million people in the years 1346–53! The ‘Black Death’ we are referring

svsautocare.com.au

 

[ToeKnee]

I change the oil on my daily at least three times a year, sometimes more often.......

 

[markjay]

I think the evidence is plain to see. Even though it was safe and suitable for some users, manufacturers have backed away from a 2 year/20,000 mile service interval. If Mercedes and others think it was a step too far then you can be sure it was.

There was a more sensible alternative to a return to 12 month service intervals. It could have been left at 2 years with an intermediate oil change. If it was just an oil change and absolutely nothing else then the cost could have been capped very low with no excuse for it to have been above £100 and if anyone other than MB were doing it a fair bit less than £100. A properly organised and streamlined service centre could change oil in 15 mins tops with no faffing about cleaning the car and providing free coffee. In fact it could have been organised on a drive through basis, think what F1 guys can do in 2 seconds. Depending on the miles driven there wouldn't necessarily have been a need to change the filter which could have reduced the time to 10 mins. That may draw some comments but a slightly dirty filter is more efficient than a new one and if the filters were lasting 20,000 miles anyway they would be good enough for 2 oil changes of 10,000 a piece.

Firstly, many dealers do offer an 'interim service', aka 'oil service', which they will tell you is 'not to the manufacturer's schedule'. It costs less than a full Service A or Service B (though being MB dealers it isn't 'cheap' as such...).

Then, in the olden days we used to change the (mineral) engine oil every 3,000 miles, and the engine oil plus oil filter every 6,000 miles. I am guessing that with the extended service intervals for moderm semy-synth and full-synth oils, reusing the oil filter is false economy, especially given the low cost.

 

[SlimJim]

I wonder what the Oil Companies would say about the recommendation to change their product after 3-5k miles and a year. Would they be happy about their products being so “flaky” that they are deemed useless after so little use ? (Increased sales apart).
I have never read any advertising bumff about the fragility of their Engine Oils.

 

[Will]

True, but there's more than one reason for it, see for example:

Heard of the 'Black Death' in engines?

The Black Death 'health' pandemic resulted in the deaths of an estimated 75 to 200 million people in the years 1346–53! The ‘Black Death’ we are referring

svsautocare.com.au

It’s the injector seals that leak (and hence diesel fuel sprays out of the bores past the injectors) which builds up and gets cooked. It’s not engine oil and changing the oil won’t help - you need to re-seat the injectors and fit new seals

Changing the engine oil more often won’t help this at all

 

[rf065]

I think the evidence is plain to see. Even though it was safe and suitable for some users, manufacturers have backed away from a 2 year/20,000 mile service interval. If Mercedes and others think it was a step too far then you can be sure it was.

It was a step too far only in as much as moving to a yearly service limit & 15,500 miles, would mean many more cars in the workshop, more money for them.
Put the exact same engine as many cars use in a Sprinter and the service intervals are over 30,000 miles.

 

[Will]

There were two types of flexible ASSYST.

The basic type simply calculated the service interval based on logic, I.e. monitoring various parameters such as cold starts and length of journey etc. But it was an 'educated guess' because the system had no way of knowing what the oil condition actually was.

Some cars (I believe only Diesels?) were also equipped with oil quality sensor and oil quantity sensor. The oil quality sensor simply measured conductivity (as you pointed-out), which reflected the water content in the oil. The oil quantity sensor was used to increase the oil change interval in the event that fresh oil was added between oil changes (and mixed with the old oil).

In either case, if the mileage was low, the system reverted to time-based intervals. This is because of the oil oxidation over time, and also because the full service schedule includes various other checks that shouldn't be delayed for too long.

But it's important to note that no ASSYST system was actually able to analyse the oil performance in real time - instead, it was, as said, based on a series of educated guesses.

With regards the Actros engines... I am guessing that (a) the mileage information relates to engine oil change intervals only, but not to other scheduled servicing, so the truck may still need to be serviced between oil changes in respect of other service items falling due, which isn't practical for a private owner who uses a dealer, (b) the mileage is in respect of driving under optimal conditions i.e. long-haul fixed-dpeed motorway causing, and (c) given the cost and the technology of the Actros engine, it is possible that it incorporates advanced sensors that can actually analyse oil performance in real time. So in summery I wouldn't automatically assume that what MB say about their Actros engines is applicable to privately-owned cars.

Mercedes-Benz have definitely fitted oil quality sensors to plenty of petrol cars over the last twenty years or so. Can’t say all but I’d be surprised if most didn’t use them these days.

I don’t think they increase the length of the service intervals - post service the indicator is reset. On some of the cars with 2-year intervals you’d get a mileage or time based interval, which would obviously be reduced if you reached the mileage threshold before time, or I would have thought if the oil quality sensor detected significant deterioration in quality.

Again though, many of these cars will have been scrapped now at twenty years old, the vast majority with perfectly good engines (eg M112,113 from the early 00s) and most will have 100-200k miles and only serviced when required

The remaining ones are still running perfectly well and very few will have had oil changed 40 times in 200k miles

 

[Tonygw]

Is there any harm in changing your oil more regularly than the official recommendation? I dont think so. And its not expensive to do

If nothing else it aids to keep the oil ways clean and on modern engines, thats important, its not the engine that fails but things like the turbo can suffer early failure??

each to their own..

 

[190]

Is there any harm in changing your oil more regularly than the official recommendation? I dont think so.

Actually it's possible there is. A report showed that the build up of anti-wear coating on engine surfaces was removed by the new oil so that wear rates increased for a period until the coating was built up again. I'm a fan of regular oil changes and do mine every 5000 miles which for me is 12 months. I would run it a little longer than that if it wasn't for the expectation of an annual service. For higher annual miles I would not consider doing it more often than 6000 miles.

Severe use such as mainly short trips would override any other consideration and justify more frequent oil changes.