Custom oil change intervals: harmful?

Hello,

Currently, I only drive my BUK (1.9L PD TDI) about 7,000 km per year, mostly two trips of 20 km each daily.
Seat specifies the use of 507.00 Möl, which is suitable for WIV standards, but the car doesn't recognize or accept it.
Therefore, after the fixed intervals (annually or 15,000 km), I would change the oil after approximately half of the specified mileage. However, the same oil can often be used for a much longer period in closely related engines with variable valve timing (VVT), depending on the driving conditions.
Therefore, I performed the oil change yesterday after approximately 10,000 km and a year and a half since the last change. The basis was my gut feeling: "A 50% longer stay time in the engine, with 2/3 of the regular kilometer performance, should ideally/hopefully still be manageable."
Could that be right, or am I definitely wrong about it? If that's the case, what am I doing to my engine?

I think that's good so far. However, with such low mileage, I would use a 5W-40 oil that meets the 505.01 specification and change it every 12 months.

I never really liked LL's work in the old PD videos, various reasons. Some sources claim that it might be caused by worn camshafts.

So, I generally try to stay away from large language models.
The quality has certainly improved, and there's no question about that. However, I would still change the oil annually or every 15,000 km.
I doubt that driving it for another six months will damage your engine.

I have an old Fiesta undergoing maintenance. It has already had two clutches replaced, and in the 20 years it has been owned, the owner has only done about 5 oil changes, using oil that costs less than 10 euros for 5 liters.

A maintenance interval has to cover a wide range of usage scenarios. It needs to account for everything from someone who drives 10 kilometers every day to someone who drives 15,000 kilometers continuously at full load (considering the extremes). A manufacturer always has to plan for the worst-case scenario. I believe that with a bit of common sense, everyone can find their own niche.

I extended the fixed maintenance interval for my Golf because it has consistently been driven for 107 km at a time over the past four years. Now, it's nearing 380,000 km (and the next owner will likely drive it a lot too), and it's performing similarly. So far, no problems.

Quote:

I think that's good enough for now. However, with such low mileage, I would use a 5W-40 oil that meets the 505.01 specification and change it every 12 months.

. Especially if there is no DPF (Diesel Particulate Filter).

Hi,

I would also use a good quality oil with a wider range of specifications than LL 507.00 and change it annually.
My own long-term test with M**** 10W-40 oil, changed annually (22,000-26,000 km per year), has been running since 190,000 km, and is currently at 234,000 km.

I am unable to translate "haithamina" because it does not appear to be a word or phrase in the German language. It may be a misspelling, a proper noun, or a term from a specialized field. If you can provide more context or clarify the intended meaning, I would be happy to assist you with the translation.

TDI-GTI-4-Motion wrote:

I think that's good enough for now. However, with such low mileage, I would use a 5W-40 oil that meets the 505.01 specification and change it every 12 months. I never really liked LL's work in the old PD videos, various reasons. Sources also claim that it might be due to worn camshafts.

What would you choose with an annual mileage of around 30,000 km? ASV and BLT receive.
Currently, both are using 5W-30 LL3 oil and are reporting oil change intervals between 25,000 km and 30,000 km.

Best regards,
Micha

ulf wrote:

... or am I definitely wrong about that?...

No. Okay.


But let me ask a counter-question:
Why should you consider switching after just 12 months with a 50700 implant, when a "true" WIV patient typically only needs a replacement after 24 months?

The oil change is simply necessary because oil can degrade even when the car is not being driven. However, this degradation should be the same for both cars with and without a water injection system, as long as the same type of oil is used. So, theoretically, you could even let the oil steep for up to 24 months, that's what it's designed for.
Since this procedure is not approved, it's difficult to make any statements about it.
But, in my opinion, your compromise involves very little risk.

Bertil wrote:

Why should you switch after just 12 months with a 50700, when a "real" WIV patient only needs to switch after 24 months? The oil change is simply necessary because oil can degrade even when the car is not being driven. However, this degradation should be the same for both cars with and without a water injection system, as long as the same type of oil is used. So, theoretically, you could use WIV oil to steep for up to 24 months; that's what it's designed for.

Thank you for the tip.

Generally, one must consider how long the oil should remain in the engine.
Simply referring it to the oil standard 507.00 is actually nonsense.
507.00 essentially means low SAPs and a 5W-30 viscosity with a HTHS (High-Temperature High-Shear) rating of 3.5.

It becomes problematic for diesel engines when using low-SAPS oil (without low-SAPS oil, a lifespan of 50,000 km is possible).

With diesel fuel, there is a possibility that the oil can thicken due to the presence of sulfur, which can alter its viscosity.
Thicker oil is more harmful to the engine than thinner oil, and this is within the acceptable range.
Is VW's 507.00 specification in 5W-30 a longlife oil?
Up to 2 years.
Up to 30,000 km.
"bis" does not always mean "until" or "for" a period of two years.
"Up to 30,000" does not necessarily mean that 30,000 is always possible.

Since the amount of fuel that enters the engine oil is high in the winter, and biodiesel remains in the engine oil, it would probably always be advisable to change the engine oil in the spring.

VW now requires the oil specification to be re-applied every two years.
There were probably too many "black sheep" among the 507.00 engine oil products.

In your case, I would always recommend using Mid Saps oil with the 505.01 specification in a 5w-40 viscosity, and changing it every 12 months.
Today's 5W-40 oils are, in a way, more like 5W-36 oils, and 5W-30 oils are more like 5W-32 oils.
You're more likely to find 5w-40 in oils with lower SAPs (Sulphated Ash, Phosphorus, and Sulfur).

My assumption is that the commonly used xxW-30 oils today primarily serve the purpose of allowing them to pass through a heavily clogged oil filter, even with a lower base viscosity and longer change intervals, without opening the bypass valve.
On the other hand, the power consumption on the test bench should be kept as low as possible, and that is naturally easier with a low-viscosity oil.

Am I correct with these assumptions?

vwSchrauber wrote:

My assumption: the xxW-30 oils commonly used today primarily serve the purpose that, with their lower base viscosity and long change intervals, they can still pass through a heavily soiled oil filter without opening the bypass valve. On the other hand, the power consumption on the test bench should be kept as low as possible, and that is naturally easier with a low-viscosity oil. Am I correct with these assumptions?

"I believe the key factor is the low fuel consumption of the engine when using 0W or 5W oil. The -30 or -40 values simply indicate the properties at high temperatures (in simplified terms). For example, a 0W-40 oil, like the Mobil1 I mentioned earlier (which doesn't have VW approval!), is significantly more expensive for VW vehicles compared to a 5W-30 oil. And since the low-temperature viscosity should be as low as possible, as mentioned above, you ultimately end up with a 50700 (5W-30) oil." The early PD oil 505.01 was a 5W-40 and was often fully synthetic, which, in my opinion, is better.
I am unable to translate "haithamina" because it does not appear to be a word or phrase in the German language. It may be a misspelling, a proper noun, or a term from a specialized field. If you can provide more context or clarify the intended meaning, I would be happy to assist you with the translation.

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The low fuel consumption of the engine when using 0W or 5W oil is, in my opinion, the most important factor. -30 or -40 "only" indicates the properties at high temperatures.

I understood that a 5W-30 oil is equivalent to an SAE30 oil at operating temperature, and a 5W-40 oil is equivalent to an SAE40 oil at operating temperature. Am I wrong about that?

That would explain why, for a long time, oils like SAE 15W-40 or single-grade oils were common in the commercial vehicle, stationary engine, and agricultural sectors.
Unlike passenger cars, trucks, tractors, and generators experience significantly less cold start operation compared to their total operating time. Simply having a lower displacement is not a valid argument here, especially since these engines achieve their rated power at significantly lower RPMs and also operate at full load much more frequently.

vwSchrauber wrote:

I understood that a 5W-30 oil is equivalent to an SAE30 oil at operating temperature, and a 5W-40 oil is equivalent to an SAE40 oil at operating temperature. Am I wrong about that?

No, you're right about that. Similarly, this applies to single-grade oils used in stationary engines, or those that "always" run and have operating temperatures that don't vary much.

And: Fuel savings (on paper, i.e., in the test cycle) are achieved better with 0W oil than with 5W oil. However, in my opinion, a 0W oil is always a fully synthetic oil, just like one with a wide viscosity range, such as a 5W-40 or even a 0W-40 oil. Therefore, cost pressure is certainly the best explanation for 50700 oils as a good compromise: semi-synthetic, with low viscosity for frequent cold starts, -30°C is sufficient for diesel engines (in modern engines in general), and oil temperatures above 120°C are very rare or nonexistent for most drivers.
The long-term stability and dirt/soot absorption capacity of WIV oils are determined by the manufacturer-specific additives, not by the viscosity grade range such as 5W-30 or 0W-40.

I am unable to translate "haithamina" because it does not appear to be a word or phrase in the German language. It may be a misspelling, a proper noun, or a term from a specialized field. If you can provide more context or clarify the intended meaning, I would be happy to assist you with the translation.

haithamina wrote:

And: Fuel savings (on paper, i.e., in the test cycle) are achieved better with 0W than with 5W.

Please provide the text you would like me to translate from German to English.
Fuel savings can only be achieved with a 30-grade oil.
40-weight oil always loses viscosity, whether it's 0w-40 or 5w-40.
Nowadays, a 0W-40 oil can be used down to temperatures as low as -60°C, while a 5W-35 oil is only suitable down to approximately -42°C.

You need to develop a better sense of feeling for it.
Water exhibits the best temperature behavior; regardless of the temperature, as long as it remains liquid, it maintains a constant viscosity value of 1 ± 0.5.
5W-30 oil often has a viscosity value of 12 at 100°C.
at 40°C, the value is 65-70.
5W-40 oil often has a viscosity index (VI) of 13-14 at 100°C.
At 40° (Celsius), the value is 70-80.

Conclusion: Considering the average engine oil temperature throughout the entire lifespan of a car, using a 5w-40 or 0w-40 oil results in a significantly thicker oil, especially during the first 10 minutes, which leads to increased fuel consumption.

So, there's no advantage to using this oil compared to a 0w-35 oil, except that the 0w oil can handle temperatures down to -60°C. Even a 0W oil remains viscous in extreme cold and never becomes thinner until the oil actually "freezes."

Am I understanding correctly that you're saying that even if two oils have different pour points, their viscosity might not be different at a specific temperature?
hg
Herbert.

PS:

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Water has the best temperature behavior; regardless of the temperature, as long as water is liquid, it always has the same viscosity value of 1 +/- 0.5

.
No - 1 mPas at 20°C, which decreases significantly with increasing temperature.