[JJS]

Yesterday, my F31 was serviced and that included an oil change at 30,000km, which is the factory service interval. For my peace of mind, I had the original oil changed at my cost at 15,000km. So all is good.

But when I checked the service information, it shows the next oil change is due in 35,000km or 24 months. The service manager explained that the car's CBS determines when it needs to be changed and obviously my car has been gently driven in its first 30,000km. I smell something fishy.

Can anyone confirm whether the latest 35,000km interval is a value entered by the technician or whether the car determines (with factory programming) the interval when the tech resets the oil status?

[x5mad]

Originally Posted by JJS

Yesterday, my F31 was serviced and that included an oil change at 30,000km, which is the factory service interval. For my peace of mind, I had the original oil changed at my cost at 15,000km. So all is good.

But when I checked the service information, it shows the next oil change is due in 35,000km or 24 months. The service manager explained that the car's CBS determines when it needs to be changed and obviously my car has been gently driven in its first 30,000km. I smell something fishy.

Can anyone confirm whether the latest 35,000km interval is a value entered by the technician or whether the car determines (with factory programming) the interval when the tech resets the oil status?

There are plenty of threads on servicing intervals.

However, 35k is far too long. The next interval is a combination of VO and what the service tech sets.

For example my vehicle order is 30k/24 months. I had it serviced at 13k (coded a different VO). When I put the car in for service I changed my VO back to original and was expecting the next service to be in 30k, however the car was returned to me with next service showing as 13k. So I'm guessing the tech inputted 13k based on my first service being at that mileage.

[adhrp]

I don't know about Aus or NZ, but my first service was done after 12k miles, second after 16k miles and third is showing due after 13k miles. So it varies depending on driving conditions and apparently there's a sensor that measures the dielectric properties of the oil to determine if it's time to change it (there's a link to a BMW document about this somewhere; you can search for it). Also, many of us on the forums have reported the OCI changing rapidly (usually dropping) after a few thousand miles post-service.

Either way, 35k km is very long. I think immediately after an oil change, the system works similar to the fuel tank range calculator which bases it off how much you got on the previous tank. Then, it eventually retunes to your driving style and conditions to change its forecast.

[chiefneil]

Originally Posted by adhrp

I don't know about Aus or NZ

Euros have much longer oil change intervals, probably because their gas is better.

[E90Fleet]

Its normal.
The car will adjust this figure in the next few thousand kilometers as it determines how the engine is being used.

They rarely stay at 35,000km

[E90Fleet]

Originally Posted by x5mad

There are plenty of threads on servicing intervals.

However, 35k is far too long. The next interval is a combination of VO and what the service tech sets.

For example my vehicle order is 30k/24 months. I had it serviced at 13k (coded a different VO). When I put the car in for service I changed my VO back to original and was expecting the next service to be in 30k, however the car was returned to me with next service showing as 13k. So I'm guessing the tech inputted 13k based on my first service being at that mileage.

Techs can only reset the CBS, they cannot input mileage between services. That is determined by the software loaded on the car.

[JJS]

Originally Posted by E90Fleet

Techs can only reset the CBS, they cannot input mileage between services. That is determined by the software loaded on the car.

That's interesting, thanks. So why would the reset CBS say the next oil change is 35,000km or 24 months away given that my car was shipped with a 30K/24m OCI?

Incidentally, the next service is due in 15,000km or 12 months, which is what I expected. But not the OCI. Let's see if this changes with use.

[x5mad]

Originally Posted by chiefneil

Euros have much longer oil change intervals, probably because their gas is better.

I should have been clearer but my service intervals are also in km.

Australian cars are coded from factory with 30k km / 24 months.

We have plenty availability of 98 RON petrol.

[chiefneil]

Originally Posted by x5mad

I should have been clearer but my service intervals are also in km.

Australian cars are coded from factory with 30k km / 24 months.

We have plenty availability of 98 RON petrol.

I think part of what drives lower-mileage oil changes in the US is the higher sulfur content in our gas. Old timers will remember the nikasil and alusil fiascos from the late 90's, with US gas destroying engines in the 5-series.

http://wardsauto.com/ar/mercedes_dirty_fuel_110315

[Fille]

Originally Posted by chiefneil

Euros have much longer oil change intervals, probably because their gas is better.

Absoloutely NOT because of better gas, which I doubt is better...

The truth is that the service intervals are so long because they are free for three years, this is to appeal mostly to company car drivers and fleet companies.
And because the service is free, the intervals can't be as short as they should. They really stretch the limit of the synthethic oils.

[x5mad]

Originally Posted by E90Fleet

Techs can only reset the CBS, they cannot input mileage between services. That is determined by the software loaded on the car.

Australian cars are coded with 30k km oil change intervals. Which I'm guessing you are referring to as the manufacturer software.

I changed the coding so it would come up quicker. I got my first oil change done at 13k km. Left unchanged, most cars in Australia are getting oil changes at 30k km give or take and when reset will have OCI at 30k km again.

Before I dropped the car off, I changed everything back to original. Therefore the next OCI should have been 30k km. But it was reset at 13k km.

I'm curious as to what software comes into play here. Ie reading on the forums you would think a complex interaction of specific country code VO and a multitude of sensors.

But in my case, for all intents and purposes the car came in its original state. The car was not beat on, fuel quality always top tier 98 RON, always warmed up before opening her up, rarely redlined, rarely above 110km/h etc etc.

So, the only "anomaly" is that my oil was changed at 13k km. Every other sensor and software is saying next change should be standard ie 30k km.

Therefore, is next OCI based on just when your car came in or did the dealer have something to do with the interval? I know I can manipulate the next oil change easily why not the dealer? It would mean more money for them over time.

[chiefneil]

Originally Posted by Fille

Absoloutely NOT because of better gas, which I doubt is better...

"Mercedes Says Dirty Fuel Problematic in U.S."

"But the sulfur limits for gasoline are much higher – 80 ppm at the refinery gate and 95 ppm downstream, according to the U.S. Environmental Protection Agency."

"Meanwhile, the European Union already has reduced sulfur content in gasoline “to near zero,” Heil says."

http://wardsauto.com/ar/mercedes_dirty_fuel_110315

[adhrp]

Originally Posted by x5mad

I should have been clearer but my service intervals are also in km.

Australian cars are coded from factory with 30k km / 24 months.

I calculated the equivalent miles when I wrote my post and it still is too long. I am not one to do intermediate changes when the OCI is 10-12k miles, but for a nearly 22k mile interval I'd most definitely do one on my own dime at ~10-11k miles.

[Tomahawk]

Also, in the States, the interval is mileage OR 1x/year. A lot of folks don't know this. If a car is a 18months old w/8k miles but never had an oil change, it cannot be certified when trades/turned in.

[dreamspeed]

Originally Posted by chiefneil

I think part of what drives lower-mileage oil changes in the US is the higher sulfur content in our gas. Old timers will remember the nikasil and alusil fiascos from the late 90's, with US gas destroying engines in the 5-series.

http://wardsauto.com/ar/mercedes_dirty_fuel_110315

Old timers and late 90s? Lol. What do you consider old? Like 30? lol