Jezza

How many of us here stick to the 10k mile oil change intervals on our V8 S-class'?

Doesn't it seem like a really damn short interval for an extremely lazy and detuned engine like these? (talking S430/500) My last BMW 330ci sport required servicing only every 15k miles or so as i only do motorway miles, yet this thing seems to count down from 10k without any regard to how the car has been used.

My S430 is around 2500miles overdue because of working all hours recently, and its oil still looks great to me, runs like a dream too. Dont these 10k services seem silly to anyone else?

newton22

I change my oil every 5000 miles religiously, regardless of what people tell me. Yes, I use Mobil 1 0W-40 Full Synthetic.

my06clk

Actually FSS is supposed to adjust to your driving habits.. so it may be more than 10K, or it may be less.. Here in the states the norm is 3K for every other car so 10K seems longer not sort...

BtW what do you mean by lazy detuned? Is there something wrong with your car?

whoover

In the US, starting with 2005 the service interval is 13,000 miles for that car. I don't think this reflects any change to the engine, just getting rid of FSS and a recognition that 229.5 oil with the fleece filter will go 15,000 miles.

AMGs have 10,000 mile service intervals, which I've always honored.

AsianML

The 10k miles FSS countdown isn't going to reflect 10k true miles driven. FSS will countdown the miles as necessary. I've figured most of my 10k FSS countdown miles to actually go for as long as 12-13k driven miles.

Jezza

I actually looked at my last oil change invoice last night and it was 17,000 miles ago, looks like i've done more miles than i thought and simply haven't noticed how the countdown has been working. So that's a 14,500 mile interval had it been on time which seems more sensible.

By lazy detuned i mean what i mean, its a 275bhp 4.3L engine! That's detuned by anyone's standards when we consider that my other half's car makes 300bhp from 3.4L, and the normal 3.0 BMW's make 265bhp from 3.0L. I realise that this engine is tuned for torque and longevity hence i'm not complaining, but as a result it should have wide intervals which i have just worked out it actually does.

sessayan

How the hell does it know to adjust the interval? Thats amazing that it can adjust based on driving conditions or is it checking the quality of the oil ?

whoover

FSS used an oil quality sensor in the crankcase, and also counted cold starts, monitored calendar time, engine run time, vehicle speed, engine speed, engine load, coolant temperature, oil temperature and oil level. It was quite accurate, but dropped because people prefer regular intervals rather than accurate but unpredictable ones. It was a classic case of a brilliant engineering solution to a problem that didn't exist.

Jezza

Do you know if this solution was dropped in the EU/UK models too? I ask as almost all european cars have variable intervals these days and i would be very surprised to see that Mercdes didn't.

I am very glad it exists on mine for sure, it is absolutely unnecessary to change oil in an engine like this every 10k as a non variable counter would suggest, and i would resent doing so.

whoover

I'm pretty sure they dropped it worldwide in 2005.

srknutson

I would never go over the 12 month 10k. I'm very OCD and go every 5k or 12 months. Whichever comes first.

Jezza

Obviously it depends on the type of usage the car is getting, you sound as though you don't use the car much and therefore i would assume do mainly short journeys. I am assuming pretty much 100% motorway usage I do over that 5k every single month, servicing that often would get rather expensive!

srknutson

Agreed, petrol must cost a quid or two.

manano

i live out in Dubai so we have to deal with kms i/o miles.. Just had service B done on my S350 2005 W221. I ran the car for just over 15k kms and then took it over to the dealer to get the job done. I thought i was going to be in for a mouthful since the service advisor is a friend of mine since i'm usually careful about over running my service interval.

Anyway long and short of it, the guy told me that with the recent advances in the type of oils used by MB, one does not have to be super strict with the service interval.

My driving is mostly freeway driving and i go through 10k kms in a matter of a couple of months (sometimes less). I sure was glad to hear that !

Also i've heard that BMW have increased their service interval from 10k kms to 25k kms !! Now that's a HUGE jump IMO..

I'm wondering if these advances in service intervas have to do exclusivly with the oils or even engine design ?

rccmerc

No, it has to do with demonstrating lower cost of ownership. Both MB and BMW throw in a free service period with their warranty. When this began the recommended service intervals changed significantly. Considering most of these vehicles are leased in the USA... When it is on the manufacturers dime less is more! Better for the vehicle, Hmmm. Reminds me of lifetime fluids - What is a lifetime? Well, when your transmission blows up - that is the liftetime of the fluid

AsianML

MB no longer has the free service period with the warranty anymore since MY05. That's also when they changed to 13k fixed intervals.

westcoast5

so what if you ony drive your car 7000 to 8000 miles a year? do you change it once a year?

rccmerc

Thanks for clarification. However, in the DC Metro Area MB Dealers will offer/entice with a limited free maintainence offer. Anyway all the best.

Skylaw

Yes, according to my FSS and service manual.

Musikmann

I have heard that's a rule of thumb for conventional oil. I don't think it applies to fully synthetic. With my car I follow the FSS intervals.

westcoast5

so since I use full synthetic when it says change it then do it? even though it might go well beyond a year?

da boss

i do it every 5k miles. All the time.

newton22

I wouldn't let oil sit. If you ask me, I would change my oil AT LEAST twice a year. Usually for me it's 2-3 times annually.

Look, MB/FSS recommends 10k+ oil changes. These cars have engines just like any other car. They have mechanical components, just like any other car. So just like any other car, the oil life can only last so long. I mean, if you really wanted to, you can drive any healthy car out there to 15k-20k miles without changing the oil, and nothing will probably happen. However, why would you put the engine through that kind of stress?

If you TRULY wanted an accurate oil change interval, you can send your used oil samples to labs for diagnosis as every car is different and oil life is dependent on driving habits. Otherwise, I prefer to have the peace of mind that my engine is properly lubricated at all times. I'd rather change my oil every 5000 miles, even if it's wasting oil, than be oblivious and have the components of my engine experience increased stress and friction.

Skylaw

If you do follow the FSS, and you have not approached the mileage limit programmed into it, the FSS will switch to a limit based on time. The readout will go from "Service in xxx miles" to "Service in xx days." And it certainly does so for synthetic oils, including those meeting MB specifications.

With respect to changing oils based on time, it is a matter of exhaust gasses coming into contact with the oil during normal engine operation, creating acids in the oil. By contrast, in changing oil based on mileage, it is a factor of breakdown of the molecular chains that provide the oil's lubricating capability. There are other factors as well, but those are the principal ones.

Jezza

I dont know why you guys seem to have that culture over there, over here it is normal for petrol engines to be serviced at between 15-20k miles. Everything from Vauxhall (GM), BMW, Ford, Mercedes, Peugeot/Citroen etc etc has those kind of intervals.

Climate conditions maybe?