General consensus on long interval oil changes.

[Mave]

B'stard Child said:

Is that F or C, I'd not be happy with 130 deg c as a max let alone min

That's C, at cooler inlet, on a well designed dry sump system where you don't allow the oil to sit and cook.

[Megaflow]

With modern oil 125 degs C as a continuous temperature is fine, with peaks up to 135 degs for limited periods.

170 degrees would led to serious issues. Although fair play for understanding the temperatures are higher than water, most people see oil temperatures of 100 and panic, fit oil coolers, etc. or worse still fit and oil cooler just because they think the need one with no consideration to temperature at all!

[Mave]

Megaflow said:

With modern oil 125 degs C as a continuous temperature is fine, with peaks up to 135 degs for limited periods.

170 degrees would led to serious issues. Although fair play for understanding the temperatures are higher than water, most people see oil temperatures of 100 and panic, fit oil coolers, etc. or worse still fit and oil cooler just because they think the need one with no consideration to temperature at all!

Depends on the oil, and the detailed features of the engine design. I've run industrial engines with oil going between 130 and 180C for a few thousand hours with minor levels of lacquering; and peak temperatures of 250C for a few minutes at a time! All on fully synthetic oils optimised for high temperature stability, and with sumps designed to get the oil out and back to the cooler as quickly as smoothly as possible.

[Heaveho]

Megaflow said:

With modern oil 125 degs C as a continuous temperature is fine, with peaks up to 135 degs for limited periods.

170 degrees would led to serious issues. Although fair play for understanding the temperatures are higher than water, most people see oil temperatures of 100 and panic, fit oil coolers, etc. or worse still fit and oil cooler just because they think the need one with no consideration to temperature at all!

Most people? Really? If people are concerned or interested enough to monitor the oil temp, I doubt they'd be daft enough not to have a reference for what's an upper limit. I suspect " most people " haven't got the first idea that oil temp is even remotely important to the wellbeing of their transport.

[Megaflow]

Heaveho said:

Megaflow said:

With modern oil 125 degs C as a continuous temperature is fine, with peaks up to 135 degs for limited periods.

170 degrees would led to serious issues. Although fair play for understanding the temperatures are higher than water, most people see oil temperatures of 100 and panic, fit oil coolers, etc. or worse still fit and oil cooler just because they think the need one with no consideration to temperature at all!

Most people? Really? If people are concerned or interested enough to monitor the oil temp, I doubt they'd be daft enough not to have a reference for what's an upper limit. I suspect " most people " haven't got the first idea that oil temp is even remotely important to the wellbeing of their transport.

I could have put that better. By most people I was referring to car enthusiast's, not the wider public, as you rightly say most of them could care less about the well being of their car.

I constantly amazed by the amount of people that modify cars by fitting things such as oil temperature gauges and crap themselves when it gets above 100 degrees C. Or worse, assume because the engine has been fettled in some way that is *must* have an oil cooler.

[lowdrag]

Just booked my C class in for a service. Can someone explain to me why, except for commercial reasons, the service indicator is based on time and not mileage? My last S202 was 12,000 mile intervals, whenever that arose, but adding a litre of oil changed the cleanliness and added another 2,000 so every 14,000. this new 204 diesel told me to have it serviced exactly one year after Mercedes serviced it at the factory before putting it on sale, where it sat without turning a wheel until I bought it two months later. Naturally, it "needed" a service on June 1st, one year on from the service but just 10 months into my ownership. Mileage was 7,000 since last service. I've waited another couple of months and at 12,000 miles it'll now be serviced, not before. The last car was run in at 100,000 and stopped using oil between services, and never a worry or problem. As a serial Merc owner for over 20 years (two cars until this one) I've been very casual about servicing, much against what is said here, yet reliability was superb. To me it smacks of pure commercialism, unless you can tell me different.

[va1o]

Once it's out of warranty I'd do the oil every 12 months/ 10k (i.e. in between services) to be on the safe side. £149 is indeed bonkers, you can either DIY or use somewhere like National Tyres who'll do it for under £50.

[sparks_E39]

My 5 Series is serviced when it asks for it, it's not on the dot every year. Last service was in June 2011 at 89k, it's booked in for this Friday for an oil and brake fluid service at 100k, which is going to cost around £200 at the indie.

[TheEnd]

Megaflow said:

I could have put that better. By most people I was referring to car enthusiast's, not the wider public, as you rightly say most of them could care less about the well being of their car.

I constantly amazed by the amount of people that modify cars by fitting things such as oil temperature gauges and crap themselves when it gets above 100 degrees C. Or worse, assume because the engine has been fettled in some way that is *must* have an oil cooler.

I'd see it a lot on the older M car forums, constant questions and panicking because they had an oil temp gauge and had no idea what was good or bad.
Those without a gauge never gave it a second thought.

[Sheepshanks]

lowdrag said:

Just booked my C class in for a service. Can someone explain to me why, except for commercial reasons, the service indicator is based on time and not mileage?

Mercedes said fleets didn't like the uncertainty of variable servicing. They did reduce the price (and scope) of the service when fixed interval was introduced though.

lowdrag said:

My last S202 was 12,000 mile intervals, whenever that arose, but adding a litre of oil changed the cleanliness and added another 2,000 so every 14,000.

So it was on variable servicing, not every 12000 miles. I can't recall hearing of a 12000 mile interval, but MB have messed around with servicing schedules a lot.

On pre-fixed interval it's usually 10K fixed, or 13K variable. To be on variable the oil quality has to be correctly set and then it can extend by 50%. There's still a time limit of 2 years. That's what my 2005 C270CDi does.

lowdrag said:

this new 204 diesel told me to have it serviced exactly one year after Mercedes serviced it at the factory before putting it on sale, where it sat without turning a wheel until I bought it two months later. Naturally, it "needed" a service on June 1st, one year on from the service but just 10 months into my ownership. Mileage was 7,000 since last service. I've waited another couple of months and at 12,000 miles it'll now be serviced, not before. The last car was run in at 100,000 and stopped using oil between services, and never a worry or problem. As a serial Merc owner for over 20 years (two cars until this one) I've been very casual about servicing, much against what is said here, yet reliability was superb. To me it smacks of pure commercialism, unless you can tell me different.

You new car should have been reset at PDI, and then it would have run for a year. The dealer messed up.

I've had my C Class for almost 10 years and its needed astonishingly little servicing. The snag with being casual about service intervals on a newer car is that it might mess up the Mobilo cover and could cause warranty / goodwill problems.