Follow assist or change oil more often?

[PeterE320Cdi]

Following assist my car covered 18k mile since the last service which seems a long way without an oil change. Just interested in what other members do. Follow assist or change the oil at set intervals. I was thinking of changing the oil every 10k miles and then a B service every 30k.

 

[BlackC55]

Good oil at 10k is fine.

I always do my own cars at 5k just because I really look after my own.

 

[seymansey]

every 5k

 

[Rory]

I follow ASSYST, which for me means my 3 yr old C270CDi has been the dealer once in 3yrs, for an A service at 18K. It's showing that it wil need a B service at 35K, but has to have an MOT in a couple of weeks, when it will apparently also need the brake fluid and coolant changing.

There is a thread from a guy who had his oil in an MB van analysed at around 20K and the result showed it was still good.

 

[230K]

Hi

I have voted for every 10K thats what i do Mobil 1 change at or less than 10K intervals. Once i stretched it to 12K but there was still 2.5K left according to assyst.

Good Luck

230K

 

[IanA2]

I always do my own cars at 5k just because I really look after my own.

Interesting....what would you do if you only covered say 3K in a year..?

 

[BlackC55]

I do much more than that so its not really an issue.

But IF I did I would still keep to 5k

 

[IanA2]

Even if it meant 18mths between changes...?

 

[BlackC55]

Yes.

 

[IanA2]

That's interesting, I heard all sorts of advice over the years, from every six months to every 3k !!

I was never sure of the temporal degradation issues, I suppose modern synthetics make them less of an issue.

 

[merc man]

If it was left to mercedes i wonder what state my car would be in, the w203 has had so many faults i feel like a c-class doctor and can just about fix every fault! so i use my judgement and change it every 10k or around that mark, a full flush with a filter change and then i add some new oil and let that find its way out then i add the new oil.

mobil 1 is a bit expensive, it costs more than gold, i remeber the good old ford days at £10 for 5 litres! did the job!

 

[Will]

My 190E did less than 1K miles in the last year although it still gets a proper service and an oil change regardless.

Will

 

[Dieselman]

If really this bothered why not fit a bypass filter, then oil changes are not necessary.

 

[fuzzer]

Mercedes assyst just makes it cheap for companies to lease the car over 3 years and 60k . It does no favours for the car.

 

[karlefr]

I have changed the oil every 20000 km and I did over 350,000 km with no repairs whatsoever to the engine ( W124 300T 24V ). And I did love the car! This car is still running fine!
A 5k oil change only keeps the oil-companies happy!
Such frequent changes are totally overrated!

 

[stats007]

It depends on the engine in question and how it's driven. I would go with annually or 5k miles.

 

[Parrotman]

If it gives you peace of mind then change the oil and filters at whatever intervals you think best.

With my 2 previous cars I changed the oil once a year regardless of mileage. The 1st car, a Ford Sierra 2L Estate I had for 10 years and done 155,000 miles when I sold it on without any engine problems apart from valve seals. The 2nd car, a Nissan Primera 2L Estate also had for 10 years, and done 135,000 miles when I sold it on earlier this year and again with no engine problems ( just so reliable a motor ). Apart from the Sierra's valve seals neither car burnt/used oil at any noticeable rate. Used Castrol GTX for the former and Castrol Magnatex for the latter.

My MB had a major service in February and come next year will get an oil change ( using recommended oil ) as with previous cars. In relative terms the extra cost is immaterial nor expensive.

 

[verytalldave]

Full synthetics like Mobil One are OK for up to 20,000 miles of normal / motorway driving. Constant regular stop/start driving would reduce that to about 10,000 miles. Non or semi synthetics halve those figures.

 

[Dieselman]

With my 2 previous cars I changed the oil once a year regardless of mileage. The 1st car, a Ford Sierra 2L Estate I had for 10 years and done 155,000 miles when I sold it on without any engine problems apart from valve seals. The 2nd car, a Nissan Primera 2L Estate also had for 10 years, and done 135,000 miles when I sold it on earlier this year and again with no engine problems ( just so reliable a motor ). Apart from the Sierra's valve seals neither car burnt/used oil at any noticeable rate. Used Castrol GTX for the former and Castrol Magnatex for the latter.

So you ran the cars well past their recommended oil change interval and used low grade oil.
It would have been interesting to have an oil analysis performed on your oil.

It just goes to show how tolerant modern engines are.

 

[Dieselman]

Full synthetics like Mobil One are OK for up to 20,000 miles of normal / motorway driving. Constant regular stop/start driving would reduce that to about 10,000 miles. Non or semi synthetics halve those figures.

Is this proven or an opinion.?

I've read reports of semi-synth going twice it's recommended drain interval and still being in very good shape, with low acid and high base number, and the engines in question being stripped at 250K miles and still within manufacturing tolerances.

The only proper way to ascertain the oil quality is by analysis. Different viscosities will behave differently.
Modern Long Life oils are thinner to allow more particle matter to be suspended before too much thickening happens.
The down side is less protection due to the viscosity reduction.