Oil changes on 500SL

[IanA2]

I've been getting two lots of advice on this. Some say 6 months or 6000 miles and others 3 months or 3000 miles. Who is right? Any ideas? Thanks in advance.

 

[Brian WH]

I've been getting two lots of advice on this. Some say 6 months or 6000 miles and others 3 months or 3000 miles. Who is right? Any ideas? Thanks in advance.

I don't know your vehicle, but 3000 miles seems too short a period mate.

6000 miles or 6 months would seem OK, it depends a lot on how you drive it. If you drive like a Nun then this is OK, if you drive like a Maniac then you should shorten the period accordingly.

Someone with a 500 SL handbook should tell you, or ask a dealer?


Moving to engine section.

 

[IanA2]

Thanks for that, I've scoured the handbook, no result, I've asked stealers and dealers, diff responses. It's a five litre V8 which is why I think there might be something in the 3000 mile idea.

 

[jaymanek]

6000 miles is what it said in the service booklet of my 1996 SL500....

 

[Dieselman]

6000 miles or 6 months would seem OK, it depends a lot on how you drive it. If you drive like a Nun then this is OK, if you drive like a Maniac then you should shorten the period accordingly.

This is the wrong way round. Cars driven too softly never evaporate the petrol out of the oil so wear the engine harder.

 

[Brian WH]

This is the wrong way round. Cars driven too softly never evaporate the petrol out of the oil so wear the engine harder.

I don't agree that this applies on a modern engine mate.

On an old worn engine then yes, but screaming it around the streets will still do it more harm.

 

[Will]

This is the wrong way round. Cars driven too softly never evaporate the petrol out of the oil so wear the engine harder.

I would have thought that this is more relative to the type of journeys the vehicle is subjected to?

Vehicles frequently used on short journeys may not reach full operating temperature, hence as you say petrol etc does not evaporate. If the vehicle is driven 'hard' on such journeys, this can only accelerate wear on the engine and contamination of the oil? Surely the vehicle that is driven hard would be more deserving of frequent oil changes?

If the vehicle is used for longer journeys, eg, 20-30 miles or more, the vehicle will surely reach full operating temperature whether it driven hard or not?

Makes sense to me.

 

[Dieselman]

I would have thought that this is more relative to the type of journeys the vehicle is subjected to?

Vehicles frequently used on short journeys may not reach full operating temperature, hence as you say petrol etc does not evaporate. If the vehicle is driven 'hard' on such journeys, this can only accelerate wear on the engine and contamination of the oil? Surely the vehicle that is driven hard would be more deserving of frequent oil changes?

If the vehicle is used for longer journeys, eg, 20-30 miles or more, the vehicle will surely reach full operating temperature whether it driven hard or not?

Makes sense to me.

Who said anything about driving an engine hard from cold. Also journey length wasn't mentioned.
Most people who drive like Nuns drive slowly and for short journeys. This type of driving definately causes bore glazing and oil dilution.
An engine serviced properly and driven using the full rev range will often outlast one driven too gently.

A collegue of mine went to see an E230 with 70K on the clock. The engine was totally worn out due to exactly the reasons stated. This had been a company directors car and all stamps were in the book.

 

[glojo]

3000 or 6000 with a few disagreements.

Nice question Ian, I will play umpire and say 4500 = halfway between.

If you can afford the oil changes then changing to frequently surely cannot be as harmful as not doing it enough?

I wonder how much it would cost to have the oil examined at say 6000 miles?

Is it available locally as I imagine you would soon recoup the cost if you could actually safely extend the oil change intervals?

Good luck,
John

 

[Will]

Who said anything about driving an engine hard from cold. Also journey length wasn't mentioned.
Most people who drive like Nuns drive slowly and for short journeys. This type of driving definately causes bore glazing and oil dilution.
An engine serviced properly and driven using the full rev range will often outlast one driven too gently.

A collegue of mine went to see an E230 with 70K on the clock. The engine was totally worn out due to exactly the reasons stated. This had been a company directors car and all stamps were in the book.

You simply stated that 'Cars driven too softly never evaporate the petrol out of the oil so wear the engine harder.'

All things being equal (temperature, journey time - either short or long) I can't see this being the case.

Short journey, cold start - What's better, thrashing the engine like a maniac or driving more softly?

Long journey (eg, 20-30 miles+) - The engine will reach full operating temperature and hence the petrol etc will evaporate, whether the car is driven soft or hard. Other than the fact that an engine driven hard before it has had time to warm up will surely wear quicker, what's the difference?

I'd still say that on balance the engine driven hard, (especially if this is from cold or with frequent short journeys) or like a 'maniac' as Brian originally mentioned would be more in need of a oil change due to the increased stress the engine is put under. There's a difference between driving like a 'maniac' and occasionally giving the engine a good workout, with a little mechanical sympathy

 

[Dieselman]

Is there any chance we could introduce a few more variables into this thread? There have been more U turns and shifting of goalposts than Tony Blair could manage.

Fact: engines driven gently take longer to warm up so have a greater fuel and water soak into the sump.

Fact: engines driven gently, the oil may never reach high enough temperatures for the dilutants to boil off, even on longer journeys.

Fact: engines driven gently tend to suffer more bore glazing which in turn produces blow by which in turn increases oil dilution.

Fact: engines thrashed from cold suffer damage, but who said anything about cold starts?

fact: engine oil requires changing as much as a result of time as a result of mileage. This is because of the reasons mentioned above...The oil doesn't break down it becomes poluted with fuel.

Your argument would say that because "Doris" only drives gently for 2000 miles per year, her car can go five years before it requires an oil change, given 10000 change interval, whereas Mr Reppy-Boy needs his changing every 5000 miles even though he covers 20000 per year.
This is simply not so and the ASSYST system will work in exactly the opposite fashion for the reasons mentioned.

Can we please stick to some constants and preferrably something scientific?

 

[Dieselman]

I've been getting two lots of advice on this. Some say 6 months or 6000 miles and others 3 months or 3000 miles. Who is right? Any ideas? Thanks in advance.

Getting back on track.

You will probably find that earlier cars have a shorter oil change periods whereas later cars are longer.
This is probably due to two things. Oil quality and fuel quality. Both have moved on so oils protect better and fuels don't polute as much.

Depending on your mileage I would go for a quality oil changed at either 6000 miles or annually or half annually if the mileage is very low.

 

[Will]

Is there any chance we could introduce a few more variables into this thread? There have been more U turns and shifting of goalposts than Tony Blair could manage.

Fact: engines driven gently take longer to warm up so have a greater fuel and water soak into the sump.

Fact: engines driven gently, the oil may never reach high enough temperatures for the dilutants to boil off, even on longer journeys.

Fact: engines driven gently tend to suffer more bore glazing which in turn produces blow by which in turn increases oil dilution.

Fact: engines thrashed from cold suffer damage, but who said anything about cold starts?

fact: engine oil requires changing as much as a result of time as a result of mileage. This is because of the reasons mentioned above...The oil doesn't break down it becomes poluted with fuel.

Your argument would say that because "Doris" only drives gently for 2000 miles per year, her car can go five years before it requires an oil change, given 10000 change interval, whereas Mr Reppy-Boy needs his changing every 5000 miles even though he covers 20000 per year.
This is simply not so and the ASSYST system will work in exactly the opposite fashion for the reasons mentioned.

Can we please stick to some constants and preferrably something scientific?

Who's changing goalposts now You seem to be making several assumptions of your own. What U-turns has anyone made in this discussion?

I've never stated that oil change intervals should be increased because of lower mileage use! Even a service booklet would tell you this.

As I have mentioned, engines driven with some mechanical sympathy will be in the best of health. Driving hard like a 'maniac' (which is what the first reply by Brian actually said) is likely to accelerate wear, even more so if this is from cold. All your 'facts' are plausable, but as has been said, cold starts and short journeys, combined with un-sympathetical driving will no doubt lead to greater engine wear.

Your example of the repmobile and 20K miles per year is exactly my point. If he is covering 80+ miles per day, does he really need to thrash the living daylights out of his car to ensure that his oil does not become diluted? I would have thought that driven in a typical fashion the oil will get plenty of opportunity to reach full operating temperature?

And as for Ian's original question, I'll agree with Dieselman's advice. Only adding that I would change the oil as frequently as you wish/can afford! If you want to change it more frequently than is specified in the service book, go for it - it can't hurt.

 

[Brian WH]

At least we all agree on the answer to the question asked.

 

[Dieselman]

Who's changing goalposts now You seem to be making several assumptions of your own. What U-turns has anyone made in this discussion?

Err.. You have. You introduced variables such as thrashing the engine from a cold start and that IanAlexander2 drives 80+ miles per day.
I must have missed something but I don't see those comments in the original question.

I've never stated that oil change intervals should be increased because of lower mileage use! Even a service booklet would tell you this.

Your comment here states that engines driven hard should have reduced oil change intervals. It equates to the same thing. More politician speak.

"I'd still say that on balance the engine driven hard, (especially if this is from cold or with frequent short journeys) or like a 'maniac' as Brian originally mentioned would be more in need of a oil change due to the increased stress the engine is put under."

As I have mentioned, engines driven with some mechanical sympathy will be in the best of health. Driving hard like a 'maniac' (which is what the first reply by Brian actually said) is likely to accelerate wear, even more so if this is from cold. All your 'facts' are plausable, but as has been said, cold starts and short journeys, combined with un-sympathetical driving will no doubt lead to greater engine wear.

There's that "FROM COLD" statement again.

Your example of the repmobile and 20K miles per year is exactly my point. If he is covering 80+ miles per day, does he really need to thrash the living daylights out of his car to ensure that his oil does not become diluted? I would have thought that driven in a typical fashion the oil will get plenty of opportunity to reach full operating temperature?

There's the 80+ miles per day. Only you have mentioned that.

And Brian said
"If you drive like a Nun then this is OK, if you drive like a Maniac then you should shorten the period accordingly."

I still don't agree and seemingly neither do you.

Quote Will
"Your example of the repmobile and 20K miles per year is exactly my point."

If you recall I said that an engine driven TOO SOFTLY will require more frequent oil changes.
That's a contradiction of your earlier comments. First you say that an engine driven harder requires shorter oil change intervals, now it's longer, as indicated by ASSYST.
I'm confused.

Seriously I don't wish to fall out over this but I have been confused by the comments made.

 

[Brian WH]

By the way - My Nun drives properly and doesn't just do local trips, as she goes to Rome once a quarter. She is therefore driving as the car was intended, and not thrashing it about the local roads like a maniac.

 

[Will]

Err.. You have. You introduced variables such as thrashing the engine from a cold start and that IanAlexander2 drives 80+ miles per day.
I must have missed something but I don't see those comments in the original question.

Your argument would say that because "Doris" only drives gently for 2000 miles per year, her car can go five years before it requires an oil change, given 10000 change interval, whereas Mr Reppy-Boy needs his changing every 5000 miles even though he covers 20000 per year.

The 'variable' of 80 odd miles per day is derived from you 'variable' of 20K miles per year usage.

Your comment here states that engines driven hard should have reduced oil change intervals. It equates to the same thing. More politician speak.

"I'd still say that on balance the engine driven hard, (especially if this is from cold or with frequent short journeys) or like a 'maniac' as Brian originally mentioned would be more in need of a oil change due to the increased stress the engine is put under."



There's that "FROM COLD" statement again.

There's the 80+ miles per day. Only you have mentioned that.

Again, the 80 miles is from your variable. I will stand by my statement! If a engine is driven excessively hard, even more so if is driven hard from a cold start, it will be susceptable to greater wear - and hence would require more frequent oil changes. This is in keeping with the original question and response from Brian - driving habits can certainly influence wear on an engine.

And Brian said
"If you drive like a Nun then this is OK, if you drive like a Maniac then you should shorten the period accordingly."

I still don't agree and seemingly neither do you.

Quote Will
"Your example of the repmobile and 20K miles per year is exactly my point."

If you recall I said that an engine driven TOO SOFTLY will require more frequent oil changes.
That's a contradiction of your earlier comments. First you say that an engine driven harder requires shorter oil change intervals, now it's longer, as indicated by ASSYST.
I'm confused.

You simply stated that 'Cars driven too softly never evaporate the petrol out of the oil so wear the engine harder.'

And I said:

All things being equal (temperature, journey time - either short or long) I can't see this being the case.

Short journey, cold start - What's better, thrashing the engine like a maniac or driving more softly?

Long journey (eg, 20-30 miles+) - The engine will reach full operating temperature and hence the petrol etc will evaporate, whether the car is driven soft or hard. Other than the fact that an engine driven hard before it has had time to warm up will surely wear quicker, what's the difference?

I do agree that if a car is used for exceptionally low mileage it is beneficial to change the oil on time regardless, the more frequently the better, but I can't see where this incredibly long discussion has come from? The overall point, which I have mentioned several times, is that driving like a 'maniac' (as per the original reply) is not going to prolong the life of an engine. Regarding all the comments regarding politics, goalposts, U-turns, Tony Blair, "Doris", Mr Reppy-Boy etc - now who's going off topic?

You seem to have plenty of time to dedicate to arguing - I have things to do, so whatever basically!

Seriously I don't wish to fall out over this but I have been confused by the comments made.

Me neither, but I do wish you wouldn't be so awkward!

All the best,

Will