That is a waste of oil... but the oil you use is not designed for Diesel
engine... take a look... there is no CI4 rating or anything about diesel.
Stick to Mobil 1 Truck & SUV 5w40 or Shell RotellaT Synthetic 5w40 (much
cheaper). Or go Amsoil.
On newer diesel, change interval is 7500 miles or so...
[I said I change my oil every 4,000 miles]
> That is a waste of oil...
Well, what oil change interval would you recommend for a '91 300D
2.5 with 107,000 miles on it, then?
Anecdotally, five thousand miles between oil changes seems to be
a common interval with gasoline engines (and easy to keep track
of, to boot), so I figure knocking a thousand miless off of that
in the case of a diesel is rational.
(Wasn't a *three*-thousand-mile oil change interval recommended for
the W115 240D and 300D back in the '70s? I seem to remember reading
that in one of the car mags way back when...or "back in the day," as
the kids like to say.)
> but the oil you use is not designed for Diesel engine... take a
> look... there is no CI4 rating or anything about diesel.
> Stick to Mobil 1 Truck & SUV 5w40 or Shell RotellaT Synthetic 5w40
> (much cheaper). Or go Amsoil.
I'll look for 'em -- thanks -- but it's damned near impossible to
find my preferred grade of Mobil 1 (15W-50? something like that)
as it is. I don't think I'v ever seen "diesel rated" motor oil of
any brand for sale in my entire driving life. Maybe it's in the
fine print.
Geoff

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Tiger - 29 Aug 2006 00:25 GMT
Look in your manual... it would say for regular oil at 7500 miles... but
that is not recommended by diesel purists. With synthetic, I would go 7500
miles. If you do not want to use synthetic, then 3000 miles is what I would
recommends.
The old days with regular oil... 3000 miles is recommended. Modern engine
now burns so much cleaner so oil change interval is much higher.
Diesel rated synthetics starts with 5W... regular diesel oil starts with
15W. Walmart has Shell RotellaT Synthetic Oil in dark blue gallon
container... $3.99 a quart price... so you are paying $15.96 per gallon.
Diesel rated oil has better property to keep the soot in suspension and
control while regular oil or non-diesel synthetic do not have those
properties. Diesel engine also have much lower RPM and temperature operating
condition so diesel oil is not recommended for high performance gas engine.
The highest rated diesel oil is now CI4 Plus... CJ is coming in winter. If
you look at regular oil, you will see like CH or CF rating instead. CI4 is
designed for diesel car with EGR system... or otherwise the EGR will clog
up.
Gas engine now for MB now has 10000 miles interval with Synthetic oil. Older
MB had 7500 miles with regular oil... and the two decades ago would ask 5000
miles... The main thing is engine has changed so much that it ran so much
cleaner.
Dori A Schmetterling - 29 Aug 2006 18:42 GMT
Yes. Here is some more info on oils for diesel.
http://www.search.shell.com/cgi-bin/rsearch.cgi
DAS
For direct contact replace nospam with schmetterling
---
> Look in your manual... it would say for regular oil at 7500 miles... but
> that is not recommended by diesel purists. With synthetic, I would go 7500
[quoted text clipped - 23 lines]
> ask 5000 miles... The main thing is engine has changed so much that it ran
> so much cleaner.