Synthetic oil change interval

[patrick flowers]

>
> Thanks to all for their responses. I will study them and make a
> decision on what to use. I feel that the synthetics will stand up
> better to the heat and loads that the GMC lives with. I do think
> think that the recommended oil change that Mobil quotes is a little
> too long. I think that maybe half of that would be better as the
> acids need to be removed from the engines. I do agree with the
> changing the filter at the normal oil change mileage.

Unless you're a full-timer, the 25,000 mile oil change interval could
equate to several years use. I would want to change the oil at least
twice a year - in the fall when I winterize and in the spring before
heavy use again. If my coach was used more during the winter, maybe I'd
be more comfortable with once a year - no more.

Of course, I'm also a devoted user of Castrol brand dead dinosaur
byproducts. I've never quite been convinced that the touted advantages
of synthetic oils were worth the additional costs. After this thread,
maybe I'll give Mobil 1 a try. Still, I don't think I'd ever be
comfortable leaving the same oil in an engine for longer than one year.
Oil(of any variety) is cheaper than engines.

Patrick
- --
Patrick Flowers
Mailtoatri63

The GMC Motorhome Page
http://www.gmcmotorhome.com

 

[john szalay]

>>
>> decision on what to use. I feel that the synthetics will stand up
>> better to the heat and loads that the GMC lives with. I do think
>> think that the recommended oil change that Mobil quotes is a little
>> too long. I think that maybe half of that would be better as the
>> acids need to be removed from the engines.

I,ve used Mobil 1 for years in my auto, and am very satisfied with
the results, the 78 350 chevy has 275,000 miles on it and the engine is
still in great shape, I,ve had the valve covers off and its clean as new
no tar or varnish.
The Acid problem appears to much less with the syn. oils since the
formulation does not contain the same make up as mineral based oils,
If I read the information correctly, the acid is formed when condensation
drains down into the oil and combines with the chemicals in the mineral
based oil. those chemicals are not present in the syn oils.
But all oils do, pick up ash and waste materials and get dirty.
so change intervals can be farther apart, but are still required.

>>I agree with the
>> changing the filter at the normal oil change mileage.
>

as do I, filter and add on regular basis.


>Unless you're a full-timer, the 25,000 mile oil change interval could
>equate to several years use. I would want to change the oil at least
>twice a year - in the fall when I winterize and in the spring before
>heavy use again.

Mobil recommends atleast one per year or 25,000 miles

>maybe I'll give Mobil 1 a try. Still, I don't think I'd ever be
>comfortable leaving the same oil in an engine for longer than one year.
>Oil(of any variety) is cheaper than engines.
>

ONE CAVET.. IF your engine is loose, worn, or burns oil, DO NOT USE SYN OIL
it will go right thru it. also DO NOT USE in a brand new engine, until
it has been broken in, and the break-in oil has been changed
Mobil recommends a break-in of at least 10,000 miles before switching
to syn. oil. Unless they have changed their guidelines recently, that is.

I do not currently use Mobil 1 in our GMC, because of the miles it has
on it. BUT when it comes time to rebuild it, after the break-in period
I will be putting Mobil 1 in it.

John Szalay
73 GMC