DIYbanter - View Single Post - Synthetic oil and follow-up oil changes?

Tony[_19_]

wrote:
On Wed, 2 Sep 2009 05:56:12 -0700 (PDT), wrote:

On Sep 1, 3:08 pm, Phisherman wrote:
On Mon, 31 Aug 2009 13:08:11 -0700 (PDT), RickH

wrote:
I went to the Jiffy Lube this weekend and thought I'd splurge and put
in some Castrol Syntec as they were having a sale on it, (vehicle 2007
Toyota RAV4). When I asked for the Syntec the guy said that once you
go to a synthetic oil, you should stay on it and not go back to
regular oil. Well since the the regular cost of a Syntec oil change
is double, I said forget it and just put in regular oil.
First, is it true what the guy said about it being "bad" to go back to
regular oil after using synthetic? If so, why? I had a car in early
the 90's that loved Mobile 1, ran great on it, I dont remember
dedicating that car to Mobile 1 though for all time, I'm sure I used
all different oils.
Thanks
Rick
Yes it is true. It is always best to stay with the same oil, same
brand. If you buy a used car, continue with the same oil as the
previous owner. Engines may run differently, depending on viscosity,
detergents, and additives. It is best to stick with the
manufacturer's recommendations, although I've always changed oil every
3,000 miles. Oil breaks down over time, synthetics also but slower.
As a DIY, I would expect you would change your own oil--it's a fast
and easy job and allows you to inspect for possible problems
elsewhere.
And I would disagree. What makes the one specific oil that the
previous owner happened to choose so special? What if he said he used
several brands, would you walk away from buying the car because it's
gonna blow up soon?

With almost all modern cars, the manufacturer lists many oils of
differing viscosity and brands that may be used. At any oil
change, you could use any one of them. All oils are tested
extensively in actual engines to meet API standards, which are most
important and listed on the container. Individual auto
manufacturers may have their own specs, which exceed the API ones.
But still there are usually many oils, multiple brands that will meet
those specs. I'd be suspicious that auto companies that say you can
only use Brand X are doing it not because the engine won't last just
as long, but because they have some deal with that oil company, eg
they get a discount on their purchases by exclusively recommending
only that brand.

Just my take - but if a vehicle has had the same premium oil used for
every oil change, chances are pretty good the owner has been pretty
"anal" about maintenance as a whole - ie . you are likely buying
something that's been looked after.

If it's had the "flavor of the week" for oil, chances are pretty good
the owner was a chiseler who cut corners wherever he could
maintenance-wise.

I got over 200,000 on my van using walmart brand cheap oil and it still
ran great when I traded it in. There are "chiselers" and there are
"suckers" when buying motor oil.

I buy the cheap stuff just so it complies with the factory warranty.
Others buy the brand name advertised stuff and pay for their
advertising. I choose not to pay for their advertising.

As far as not using the same brand oil all the time, or synthetic all
the time... that is simply the dumbest thing I ever heard! The only
time that holds true is in older motors that had been run on non
detergent oil then changing to HD, high detergent oil.