There is NEVER a "cost benifit" to using sythetic oil. I hope you haven't
been trying to go 15,000 between changes? Switching back and forth isn't a
good idea IMHO but if I was going to switch back, I'd change to dino oil
and then change it again in about 1000 miles to help "flush out" whatever
was left and then change every 3000 there after.
No problem. I feel it's safer to do it this way in case the additive
packages don't play well together and of course if you had a turbo car etc,
my advice would be different. For this car in your application, dino oil is
a better solution. You could probably skip the extra change at 1000 miles
if $20 is going to get in you way. I'm always amazed at people trying to
save $20 on the service of a $20,000 car....
Sure there's a cost benefit of using a "real" synthetic oil under
certain conditions. If it's freezing (think Minnesota) it should help
with startup. If it's ridiculously hot, it can help if the cooling
system fails. Synthetic is excellent for forced induction engines.
It's also getting to the point where certain manufacturers effectively
mandate the use of synthetic oils. BMW, Porsche, and Mercedes-Benz
use Valvoline or Mobil 1 synthetics from the factory. Some high
performance engines (Corvettes and Vipers) come with synthetic
from the factory.
There is a cost benefit if your time is worth something. I have been
using AMSOIL for over 20 years in all types of vehicles and typically do
10,000 mile oil changes - about almost twice what I would be doing with
dino oil. When I recently sold my Hardbody with 120k miles, the buyers
jaw dropped when he opened the oil fill on the valve cover as it looked
brand new inside. He was a mechanic BTW. None of my vehicles have ever
had any problems with any lubricated part. Granted, it is possible that
changing dino oil at those intervals *may* achieve the same results with
less piece of mind (unless you own a V6 Toyota sludg monster anyhow)
Even if it cost me an extra $20 for the oil change, the fact that I only
have to mess with it 1/2 as much is well worth it to me.
From your post, you appear to be on the 3000 mile oil change camp. This
is definitely an artifact form the 60's and 70's where engine tolerances
sucked and oil was not nearly as good as it is today and is completely
unecessary in today's vehicles (again, unless you have a Toyota V6).
Yes, it's perfectly safe to switch back (and forth again) if you want.
The oils are fully compatible with each other. If you change oil at
the usual too often intervals there is no real benefit to synthetic
except for really cold places if you have trouble cranking on regular
Elbridge Gerry, of Massachusetts:
"What, sir, is the use of militia? It is to prevent the
establishment of a standing army, the bane of liberty. . .
Whenever Government means to invade the rights and liberties of
the people, they always attempt to destroy the militia, in order
to raise a standing army upon its ruins." -- Debate, U.S. House
of Representatives, August 17, 1789
Maybe it's just that us AZ guys think alike, but the answer is "yes" - there
are no risks at all with switching from synthetic to dino oil. In older
cars, especially those with an uncertain oil change history or lots of hours
in hot environments (like Arizona, for example), switching from dino to
synthetic can dissolve deposits that old and hardened seals were depending
on. The affected seals can then leak - the same applies to using "engine
flush" products, as I found out the hard way when I was young and more
Synthetic and dino are totally compatable, and blends are available. Some of
my friends use one quart of synthetic when they change their oil, and they
probably get most of the benefits of synthetic at a much lower price. In my
mind, the main value in synthetic is the much higher detergency. If oil
changes are kept up with dino oil, the engine itself stays clean inside, but
PCV passages and throttle bodies build up deposits that can be expected to
cause trouble eventually. In my 85 turbo Volvo, the turbo is still going
strong at 230K miles because of the regular oil changes, but I've had the
throttle body off for cleaning several times. I always have to use a drill
bit to clean the vacuum nipples when I wait more than a year or two. Last
year the actual hoses in the crankcase ventilation system plugged up with
deposits (these are like 3/8" hoses!) and I had to replace them. Lost 3
quarts of oil blown all over the engine when that happened on the freeway -
about a pint a minute. The Volvo gurus tell me these things don't happen
On Mon, 20 Dec 2004 13:02:47 -0500, "Daniel J. Stern"
I use Castrol or Valvoline dino in my cars, change oil and filter (
Motorcraft Fl400-S) every 90 days or 3,000 miles, and have never had
an engine problem related to oil. n e v e r.
Go figure. If you want to spend the extra $ on synthetic, it's your
money, be my guest.
I wave my left arm in a semicircle eight times every hour on the hour
between 8AM and 8PM weekdays (10AM and 12AM weekends) and have never been
attacked by a pink crocodile. n e v e r. Go figure.
Correlation does not imply causation.
Well, let's do the math, shall we?
Castrol or Valvoline's at about $2.10/qt including tax.
Mobil-1's at about $5.10/qt including tax.
An FL400S filter is about $4.20 including tax.
Let's say your car takes 5 quarts and you want to drive it for 60,000
If you're changing dino oil every 3k miles, that's 20 filters and 100
quarts, so $210 worth of oil and $84 worth of filters. Total oil costs in
60k miles, assuming the engine consumes none: $294.
If you're changing Mobil-1 every 9k miles, that's 6 filters and 30 quarts,
so $153 worth of oil and $25.20 worth of filters. Total oil costs in 60k
miles, assuming the engine consumes none: $178.20.
"Extra money" spent on synthetic: one hundred fifteen undollars and eighty
This is a pretty manufactured comparison. As a point of fact, I have never
than $1.00 per quart of dino oil. I wait until it goes on sale. Dan is
used to buying stuff at places like NAPA and doesen't realize that the
people regularly discount dino oil, sometimes down to 49 cents a quart with
I would be happy to post scans of my last 5-6 cash register receipts that
show oil purchases at below $1.00 a quart if someone here wants to continue
the rediculous claim that dino oil costs $2.10 a quart. And this is from
since I buy as many cases as I can at the $1.00 a quart cost when it does go
on sale. And this is name brand Chevron or Havoline oil also.
By contrast it is -extremely- rare for synthetic oil to be discounted - and
is discounted, invariably it is only via rebate - and the fine print only
allows 1 rebate
per year per household. And also it isn't discounted much.
What if there is no Checkers/Kragen/Schucks stores in the
I only recognize the name from seeing it on TV.
We've got NAPA and CarQuest and a few department stores.
The cheapest I've seen the house brand (Valvoline) at NAPA and
CarQuest is $.99 a quart.
Don't know about the Chevron but the Havoline, yeesh, what tar!
And when I say tar, I mean experience from being inside engines
that has had it's oil changed religiously every 3K miles and the
owners have used Havoline exclusively since the vehicle was new.
NAPA has Mobil 1 on sale for the month of December for $3.99 a
quart, Walmart almost always has 5 quart jugs for (IIRC) $19.88,
It would seem for some people, it would take just as much
manufacturing to achieve the price point you claim as it would
for Daniel's claim.
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