From: Steve Barker on
If you insist on using the $ynthetics then the change interval is 3,000
miles. It doesn't matter if you pour in liquid gold, it still gets dirty in
the same length of time.

Steve Barker

YOU should be the one
controlling YOUR car.
Check out:

"Eeyore" <rabbitsfriendsandrelations(a)> wrote in message
> So what change interval do you recommend for vehicles that use synthetic
> oil ?
> Graham

From: C. E. White on
----- Original Message -----
From: "Steve Barker" <ichasetrains(a)>
Sent: Wednesday, March 28, 2007 10:06 PM
Subject: Re: Automakers Lengthen Oil Change Intervals

>I run it year 'round in Kansas. Still no problems. There's just not
>that much difference, except the 30w lubes better hot.

Why do you say that? Back in the 70's multi-weight oils got a bad
reputation becasue some of the early 10W40 oils tended to break down
and in some cases you ended up with some sort of goop in the engine.
That was long ago. Modern API certified 5W30 and 10W30 oils have never
had that sort of problem. At normal "high" oil operating temperatures
(around 100 degrees C), straight 30 weight Havoline has a viscosity of
10.3 cSt. while both 5w30 and 10w30 Havoline have a viscosity of 9.7
cSt - less than 6% different (the acceptable range for 30 weight oil
is 9.3 to 12.5 cSt). At 40 degrees C (104 F), the straight 30 weight
has a viscosity over 80 cSt while the 5W30's viscosity is less than 60
cSt (both are still far thicker than either oil at 100 C). During a
normal cold start straight 30 weight oil is much thicker than 5W30
oil - not a good thing. Once an engine is warmed up, the 5W30 and
straight 30 weight have to meet the same viscosity requirements. So
where is the advantage of straight 30 weight oil?


From: SMS on
HLS(a)nospam.nix wrote:
> "SMS" <scharf.steven(a)> wrote in message
> news:460b2277$0$27169$742ec2ed(a)
>> jwardl wrote:
>>> How can oil be changed TOO often? Personally, think I'll stick with
> 3/3k.
>> There is some point at which changing it more often has absolutely no
>> benefit at all in terms of engine wear. It's not 500 miles, 1000 miles,
>> or even 3000 miles. It's probably somewhere around 7000-8000, but to be
>> absolutely safe, many people change it at 5000. 3000 is an absolute
>> waste of money, no study has shown any benefit to such frequent oil
> changes.
> You are repeating yourself. Show me data from a reliable source. Data, not
> claims.

You're the one claiming that changing oil far more often than the
manufacturer, or any reputable mechanic, says is necessary. It's up to
you to provide the data.

There is plenty of data that shows no benefit from 3000 mile oil
changes. Start with the CR study of a few years ago. All stop and go
driving. Fewer cold starts, but more frequent oil changes don't help
reduce the wear from cold starts, when using multi-weight oil.

From: HLS on

"C. E. White" <cewhite3(a)> wrote in message
\A copy of the old CR study is at
> . I know it is old and
> since they used taxis, they don't have as many cold starts per mile as
> a typical Consumer....

Thanks, Ed...
I quote from this report
"On the basis of our test results, we think that the commonly recommended
3,000-mile oil-change interval is conservative"

I am very conservative.

They also found no difference in performance between synthetics and
petroleum refined oils.
Not too surprising to me.

And when they tried to run Mobil 1 to 12, 000 miles, two of the three test
engines failed
prematurely, although they could not pin the failure on the Mobil 1.

It is some data, if not complete, and for this reference I thank you.

I know that data is out there. I found papers cited from test organizations
like Southwest Laboratories
but I have no access to them, and will not pay what they ask to get them. I
am interested, but not
THAT interested.

I will continue to use refined oils of high quality, UNLESS the manufacturer
of my car throws
warranty issues up in my face, and will continue to use frequent oil
changes. I have, from
my own calculations, found that it doesnt cost very much and -if it doesnt
do any good - it
certainly doesnt hurt anything.

From: Mike on

"Brent P" <tetraethylleadREMOVETHIS(a)> wrote in message
> In article <5e7m03h7jbpfh502qbt6nepp7ic8rsh94e(a)>, clare at
> wrote:
>> Minimum 20 minutes to get the oil to full operating temperature, and
>> then about another 10 minutes for every day of short run cold morning,
> <snip>
> When your coolant has reached OT and the thermostat is open, the oil has
> reached operating temperature some time before that. It's basic heat
> transfer. If it had not, the coolant and engine block would still be
> warming the oil and the Tstat would remain close.

Wrong. The oil takes much longer to reach operating temp than the
coolant. Want proof, just wait till the thermostat opens and feel the bottom
of the oil pan, still not hot is it ?