Evidently, you have reaped the benefit of taking good care of your vehicles.
Whether you use conventional or synthetic, changing your oil is important.
Here are some of the reasons why I think synthetic oil is much better:

1. My own experience - I have been using synthetic oil for about 10 years
now. Every vehicle that I have had in that time period has shown minimal
wear and lasted several hundreds of thousands of miles (I drive an awful
lot) with only minor maintenance. Although it may appear that the parts on
your engine have not worn out, they do in fact wear. A car that has driven
a hundred thousand miles on conventional oil shows significant loss in
compression in the cylinders due to wear on the piston rings whereas a car
driven the same distance on synthetic shows much less wear. This does not
mean that the car using conventional oil is no longer useful or that it even
needs the engine rebuilt. It simply means that the engine is no longer
quite as efficient and powerful as is used to be. My last car had so little
engine wear after 300,000 miles that my mechanic said that it looked more
like it only had 20,000 miles on it. He attributed it to the fact that I
use synthetic oil. Three years ago, I gave it to my brother-in-law with
328,000 miles on it. He is still driving it. And get this - It's not an
expensive car, it's a Dodge Shadow ES. I also notice that my engine runs a
lot smoother with synthetic oil. Maybe that does or does not mean anything
when it comes to how long the engine will last but it sure sounds better.

2. Planes - Yep, planes. This is where synthetic oil actually first started
being used - - - in airplane engines. Conventional oil could not hack the
harsh environment of some aircraft engines so synthetic oil was developed
for use in aircraft. I have had a chance to talk to some of the engineers
at Lockheed and one of them gave me a real good lesson in why synthetic oil
was so much better. He convinced me.

3. Test after test after test - There have been numerous independent test
that have shown time and time again that synthetic oil is superior. If you
want some more info on why it is better, you can go to
http://www.dirtroad.com/oil2.htm.

4. If conventional oil was just as good as synthetic, why do most NASCAR
teams use synthetic and why do some auto manufacturers put synthetic oil in
some of their new performance cars and require it for their warranties to
remain valid?

The fact is, that synthetic oils are better. Yes, they are more expensive
but they are also better.


"-v-" wrote in message
om...
None ever wore out. If you change your oil and filters regularly there is
no
real advantage to synthetic oil.

"Frank Taylor, Jr." wrote in message
...
It would have made your engines last longer than they they did with
conventional oil.

I've never had and engine failure either. That's not the point. The
point
is, do you want your rings and bearings worn out and ready for the junk
yard
at 150,000 miles or at 500,000 miles.


"-v-" wrote in message
om...

"Frank Taylor, Jr." wrote in message
...
Synthetic oil is definitely much better than conventional oil. My
boat
has
a Volvo engine and I use nothing but synthetic in the engine and in
the
outdrive. I also use nothing but synthetic in my truck.

The way I see it, if you take care of it, it will take care of you.

Frank

I have been driving for 34 years and boating for 14 years. I have
never
used
synthetic oil.

I have never had an engine failure except one raw water cooled inboard
that
corroded out after 6 years and 1300 hours in salt water.

What would synthetic oil have done for me during all that time except
cost
a
lot of money?