Just returned from a 600+ mile trip with the new Sonata. It had just over
600 miles on it when I left and we put on another 630 or so. Fuel mileage
down was 27.0, on the return, 26.7. I'd expect to get even more if I
maintained a bit lower speed, but that is not bad with some driving at 80 -
85 mph, then 5 mph on the GS Parkway, then back to 75 - 80. .

I was very pleased with the way it handles at highway speed. Now that I
have some miles on it, I'll be able to try out some of the performance
characteristics. IMO, those first 2k or so miles with an easy break in help
with the longevity of the engine.
--
Ed
http://pages.cthome.net/edhome/

Edwin Pawlowski wrote:


Interestingly, I also believed that for many years, but now believe that
you should drive the engine from the start the way you plan to drive it
later. I came to this conclusion after looking at the break-in
procedures for airplane engines and also the general lack of break-in
procedures specified for most new cars - other than to avoid prolonged
operation at a constant RPM.


Matt

"Matt Whiting" <whiting@epix.net> wrote in message

Back in the 50's, break-in was a slow procedure. I'm sure with modern
lubricants and much better alloys, it is not such a big deal. While I do
drive "normally", I don't take the rpm up too high at first, "just in case",
if for no other reason. IIRC, years ago the first oil change was at 500
miles.

Edwin Pawlowski wrote:

What about high RPM do you think would cause harm?

Matt

"Matt Whiting" <whiting@epix.net> wrote in message

High rpm with tight fit = friction = more heat buildup.

Edwin Pawlowski wrote:

Yes, I certainly wouldn't run for hours at high RPM, but acclerating at
high RPM is actually helpful in breaking in a new engine. The higher
cylinder pressures push the compression rings against the cylinders
harder thus breaking things in before a layer of glaze can develop. I
ran my Sonata up to 6,000 RPM several times during break-in, but tend to
shift at 3,000 most times now.


Matt

On Wed, 04 Oct 2006 22:19:09 GMT, Matt Whiting <whiting@epix.net>
wrote:



You go Matt! Maybe NASCAR is in your future!

I think Ed is right on target, and so are you.

Manufacturers used to struggle just to maintain tolerances and nice
round bores using the clunky non-computerized machines of the day. To
produce anything close to today's precision engines probably would
have taken all day just to manufacture 1 engine.

There's a principle in wear surface break in which the bulk of it (and
most critical part) occurs in a very short time. Assuming all the
parts are properly lubed, the first 25 miles of running probably
accounts for 50% of the break in. Each successive 10% of break in
takes longer that the previous 10%.

A chart may look like this. Hypothetical of course, but it illustrates
the way break in works:

25 miles = 50% break in
100 miles = 75%
250 miles = 87%
750 miles = 95%
1500 miles = 97%
5000 miles = 99% (A question for the ages: do you ever get to 100%?)

A chart on an engine of the 1950's would probably show 2x the mileage
at each step.

No wonder modern engines don't use a quart of oil before the first
change, a they commonly did in the 1950's.

-

Bob

Bob Adkins wrote:


Actually, I've had a couple of auto engineers tell me that the greatest
reason for the reduction in oil use is the PCV system, not what gets
past the rings and value stems.

Matt

"Bob Adkins" <bobad@charter.net> wrote in message

I guess I'm at 98% now. Just got back from another trip and it erased and
doubts as to why I hate the NJ Turnpike. It is a good run for breaking it a
car because you do get brief stretches of 75 mph, followed by long periods
of 10 mph. On the NY Thruway though, I was able to cruise nicely at 80 to 85
and the car felt very solid and in control.

As for you question about 100%, I guess that is a brief moment on the bell
curve from breaking in to wearing out.

80 - 85 on the NYS Thruway will get you a very expensive ticket plus an
insurance surcharge that will make the speeding ticket look like the $2.00
it takes to ride the subway.

"Edwin Pawlowski" <esp@snet.net> wrote in message
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