I will receive my car on Friday and have a trip scheduled for that day(only a couple hundred miles). I've heard that with a new car you should vary the speeds(rpm) throughout long trips. Is this true?
David
I was doing a webex with one computer and surfering with the other. I should have searched the database. I found some posts that I THINK answered my question.
Yes
See the FAQ
http://www.planet-9.com/faq.php?faq=cayman#faq_caygen
There are many, many threads on this but the bottom line is you should read and observe what your manual says to do in break-in.
David - The short answer is, yes... several of the PCA tech experts have told me you should vary the RPMs as much as you can... definitely don't see how the cruise control works... use both your gas pedal and shift between 5th and 6th to vary the revs... see if you can find some backroads where you can vary them more naturally - it's good to have the RPMs vary while under load, rather than just cruising down the highway, but varying the RPMs n the highway won't hurt the car either...
brad
It'll have to be 4th to 5th, its a base. But it does seem that the varying rpms are a must.
Thanks guys,
David
David, there is plenty of info out there all correct, except not much explanations. Without the why it is difficult to remember what is good and what is bad.
Here is what I discovered over a few years of googling.
Rule 1: never labor the engine. 1200RPM on 6th gear is a very bad thing. It causes straight parts to deform,
Why: If the engine can not develop torque it can not push the car efficiently resulting in uneven wear patterns on your cylinder walls. Instead of pistons moving up and down (in out), they will be forced unevenly against the cylinder walls.
Rule 2: stick to the maximum RPM the manual recommends.
Why: predominantly this to prevent the tight clearance items, such as journal bearings from overheating and burning.
Rule 3: Vary the RPM.
Why: to let the journals polish each other and create good wear patterns for all varying RPM ranges not just 1. This will also help to sit the rings and valves.
How: This will handle rule 1, 2 and 3:
After the engine is fully warmed up, take it to 3000RPM, keep it there for 10 seconds and coast down. After a few hundred miles of 3000 RPMs take it to 3500 RPM keep it there for 10 seconds and coast down. Repeat the process as many times as you can with 5 minutes of regular driving to cool down mating parts. Then a few hundred miles later take it to 4000 RPM, keep it there 10 seconds and coast down. Repeat the process as often as you can. As you can see, this approach results in varying RPMs. Note, after the breakin period is over then take it to 4500 RPM repeat the process, then 5000 RPM a few hundred miles later. Keep increasing the RPM by 500 per 300/miles until you regularly take it to Max RPM. I am not advocating unsafe driving or abusive driving but to keep the engine to perform at its top capacity, full range of RPMs needs exercised on regular basis.
Next we need to think about the rings: According to modern manufacturing technologies and cylinder honing techniques, some people suggest drive it like you stole it. While there is some truth to that, without knowing the reasons, you can cause more damage than good.
Gradually increasing to a higher RPM (increasing RPM in the same gear from 1000 to 3000 in 4-5 seconds) causes the rings to expand and press against the cylinder walls, piston rings cut the ridges created by the cylinder wall honing process (this is what you see in oil after an oil change following the breakin. This is effective for engine with less than 10 hrs of running time (first 100 miles or so).
Gradually coasting down while in the same gear, results in increased engine vaccuum causing oil to clear the debris off the cylinder walls and tight mating surfaces.
Rule 4: Final rule: Enjoy every minute of it.
Drove mine from dealer in Portland,Or to So California (1100 miles) last year in the winter. Putted along the freeway and enjoyed every mile. Never realized before how nice heated seats are on a long drive with snow along the hillsides. Other then a tire balance problem the car has been absolutely trouble free. total 10,000 miles now.
