Whats the safest way to break in my engine? What rpm is the highest i should go before shifting?
Had the car a little over 24 hours and loving it more by the minute.

 

I shifted at around 3000 rpm.... and never over 4000rpm during my break in period. Not sure if that the right thing to do or not...
but thats what I did.

 

I'd say keep it under 4000 rpm for the first 600 miles, but also vary the engine speed as much as possible - avoid cruising on cruise control or maintaining steady speeds, even if it is annoying(!). Varying engine speed helps the piston rings bed in properly. Once the initial 600+ miles is done, don't suddenly start redlining it on every shift - take some more time until you extend the engine. After maybe 1200 miles the initial running in should be over. It'll probably be up to 6000 miles until the engine frees up nicely and all the parts get used to each other.

 

Vince,

try to change gears as often as conditions permit. Don't baby your car too much during this period.

That would be the best way to loosen up the gear box and the clutch, as well as to provide the necessary RPM changes to the engine.

Don't feel too bad if you rev it past 4000 rpm every now and then - sometimes you just have to in real world... The manual says - avoid flooring it, that's about it.

 

u should gradually ease it up the rpm up to 5000 miles. just to be safe and if u actually plan to keep it for a while, if not...oh well. should be home free after that.

 

Be gentle for the first 500 miles. Never drive at a constant rpm as it sets up wear patterns. An engine should be broken in over the ENTIRE rev band it is going to be run in on a regular basis. It you never go over 3000rpm for 2000 miles there will be a wear pattern established that will do more damage if you rev higher. There is no harm in reving the engine after the first 500 miles as long as you do not floor it for max output. You can rev to 6k smoothly with little pressure on the pedal and it does no harm. If you floor it the full power of the combustion blows by the unseated rings, valves, etc and does damage. I have made some great engines by just running up and down the rev band gently letting the engine get used to ALL speeds without setting up cylinder ridges at the point where the engine runs at 3k rpm. Remember that the pistons actually go a little bit further at higher rpm due to the stretch of the connecting rods. It is very, very small, but significant. The rings get compressed and leave gaps if the cylinder wall is not perfectly even.

 

The only problem with babying your engine too much is that you set up the potential for cylinder wall glazing. Low rpm driving does not expand the piston rings enough and the cylinder walls will be left with a coat of oil. High temperatures will then oxidize the oil film and glaze the walls which can only be corrected by rehoning the cylinder walls at considerable expense. Modern engines do not need excessive break-in like engines did years ago. Those that think they do are simply wrong.