i thought the auto manufacturers ran their motors for testing purposes before they even drop them into the car…
I have no idea - I’ve never bought a new car or blown a motor so I’ve never had to break anything in.
Guess I am just behind the times now 
I haven’t done anything special with the new car. I’m taking Carnut’s word for it. 
Verify oil pressure (shouldn’t be an issue with a new car) drive the hell out of it
I use the brick method… and then I take your car radio.
Well, If the motor get put in the miata.
Its breakin will be the trip to dunneville.
When I bought my Nissan Titan, the owners manual advised no towing for the first 500 miles. I was told it was due to all the problems they were having with the Dana 44 rear diff. I didn’t tow for about 600 miles & after 1,500 miles, I developed a rear diff pinion bearing noise. I took it in for warranty repair & they didn’t screw around, they replaced the entire rear diff from rotor to rotor. I now have 15,000 miles & still nice & quiet. Sucks that one of the only parts on my Nissan that was built by an American company fails. Anyhow, I did what was advised & I still had a problem.
that is how I broke in my last transmission except it was at TMP
i start the engine and look for leaks (talking rebuild here) and then hop in and take it easy till it hits warm and the ecu switches to the hot fuel and spark tables and then i hit it hard and let off against the engine. usually 15psi on my turbo stuff. drive around like this for 25-50 miles and then bring it home and change the oil and then again at 1000 and then the normal interval for a few changes on dino and then synthetic.
Brian
red line … all the time!
+1
if your going to quote joe, make sure you use a citation
seriously, who breaks in a car. you’re going to mod is anyways. i mean seriously.
i would either break it in right or not at all.
Since you have an STi I can tell you from testing of several new OEM STi engines that the rings seem to seat fully after 700-1400 miles depending on the car and how it’s driven. I’m basing this on several that we have done cylinder head leakdown tests on before installation, after 20 minute break in, and at multiple intervals during break in. I wouldn’t switch to synthetic until your leakdown has come down, which shows the rings are seating fully. That stock engine will go down to 0-3% when it’s broken in.
As far as how you drive it during that time, I wouldn’t wail on it until the rings have fully seated. Lots of engine braking should help speed things up. When I’m doing the initial tuning I drive around north Buffalo where there’s lots of stop signs and lights.
The STi engines we build up have all had 0-3% leakdown after the 20 minute break in alone. We change the oil and filter after that, drive the car for a bit to do the base tuning, change the oil and filter again, cut open that filter and inspect for assembly lube and/or metal/debris. If it’s clean we switch to synthetic and boost away. If not we drive it a little more and change the oil and filter again, then boost away (they’ve all been clean after that time). I feel the difference is based on the surface finish from the honing process because CP used to use stock rings with their pistons and when we used those it still broke in during that first 20 minutes.
The STI we delivered today got the 20 minute change and a 20 mile change and it’s good to go (filter was clean), but the owner is going to drive it on 11 psi for a week and then we’ll change the oil a third time and crank it up. Not a bad idea at all…
However you drive it, I suggest changing the oil a couple times right away. The new stock shortblocks always show metal in the oil filter the first couple times we change it so that’s all the reason I need.
I cannot speak for Subarus, but according to Honda, they say it usually takes around 8K miles to really break in the engine. As Mike said, it all depends on the honing but most cylinders are honed to break in slowly so they wear less over time and last longer. According to the engineers at Honda, there is “no recommended break-in period.” One guy told me to “drive it like I stole it” right off the lot. Keep in mind that Honda had no factory turbo cars at the time. I hope u enjoy your new STI. I have an 06 and love it. Its a blast and a tank in the snow.
Run it as hard as you ever plan to run it right out of the gate, if it cant handel it , it was not built properly.
Good job bumping this, im pretty sure the car is broken in by now :tup:
lol.