I have plenty of experience building and tearing down engines, specifically with ring gapping. I've seen what engines that followed manufacturers vs hard break in regimens look and how their rings and walls have worn in.
What experience do you have? Here's a clue for you. I have no financial stake in how long the OP's vehicle lasts. The manufacturer does. Their advice will thus be skewed.
Also, there's this guy, but I'm sure his experience is nothing either.
http://www.mototuneusa.com/break_in_secrets.htm
I've never broken in an engine in the way you describe and I've never had any oil consumption issues with any vehicle I've owned since new.
Here's a nice little bit of information on how Porsche assembles their engines and why they recommend breaking in the engine gradually.
http://yel.pca.org/porsche-engine-break-in/
By the way, some of the newer BMW motorcycles actually electronically limit you to certain RPMs during the break-in period. Gee, I wonder why that is...
OP, do you want to listen to a total stranger on the interwebs or the people who designed and built your car?
bought a new 2015 mazda3i automatic.
Whats the best way to break it in, if any?
The manufacturer already provided the info. Don't waste your time with internet forum nonsense with the same tired old link. Just read your manual.
BREAK-IN PERIOD
No special break-in is necessary,but a few precautions in the first 600 miles should be observed.
Do not race the engine.
Do not maintain one constant speed, either slow or fast, for a long period of time.
Avoid full-throttle starts.
Avoid unnecessary hard stops.
Do not drive constantly at full-throttle or high engine rpm for extended periods of time.
If you want to ignore your manual and drive it like the you stole it, then go ahead, It won't matter.
In the end, you are driving an appliance designed to last over the manufacturers estimated lifetime of the vehicle.
bought a new 2015 mazda3i automatic.
Whats the best way to break it in, if any?
Everyone I pretty much respect over the years have always said one thing: flog it and you'll be good but if you drive it like granny you'll have fun with oil consumption down the road earlier than later.
True? Beats me. I flog my stuff. No oil consumption problems. I don't mean redline your stuff, I mean like drive as if you want to get from Point A to Point B with a degree of enthusiasm if you know what I mean.
Is that pulled from the manual?
I call BS on that Porsche article. They run the engine up to near redline over a 30 min. dyno run, during which time the engine gets fully up to temperature, then they say to keep the rpm's down? Ridiculous.
Regarding motorcycles, the manufacturers warn owners to keep the rpm's down to keep said owner from wadding up the bike straight off the showroom floor. I suspect the Porsche instruction is focused on same.
I worked for a major Japanese OEM car manufacturer for 21 years and know a thing or two about such matters.
With modern engines the break in method is relatively unimportant. Main things are to vary the rpm and put some load on the rings. Redline is not recommended right away and no lugging. That's about it. By the time the engine has run through a tank of fuel you can just use the vehicle normally.
Edit: just checking back on that Porsche article and found the following quote:
"Many experienced Porsche engine builders and experts on the Flat-6 engine state that the peak power of a Porsche engine is developed around the 20,000 mile mark."
Anyone believing this should have their head examined.
i would just drive the car normally as this is how the car will likely be driven over its life. As has been said avoid over revving the motor and excessive speed for the first 1000 miles. Possibly changing the oil and filter after the break in period will help also.
I am very amused at the internet experts here who think they know better than the designers of the vehicle, but can't be arsed to think about drive-train components that aren't the engine that are also heavily affected by break-in procedures.
Put it in neutral, floor the gas, and keep the engine at 6500 rpm for 5 minutes immediately after starting the engine on a cold winter day
I call BS on that Porsche article. They run the engine up to near redline over a 30 min. dyno run, during which time the engine gets fully up to temperature, then they say to keep the rpm's down? Ridiculous.
Regarding motorcycles, the manufacturers warn owners to keep the rpm's down to keep said owner from wadding up the bike straight off the showroom floor. I suspect the Porsche instruction is focused on same.
I worked for a major Japanese OEM car manufacturer for 21 years and know a thing or two about such matters.
With modern engines the break in method is relatively unimportant. Main things are to vary the rpm and put some load on the rings. Redline is not recommended right away and no lugging. That's about it. By the time the engine has run through a tank of fuel you can just use the vehicle normally.
Edit: just checking back on that Porsche article and found the following quote:
"Many experienced Porsche engine builders and experts on the Flat-6 engine state that the peak power of a Porsche engine is developed around the 20,000 mile mark."
Anyone believing this should have their head examined.
I'm sure Chevrolet and Porsche are idiots though and don't know what the best procedure is for breaking in their high performance engines... it's not like they have decades of racing history and manufacturing behind them or anything. Maybe they just don't want their customers "wadding up the car as they roll off the dealer lot?"New Vehicle Break-In:
Follow these recommended guidelines during the first 2 414 km (1,500 mi) of driving this vehicle. Parts have a break-in period and performance will be better in the long run.
For the first 322 km (200 mi):
To break in new tires, drive at moderate speeds and avoid hard cornering.
New brake linings also need a break-in period. Avoid making hard stops. This is recommended every time brake linings are replaced.
For the first 800 km (500 mi):
Avoid full throttle starts and abrupt stops.
Do not exceed 4000 rpm.
Avoid driving at any one constant speed, fast or slow, including the use of cruise control.
Avoid downshifting to brake or slow the vehicle when the engine speed will exceed 4000 rpm.
Do not let the engine labor.
Never lug the engine. With a manual transmission, shift to the next lower gear. This rule applies at all times, not just during the break-in period.
After the first 800 km (500 mi), change the engine oil on vehicles with the LT1 engine and Z51 package, or the LT4 engine.
For the first 2 414 km (1,500 mi):
Do not participate in track events, sport driving schools, or similar activities.
Check engine oil with every refueling and add if necessary.
Oil and fuel consumption may be higher than normal.
I did other than one accidental instance of > 4,500 rpm for a few seconds (which won't matter being as it was just a second or two anyway)
No hard launches, no >4,500 rpm, varied speeds and rpms for 500 miles. No track events until 1,500 miles (or maybe it was 1,250). Oil change at 500 miles because chemicals released during curing from the seals in the dry sump system contaminates oil and causes frothing and thus oil in the intake.
For track, different oil weight, after first track event, diff fluid change.
Well, I could have done whatever since I sold it at 4,250 miles anyway...
can you give a reason why you think this is a good way to break in a car?
My fleet of rides I've driven are around a million miles and I've yet to have one use a noticeable amount of oil.
Granted, I do my own maintenance and take care of my stuff.
It's always possible the next million I'll have issues.
So far so good and I like my odds.
I'm curious, what car do you have with a million miles on it?
Coincidentally and equally anecdotally, a close friend of ours has over 500,000 miles on a 2002 Lexus ES300 on the original engine (she is the original owner). She is the most conservative driver I've ever met and I doubt that engine has ever been to redline and it doesn't consume oil or leak a drop.
I rode with her to Palm Springs once from San Diego and I swear we never exceeded 70mph the entire time nor did we ever accelerate at a brisk pace.
The manufacturer already provided the info. Don't waste your time with internet forum nonsense with the same tired old link. Just read your manual.
BREAK-IN PERIOD
No special break-in is necessary,but a few precautions in the first 600 miles should be observed.
Do not race the engine.
Do not maintain one constant speed, either slow or fast, for a long period of time.
Avoid full-throttle starts.
Avoid unnecessary hard stops.
Do not drive constantly at full-throttle or high engine rpm for extended periods of time.
If you want to ignore your manual and drive it like the you stole it, then go ahead, It won't matter.
In the end, you are driving an appliance designed to last over the manufacturers estimated lifetime of the vehicle.