Here are some great info regarding Drivetrain Break-in, I got permission from the author (pelotonracer2) to share it here.
===========================================================
Engine and powertrain Break-in 101
1. Introduction:
-----------------
Every engine and powertrain is the sum of its' total parts. If those individual parts do not fit together properly (proper
bedding in), or the machined "finish" of those parts after being "run-in" are not optimal, both fuel mileage and
performance will suffer. Even though modern manufacturing processes have improved overall quality drastically over the
last several decades, performing a proper break-in procedure will ensure that your automobile will last longer, provide
better performance and return better efficiency (mpg) over the service life of the vehicle. Not all parts are created
equal, so some luck is also needed to get a good vehicle in the first place. A proper break-in just ensures you get the
most potential out of what you have. That is why even if you take 5-6 of the same car, one or two will always perform
better, get better mileage or last longer than the others. A good "break-in" usually equates to having an above average
car when it comes to performance, efficiency and longevity.
2. The "enemy"
----------------
The #1 enemy of an automobile "powertrain" (wear and tear) is heat and cold "extremes". Proper break-in of a modern
gasoline vehicle requires many heating and cool down "cycles" before it will deliever maximum performance and
efficiency. Heat in an engine is a by-product of friction and combustion. Most people, even driving enthusiasts do not
realize that 90% of engine (and powertrain) "wear" happens at engine start up and during the warm up cycle. The colder it
is outside, the more extreme and accelerated this "wear and tear" is. The goal to minimizing this (bad) wear, is to get
your engine fully warmed up in the quickest way possible AND to minimize the number of cold starts during a "cycle". It is
important to note that an engine and other powertrain components are usually made out of different types of metals,
including alloys. All respond to heat and friction differently, and all have shown to have different bedding-in qualities.
For instance, steel and iron is much more durable and more resistant to friction wear than say aluminum or other alloys.
It is even MORE important during engine break-in to minimize cold engine start ups and idling. The absolute worst driving
habit a new car owner can do is start their engine and just let it sit there at idle speed. Idling puts no load on the
engine, provides minimal lubrication on moving parts and takes much longer for the engine to warm up. As metal warms up,
it tends to change shape. In fact, some engine parts are designed to change their overall shape when they get to normal
operating temps (some pistons, with oval sideskirts are a perfect example... as the piston heats up, the sideskirts go
from oval to round). Idling also wastes fuel. The only exception to the "no idle" rule is on days where outside temps are
0 degrees or less. Then it is actually beneficial to start the engine and let it idle for 10 seconds. However, the best
driving procedure for extremely cold days (especially during the break-in) is not to drive the car at all.
The #2 enemy of your engine/powertrain is short trips of 10 miles or less. This is especially true on... you guessed it,
"cold days". If you have a second car (that is preferably well broken-in) it would be highly beneficial to take that
vehicle instead of your new car if you need to just drive down the street and back. Just because your coolant gauge reads
that the car has warmed up to normal operating temps after 2 miles or so, this does not mean all your moving parts are at
optimal operating temps. If you drive your car for 5 minutes and then shut it off, then do the same procedure a few times,
your engine and other vital parts never properly warm up and it's like adding 200 miles of bad wear to your car, even
though you may have only driven 10 miles total during your 5 stops.The #3 enemy of your new vehicle is lugging the motor. The #4 enemy of your engine/powertrain is improper driving techniques.
Recommended cold vehicle start up procedures:
a). Open the door of your car and get in. (duh!)
b). Put your seat belt on and make any adjustments in driving postion, mirrors or plug in your iPod BEFORE starting your
vehicle.
c). Start your engine and slowly drive away imediately. Pay special attention to rpm. Keep revs low, but DO NOT lug the
engine. If you can, during as much of the break-in as possible, leave the air conditioning turned OFF.
d.) Try to keep sustained rpm under 2750 rpm until engine is completely warm. For the first 250-300 miles of your break-in, never exceed 3000 rpm (cruising engine speed). I'm not saying don't use brief accelerations above this limit, just don't drive sustained engine speeds higher than this.
e.) Vary your engine speed AND road speeds. This creates different engine loads, different pressures and different friction values on the sum of your parts as they try to find a way to fit together and find conformity. It also changes the metal shearing process and provides more
even wear-in.
As I stated earlier, 90% of bad engine wear occurs at engine start up. But did you know that about 70% of your break-in
occurs in the first 100 miles? Look at it this way, if you will: The break-in of your new vehicle is nothing more than
removing enough material so that all the parts fit together (parts conformity) so that once the break-in is completed, you
have proper tolerances, fit and finish for optimal performance, efficiency and longevity.
3. The wear time line:
----------------------------
Since 70% or more of your new car break-in is achieved in the first 100 miles, logic dictates that this would be best
achieved in 2-3 driving events v.s. 10-12 driving events. That is because beneficial wearing-in happens while the engine
is running and completely warmed up, versus an engine that goes through the warm-up/cool down cycle a few times in the
same period of time. As an engine (and other drivetrain components) wear-in, the amount of material removed via friction
declines dramatically. The actual SIZE of those metal particles also reduce in physical size also, the more miles you put
on those components. So with that said (and this will sound CRAZY to most people), the best time to change your oil is
between 80-100 miles. I will repeat that, just in case you think you mis-read it. Change your oil after the first 80-100
miles! Why you ask? Well, firstly, your oil filter can only catch so many metal particles and your oil can only suspend so
many particles. Accelerated engine wear during break-in means more miniscule metal particles floating around your engine
just waiting to be squashed or redeposited on other moving parts. This is probably one of the BEST break-in tips I can
give. Change your oil and get the metal particles (the result of your engine parts rubbing against each other) out of your new engine! Having metal particles redistributed onto moving parts can often cause tolerance issues and lends to accelerated wear, increases friction and reduces efficiency. I HIGHLY recommend 4-6 ounces of Marvel Mystery Oil in your FIRST tank of gas ONLY. This aids in top cylinder lubrication and seating your rings. It also protects your cyclinder bore. I would recommend using the same oil brand, type and viscosity as what originally came with your car. Some people will argue (incorrectly) that manufacturers use a special break-in oil or add friction modifiers to their new engines. They used to do this practice many decades ago, but not today. DO NOT use synthetic oil at this time UNLESS your car came with sythetic or synthetic blend to start with. Even though 80-90% of your ring seating is achieved after only 30 minutes of continual driving, sythetic oils (or anything that reduces friction for that matter) will impede ring wear and cylinder bore wear during that last 10-20% of your seat process. Cylinder bores usually have a cross hatch machining process (or grooves) that aids in piston ring seating and oil retention. It is that last 10% of the machining process (of your rings
being pushed out onto the bore from compression) that gives you even better power, better efficiency and MUCH better
longevity. It's best to wait until you have around 7000-8000 miles on an engine before using a full synthetic. After the
first oil change at 100 miles has been completed, you can try some of the new driving techniques stated below.
After another 500-600 miles, you can... or should I say SHOULD change the oil again. Oil analysis shows that typical
engine machining (running in) has diminished noticeably and that the size of metal particles in the oil have also reduced
in size. You still want to get rid of those particles, because as they get smaller, more of them escape the oil filter
"catch" and tend to redeposit on moving parts. They are still a bit too big to stay completely suspended in the engine oil
for longer periods of time. If you decide to skip the 500-600 mile oil change, it is imparitive that you do your second
oil change no later than at the 1000 mile mark. Then your next oil change should be at 3000 miles, and then every 3000-
5000 miles (or whatever your owners manual recommends).
4. Driving Techniques:
---------------------
The owners manual is very vague concerning driving techniques and habits during the break-in period. The break-in period
driving techniques I will recommend will be broken down into 4 different stages. Each stage is used during a certain part
of the break-in distiguish by a mileage "scale".
Stage 1: Initial break-in period (0-100 miles)
This is probably the most important time for proper break-in procedures to be used because 80-90% of your break-in is
completed during this time.
Warm the car up fully. Vary engine speed (rpm) AND road speeds. Never exceed 3200 rpm at this stage (Fiesta ST specific). It is best to shift at or below 2500 rpm when the engine is cold, but avoid lugging the engine (using a gear that allows too low engine revolutions). Vary your driving. Do not do all of your driving on the highway or on city streets, mix it up every 15-20 minutes for the first 100 miles IF it is practical. Try to avoid high traffic areas, especially stop and go traffic conditions which is hard on new brakes, clutch linings and transmissions. To do a proper break-in, it is important to drive the car smoothly in each gear, being mostly gentle with throttle (this keeps drivetrain "lash" to a minimum). Vary the rpms in each gear. To help break-in your transmission, this means finding a place where you can drive in 1st and 2nd gear for a few minutes at a time. Remember, drive at different road speeds AND different engine speeds. Keep revs above 1800 rpm and below 3000 rpm.
For instance, once the car is fully warmed up start out in 2nd gear at about 2000 rpm. Hold that engine speed and road
speed for 15-20 seconds, then gently accelerate to 2250 rpm. Hold that engine and road speed for 15-20 seconds, then
gently accelerate to 2500 rpm. Hold for 10 seconds. Then.. gently lift the throttle and wait for rpm to drop to 1800 rpm
(coasting helps raise oil pressure and improves top cylinder lubrication), hold 1800 rpm for 15-20 seconds, then repeat
for 2000 rpm, 2250 rpm and then 10 seconds @ 2500 rpm. Then repeat the driving technique @ 1900 rpm, 2100 rpm, 2300 rpm
and 2500 rpm. Do this in each gear. Make sure road speeds are high enough that you are not lugging the engine. I would also recommend very brief full throttle accelerations in in a higher gear (preferably 4th or 5th gears, starting at around 2000 rpm. Gently ease into the throttle until you are at WOT count to 4 and then gently ease off the throttle, letting the engine coat back down to your original 2000 rpm starting point. This helps to seat the rings and provides additional upper cylinder lubrication where it is desperately needed at this point in the break-in.
Stage 2: Secondary break-in period (100-500 miles)
Warm up the car fully. Continue to vary engine speed AND road speeds as in Stage 1. Never exceed 3200 rpm (sustained engine speed) at this stage. It is still best to shift at or below 2500 rpm when the engine is COLD, and avoid lugging the engine (using a gear that allows too low engine revolutions causing the engine to kick or buck). Be sure to vary your driving habitat. Do not do all of your driving on the highway or on city streets, mix it up every 30-45 minutes. Still try to avoid traffic areas, especially stop and go traffic conditions which is hard on new brakes, clutch linings and transmissions/differentials. To do a proper break-in, it is still important to drive the car smoothly in each gear, being mostly gentle with throttle (this keeps drivetrain lashing to a minimum) but using brief (no more than 3-4 seconds) 50%-75% throttle position. WOT
(wide open throttle is 100% open). Continue to vary the rpms in each gear. To help break-in your transmission, this means
finding a place where you can drive in 1st and 2nd gear for a few minutes at a time. Remember, drive at different road
speeds AND different engine speeds, even in the lower gears. Keep revs above 1800 rpm and below 3500 rpm.
For instance, once the car is fully warmed up start out in 2nd gear at about 2000 rpm. Hold that engine speed and road
speed for 30 seconds, then gently accelerate to 2250 rpm. Hold that engine and road speed for 30 seconds, then gently
accelerate to 2500 rpm. Hold for 30 seconds. Then.. gently lift the throttle and wait for rpm to drop to 1800 rpm, hold
1800 rpm for 15-20 seconds, then repeat for 2000 rpm, 2250 rpm and then 10 seconds @ 2500 rpm. Then repeat the driving
technique @ 1900 rpm, 2100 rpm, 2300 rpm and 2500 rpm. Do this in each gear. Make sure road speeds are high enough that
you are not lugging the engine and creating too much load. You can now hold engine rpm and road speeds for longer periods of time. Once or twice per session after following the above procedures, set road speed at 40-45 mph and use 4th gear. Gently ease into the throttle until you are at 100% WOT. Hold for 6-7 seconds, then GENTLY ease off the throttle until your foot is no longer pressing on the pedal and let the engine coast back down to 1800 rpm. Do NOT exceed amount of time @ WOT and DO NOT use a gear bigger or smaller than 4th
gear at this time.
Stage 3: Pre final touch break-in period (500-1000 miles)
Continue to follow stage 2 recommendations. You can now hold road speeds and engine speeds up to 1-2 minutes at a time.
You can now also "safely" be more liberal or aggressive with throttle input and hold the high gear WOT technique to up to
10-12 seconds AND you can repeat this technique up to 8-10 times back to back (acceleration and coast down). Remember to still gently ease into the throttle and let off the pedal gently for coast down which aids in lubricating top area of cylinder. You can also be a bit more aggressive in 2nd and 3rd gears as well but you will STILL want to avoid WOT acceleration in 1st gear!!!
Stage 4: Going the extra mile(s) (1000-1500 miles)
You can pretty much drive the car as you want, but I still recommend following stage 2-3 driving techniques modestly, but
now you can hold speeds up to 5 minutes at each road speed/engine speed (except in the lower gears). The longer you extend
the break-in period (and not start ragging on your car), the more efficient and the longer it will last over the lefetime
of the vehicle. I recommend at least 1500 miles before taking your car to the track OR hooking it up to a chassis dyno. I'll wait until my Fiesta ST has 2500 miles and then I will get some baseline numbers from a chassis dyno. Your engine will most likely not make full power until you hit around 5000 miles anyways. Sometime between 1000-1500 miles is also a great time to change out your oil and transmission fluids. Keep in mind, there are moving parts in the transmission that also mesh together. Changing transmission fluid at this time gets rid of metal particles from the shearing process of your break-in and keeps them from being redeposited onto moving parts (which makes them less efficient, causing more power robbing friction, and less fuel economy). Remember, you are not just breaking in your powertrain. There are
other load bearing parts on a car that need to be properly broken in. This includes your brake pads, wheel bearings,
suspension parts, oil pump, water pump.. even your air conditioning.
So in the end, is it really worth all this extra effort during the break-in? I don't know. You be the judge. It really
boils down to what you intend to do with the car and how long you plan to keep it. However, I can tell you that in my 20+
years of mechanical engineering experience (I built and and tore down literally HUNDREDS of engines during testing and
design), and after building blue-printed parts bin, hand built engines for racing... after buying 47 new cars since 1986
and applying these methods, I'd have to say yes. My vehicles usually made more power at the wheels (stock or modified) on
the dyno than other like models with the same or no mods, have been quicker at the track and have higher trap speeds than
other same make and models, not to mention being able to achieve significantly higher than EPA mpg averages (when trying)
than the manufacturer states. Not to mention, out of 47 cars, and well over 1,000,000 miles driven, I've only had ONE mechanical problem (and that was due to the design and manufacturing) not the way the vehicle was being driven or maintained. I know this because this particular engine used oil since it was new, which only got worse over time until a bearing seized and destroyed the motor @ 58,000 miles. One brand new short block and 3000 miles later, the new one was doing the same thing (using way more oil than it should have been). Burning oil usually (but not always) is the result of a bad bore, piston ring or irregular piston/piston skirt wear. This was a '05 G35 3.5L engine (the same one used in the Nissan 350Z). No excuse for an engine with over 3000 miles to be burning oil especially if it was broken-in right. Come to find out later, based on forum exchanges with other owners, this was a pretty common issue. Not sure about the new(er) 3.7L G motor, but the 3.5L definately had lubrication issues.
Anyways, the above statements are just my personal experiences and opinion. I tried to make this information as simple to undstand as possible so that even a small child could comprehend the information. lol. I also apologize if this comes out not looking right. I wrote in on notepad in about an hour.![[8]](/images/smilies/icon_smile_8ball.gif "Retarded [8]")
===========================================================
Engine and powertrain Break-in 101
1. Introduction:
-----------------
Every engine and powertrain is the sum of its' total parts. If those individual parts do not fit together properly (proper
bedding in), or the machined "finish" of those parts after being "run-in" are not optimal, both fuel mileage and
performance will suffer. Even though modern manufacturing processes have improved overall quality drastically over the
last several decades, performing a proper break-in procedure will ensure that your automobile will last longer, provide
better performance and return better efficiency (mpg) over the service life of the vehicle. Not all parts are created
equal, so some luck is also needed to get a good vehicle in the first place. A proper break-in just ensures you get the
most potential out of what you have. That is why even if you take 5-6 of the same car, one or two will always perform
better, get better mileage or last longer than the others. A good "break-in" usually equates to having an above average
car when it comes to performance, efficiency and longevity.
2. The "enemy"
----------------
The #1 enemy of an automobile "powertrain" (wear and tear) is heat and cold "extremes". Proper break-in of a modern
gasoline vehicle requires many heating and cool down "cycles" before it will deliever maximum performance and
efficiency. Heat in an engine is a by-product of friction and combustion. Most people, even driving enthusiasts do not
realize that 90% of engine (and powertrain) "wear" happens at engine start up and during the warm up cycle. The colder it
is outside, the more extreme and accelerated this "wear and tear" is. The goal to minimizing this (bad) wear, is to get
your engine fully warmed up in the quickest way possible AND to minimize the number of cold starts during a "cycle". It is
important to note that an engine and other powertrain components are usually made out of different types of metals,
including alloys. All respond to heat and friction differently, and all have shown to have different bedding-in qualities.
For instance, steel and iron is much more durable and more resistant to friction wear than say aluminum or other alloys.
It is even MORE important during engine break-in to minimize cold engine start ups and idling. The absolute worst driving
habit a new car owner can do is start their engine and just let it sit there at idle speed. Idling puts no load on the
engine, provides minimal lubrication on moving parts and takes much longer for the engine to warm up. As metal warms up,
it tends to change shape. In fact, some engine parts are designed to change their overall shape when they get to normal
operating temps (some pistons, with oval sideskirts are a perfect example... as the piston heats up, the sideskirts go
from oval to round). Idling also wastes fuel. The only exception to the "no idle" rule is on days where outside temps are
0 degrees or less. Then it is actually beneficial to start the engine and let it idle for 10 seconds. However, the best
driving procedure for extremely cold days (especially during the break-in) is not to drive the car at all.
The #2 enemy of your engine/powertrain is short trips of 10 miles or less. This is especially true on... you guessed it,
"cold days". If you have a second car (that is preferably well broken-in) it would be highly beneficial to take that
vehicle instead of your new car if you need to just drive down the street and back. Just because your coolant gauge reads
that the car has warmed up to normal operating temps after 2 miles or so, this does not mean all your moving parts are at
optimal operating temps. If you drive your car for 5 minutes and then shut it off, then do the same procedure a few times,
your engine and other vital parts never properly warm up and it's like adding 200 miles of bad wear to your car, even
though you may have only driven 10 miles total during your 5 stops.The #3 enemy of your new vehicle is lugging the motor. The #4 enemy of your engine/powertrain is improper driving techniques.
Recommended cold vehicle start up procedures:
a). Open the door of your car and get in. (duh!)
b). Put your seat belt on and make any adjustments in driving postion, mirrors or plug in your iPod BEFORE starting your
vehicle.
c). Start your engine and slowly drive away imediately. Pay special attention to rpm. Keep revs low, but DO NOT lug the
engine. If you can, during as much of the break-in as possible, leave the air conditioning turned OFF.
d.) Try to keep sustained rpm under 2750 rpm until engine is completely warm. For the first 250-300 miles of your break-in, never exceed 3000 rpm (cruising engine speed). I'm not saying don't use brief accelerations above this limit, just don't drive sustained engine speeds higher than this.
e.) Vary your engine speed AND road speeds. This creates different engine loads, different pressures and different friction values on the sum of your parts as they try to find a way to fit together and find conformity. It also changes the metal shearing process and provides more
even wear-in.
As I stated earlier, 90% of bad engine wear occurs at engine start up. But did you know that about 70% of your break-in
occurs in the first 100 miles? Look at it this way, if you will: The break-in of your new vehicle is nothing more than
removing enough material so that all the parts fit together (parts conformity) so that once the break-in is completed, you
have proper tolerances, fit and finish for optimal performance, efficiency and longevity.
3. The wear time line:
----------------------------
Since 70% or more of your new car break-in is achieved in the first 100 miles, logic dictates that this would be best
achieved in 2-3 driving events v.s. 10-12 driving events. That is because beneficial wearing-in happens while the engine
is running and completely warmed up, versus an engine that goes through the warm-up/cool down cycle a few times in the
same period of time. As an engine (and other drivetrain components) wear-in, the amount of material removed via friction
declines dramatically. The actual SIZE of those metal particles also reduce in physical size also, the more miles you put
on those components. So with that said (and this will sound CRAZY to most people), the best time to change your oil is
between 80-100 miles. I will repeat that, just in case you think you mis-read it. Change your oil after the first 80-100
miles! Why you ask? Well, firstly, your oil filter can only catch so many metal particles and your oil can only suspend so
many particles. Accelerated engine wear during break-in means more miniscule metal particles floating around your engine
just waiting to be squashed or redeposited on other moving parts. This is probably one of the BEST break-in tips I can
give. Change your oil and get the metal particles (the result of your engine parts rubbing against each other) out of your new engine! Having metal particles redistributed onto moving parts can often cause tolerance issues and lends to accelerated wear, increases friction and reduces efficiency. I HIGHLY recommend 4-6 ounces of Marvel Mystery Oil in your FIRST tank of gas ONLY. This aids in top cylinder lubrication and seating your rings. It also protects your cyclinder bore. I would recommend using the same oil brand, type and viscosity as what originally came with your car. Some people will argue (incorrectly) that manufacturers use a special break-in oil or add friction modifiers to their new engines. They used to do this practice many decades ago, but not today. DO NOT use synthetic oil at this time UNLESS your car came with sythetic or synthetic blend to start with. Even though 80-90% of your ring seating is achieved after only 30 minutes of continual driving, sythetic oils (or anything that reduces friction for that matter) will impede ring wear and cylinder bore wear during that last 10-20% of your seat process. Cylinder bores usually have a cross hatch machining process (or grooves) that aids in piston ring seating and oil retention. It is that last 10% of the machining process (of your rings
being pushed out onto the bore from compression) that gives you even better power, better efficiency and MUCH better
longevity. It's best to wait until you have around 7000-8000 miles on an engine before using a full synthetic. After the
first oil change at 100 miles has been completed, you can try some of the new driving techniques stated below.
After another 500-600 miles, you can... or should I say SHOULD change the oil again. Oil analysis shows that typical
engine machining (running in) has diminished noticeably and that the size of metal particles in the oil have also reduced
in size. You still want to get rid of those particles, because as they get smaller, more of them escape the oil filter
"catch" and tend to redeposit on moving parts. They are still a bit too big to stay completely suspended in the engine oil
for longer periods of time. If you decide to skip the 500-600 mile oil change, it is imparitive that you do your second
oil change no later than at the 1000 mile mark. Then your next oil change should be at 3000 miles, and then every 3000-
5000 miles (or whatever your owners manual recommends).
4. Driving Techniques:
---------------------
The owners manual is very vague concerning driving techniques and habits during the break-in period. The break-in period
driving techniques I will recommend will be broken down into 4 different stages. Each stage is used during a certain part
of the break-in distiguish by a mileage "scale".
Stage 1: Initial break-in period (0-100 miles)
This is probably the most important time for proper break-in procedures to be used because 80-90% of your break-in is
completed during this time.
Warm the car up fully. Vary engine speed (rpm) AND road speeds. Never exceed 3200 rpm at this stage (Fiesta ST specific). It is best to shift at or below 2500 rpm when the engine is cold, but avoid lugging the engine (using a gear that allows too low engine revolutions). Vary your driving. Do not do all of your driving on the highway or on city streets, mix it up every 15-20 minutes for the first 100 miles IF it is practical. Try to avoid high traffic areas, especially stop and go traffic conditions which is hard on new brakes, clutch linings and transmissions. To do a proper break-in, it is important to drive the car smoothly in each gear, being mostly gentle with throttle (this keeps drivetrain "lash" to a minimum). Vary the rpms in each gear. To help break-in your transmission, this means finding a place where you can drive in 1st and 2nd gear for a few minutes at a time. Remember, drive at different road speeds AND different engine speeds. Keep revs above 1800 rpm and below 3000 rpm.
For instance, once the car is fully warmed up start out in 2nd gear at about 2000 rpm. Hold that engine speed and road
speed for 15-20 seconds, then gently accelerate to 2250 rpm. Hold that engine and road speed for 15-20 seconds, then
gently accelerate to 2500 rpm. Hold for 10 seconds. Then.. gently lift the throttle and wait for rpm to drop to 1800 rpm
(coasting helps raise oil pressure and improves top cylinder lubrication), hold 1800 rpm for 15-20 seconds, then repeat
for 2000 rpm, 2250 rpm and then 10 seconds @ 2500 rpm. Then repeat the driving technique @ 1900 rpm, 2100 rpm, 2300 rpm
and 2500 rpm. Do this in each gear. Make sure road speeds are high enough that you are not lugging the engine. I would also recommend very brief full throttle accelerations in in a higher gear (preferably 4th or 5th gears, starting at around 2000 rpm. Gently ease into the throttle until you are at WOT count to 4 and then gently ease off the throttle, letting the engine coat back down to your original 2000 rpm starting point. This helps to seat the rings and provides additional upper cylinder lubrication where it is desperately needed at this point in the break-in.
Stage 2: Secondary break-in period (100-500 miles)
Warm up the car fully. Continue to vary engine speed AND road speeds as in Stage 1. Never exceed 3200 rpm (sustained engine speed) at this stage. It is still best to shift at or below 2500 rpm when the engine is COLD, and avoid lugging the engine (using a gear that allows too low engine revolutions causing the engine to kick or buck). Be sure to vary your driving habitat. Do not do all of your driving on the highway or on city streets, mix it up every 30-45 minutes. Still try to avoid traffic areas, especially stop and go traffic conditions which is hard on new brakes, clutch linings and transmissions/differentials. To do a proper break-in, it is still important to drive the car smoothly in each gear, being mostly gentle with throttle (this keeps drivetrain lashing to a minimum) but using brief (no more than 3-4 seconds) 50%-75% throttle position. WOT
(wide open throttle is 100% open). Continue to vary the rpms in each gear. To help break-in your transmission, this means
finding a place where you can drive in 1st and 2nd gear for a few minutes at a time. Remember, drive at different road
speeds AND different engine speeds, even in the lower gears. Keep revs above 1800 rpm and below 3500 rpm.
For instance, once the car is fully warmed up start out in 2nd gear at about 2000 rpm. Hold that engine speed and road
speed for 30 seconds, then gently accelerate to 2250 rpm. Hold that engine and road speed for 30 seconds, then gently
accelerate to 2500 rpm. Hold for 30 seconds. Then.. gently lift the throttle and wait for rpm to drop to 1800 rpm, hold
1800 rpm for 15-20 seconds, then repeat for 2000 rpm, 2250 rpm and then 10 seconds @ 2500 rpm. Then repeat the driving
technique @ 1900 rpm, 2100 rpm, 2300 rpm and 2500 rpm. Do this in each gear. Make sure road speeds are high enough that
you are not lugging the engine and creating too much load. You can now hold engine rpm and road speeds for longer periods of time. Once or twice per session after following the above procedures, set road speed at 40-45 mph and use 4th gear. Gently ease into the throttle until you are at 100% WOT. Hold for 6-7 seconds, then GENTLY ease off the throttle until your foot is no longer pressing on the pedal and let the engine coast back down to 1800 rpm. Do NOT exceed amount of time @ WOT and DO NOT use a gear bigger or smaller than 4th
gear at this time.
Stage 3: Pre final touch break-in period (500-1000 miles)
Continue to follow stage 2 recommendations. You can now hold road speeds and engine speeds up to 1-2 minutes at a time.
You can now also "safely" be more liberal or aggressive with throttle input and hold the high gear WOT technique to up to
10-12 seconds AND you can repeat this technique up to 8-10 times back to back (acceleration and coast down). Remember to still gently ease into the throttle and let off the pedal gently for coast down which aids in lubricating top area of cylinder. You can also be a bit more aggressive in 2nd and 3rd gears as well but you will STILL want to avoid WOT acceleration in 1st gear!!!
Stage 4: Going the extra mile(s) (1000-1500 miles)
You can pretty much drive the car as you want, but I still recommend following stage 2-3 driving techniques modestly, but
now you can hold speeds up to 5 minutes at each road speed/engine speed (except in the lower gears). The longer you extend
the break-in period (and not start ragging on your car), the more efficient and the longer it will last over the lefetime
of the vehicle. I recommend at least 1500 miles before taking your car to the track OR hooking it up to a chassis dyno. I'll wait until my Fiesta ST has 2500 miles and then I will get some baseline numbers from a chassis dyno. Your engine will most likely not make full power until you hit around 5000 miles anyways. Sometime between 1000-1500 miles is also a great time to change out your oil and transmission fluids. Keep in mind, there are moving parts in the transmission that also mesh together. Changing transmission fluid at this time gets rid of metal particles from the shearing process of your break-in and keeps them from being redeposited onto moving parts (which makes them less efficient, causing more power robbing friction, and less fuel economy). Remember, you are not just breaking in your powertrain. There are
other load bearing parts on a car that need to be properly broken in. This includes your brake pads, wheel bearings,
suspension parts, oil pump, water pump.. even your air conditioning.
So in the end, is it really worth all this extra effort during the break-in? I don't know. You be the judge. It really
boils down to what you intend to do with the car and how long you plan to keep it. However, I can tell you that in my 20+
years of mechanical engineering experience (I built and and tore down literally HUNDREDS of engines during testing and
design), and after building blue-printed parts bin, hand built engines for racing... after buying 47 new cars since 1986
and applying these methods, I'd have to say yes. My vehicles usually made more power at the wheels (stock or modified) on
the dyno than other like models with the same or no mods, have been quicker at the track and have higher trap speeds than
other same make and models, not to mention being able to achieve significantly higher than EPA mpg averages (when trying)
than the manufacturer states. Not to mention, out of 47 cars, and well over 1,000,000 miles driven, I've only had ONE mechanical problem (and that was due to the design and manufacturing) not the way the vehicle was being driven or maintained. I know this because this particular engine used oil since it was new, which only got worse over time until a bearing seized and destroyed the motor @ 58,000 miles. One brand new short block and 3000 miles later, the new one was doing the same thing (using way more oil than it should have been). Burning oil usually (but not always) is the result of a bad bore, piston ring or irregular piston/piston skirt wear. This was a '05 G35 3.5L engine (the same one used in the Nissan 350Z). No excuse for an engine with over 3000 miles to be burning oil especially if it was broken-in right. Come to find out later, based on forum exchanges with other owners, this was a pretty common issue. Not sure about the new(er) 3.7L G motor, but the 3.5L definately had lubrication issues.
Anyways, the above statements are just my personal experiences and opinion. I tried to make this information as simple to undstand as possible so that even a small child could comprehend the information. lol. I also apologize if this comes out not looking right. I wrote in on notepad in about an hour.
