I downloaded a owners manual for the dart and was somewhat surprised it recommends a break in of 300 miles. First 60 moderate speeds then there on out 55 or so with some full throttle in high gear spurts. I've never had to actually break a motor in so this will be a first. Should i highway cruise for 60 miles or so at 55-60 with some throttle blips and then after 60 miles can i go faster. Whats thee best way to do this?
dart actually has a break in period
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You should constantly vary your speed and not do a consistent
highway run. A nice back road with varied speeds and hills if you're lucky works great.
highway run. A nice back road with varied speeds and hills if you're lucky works great.
Run it to the redline as soon as the oil is warm! The engine doesnt need broken in.
Personally I would run it hard for those first 300 miles.
Personally I would run it hard for those first 300 miles.
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My 15 malibu i just bought had a break-in period of 500 miles. All it really says n the manuel is not 2 drive at constant speed 4 the first 500 miles. She's got 2k on her so far and doing good.
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I wonder why it always says "no constant speed"? Why is constant speed bad?
JHZR2
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Drive gently but varied and with some moderate (but not full) throttle instances from new.
WOT is not desirable, nor is being overly light with the pedal.
The key is that you want some time with different cylinder pressures and vacuum, but you dont want anything crazy or sustained, because you want to let the parts wear in to each other for a bit.
Its neither rocket science or something to ignore.
Plus a few heat-cool cycles is good to let everything feel some pressurization stress and then relax.
WOT is not desirable, nor is being overly light with the pedal.
The key is that you want some time with different cylinder pressures and vacuum, but you dont want anything crazy or sustained, because you want to let the parts wear in to each other for a bit.
Its neither rocket science or something to ignore.
Plus a few heat-cool cycles is good to let everything feel some pressurization stress and then relax.
JHZR2
Staff member
Originally Posted By: aquariuscsm
I wonder why it always says "no constant speed"? Why is constant speed bad?
Because while constant speed in the mountains can mean one thing, on the plains it can mean another. And neither are necessarily good. You want to allow as many ranges of pressure, temperature and other stresses, without being overly forceful or demanding on the powertrain while things temper and exercise into their places.
I wonder why it always says "no constant speed"? Why is constant speed bad?
Because while constant speed in the mountains can mean one thing, on the plains it can mean another. And neither are necessarily good. You want to allow as many ranges of pressure, temperature and other stresses, without being overly forceful or demanding on the powertrain while things temper and exercise into their places.
Originally Posted By: aquariuscsm
I wonder why it always says "no constant speed"? Why is constant speed bad?
A constant speed usually results in a constant torque (combustion charge) loading, resulting in the rings scraping the cylinder walls at about the same angle. Same angle means they could see a little extra wear on one area of the rings, which could then cascade into more ring twisting, wearing the rings into an odd shape. Vulnerable when new since machining cuts need to be ground down all over the rings shape, not just on one area.
In other words, one speed, one load, might create lopsided ring face shapes when they are vulnerable with new machining cuts, creating bad twisting action in their grooves and more lopsided wear. Potentially. This might happen. It usually does not.
I wonder why it always says "no constant speed"? Why is constant speed bad?
A constant speed usually results in a constant torque (combustion charge) loading, resulting in the rings scraping the cylinder walls at about the same angle. Same angle means they could see a little extra wear on one area of the rings, which could then cascade into more ring twisting, wearing the rings into an odd shape. Vulnerable when new since machining cuts need to be ground down all over the rings shape, not just on one area.
In other words, one speed, one load, might create lopsided ring face shapes when they are vulnerable with new machining cuts, creating bad twisting action in their grooves and more lopsided wear. Potentially. This might happen. It usually does not.
When the engine speed is varied the rings will seat a bit quicker because of the various loads and piston speeds experienced as they slide up and down the cylinders. The whole process is supposed to average out to long term relationship between the pistons, the rings and the cylinder walls. The tiny hot spots will be ironed out and your engine will live a long and happy life.
You're also breaking in the brakes, rear gears, trans etc on those first 500 miles.
Originally Posted By: dishdude
Interestingly enough, Chrysler has had this same exact verbiage in their owner's manuals since at least the 80's.
They have to be doing something right.
Interestingly enough, Chrysler has had this same exact verbiage in their owner's manuals since at least the 80's.
They have to be doing something right.
My Lexus manual says that breaking periods are optional. It says "While following these procedures may help to optimize engine performance and engine longevity over the life of the engine, these potential benefits are marginal compared to the benefits that result from ensuring that recommended maintenance is performed as scheduled." That sounds true to me.
I will state Honda said don't do constant speeds in my 95 Civic I purchased brand new. The first thing we did was put cruise on at 70MPH and drove cross country. 12 years later it did not burn a drop of oil nor have any engine issues at 240k miles when sold.
Originally Posted By: mrsilv04
So, did I miss some news? You finally pulled the trigger on a Dart?
Yes. Not sure if it's the one a dealer thought he bought or a new one.
I can't wait for all of the "problems" with this one!
So, did I miss some news? You finally pulled the trigger on a Dart?
Yes. Not sure if it's the one a dealer thought he bought or a new one.
I can't wait for all of the "problems" with this one!
Originally Posted By: Miller88
Originally Posted By: mrsilv04
So, did I miss some news? You finally pulled the trigger on a Dart?
Yes. Not sure if it's the one a dealer thought he bought or a new one.
I can't wait for all of the "problems" with this one!
Why would you wish trouble on someone ? Seems like an almost inhumane thing to do. If you have ever had a lemon believe me you wouldn't wish it on anyone.
Originally Posted By: mrsilv04
So, did I miss some news? You finally pulled the trigger on a Dart?
Yes. Not sure if it's the one a dealer thought he bought or a new one.
I can't wait for all of the "problems" with this one!
Why would you wish trouble on someone ? Seems like an almost inhumane thing to do. If you have ever had a lemon believe me you wouldn't wish it on anyone.
Originally Posted By: ram_man
Originally Posted By: Miller88
Originally Posted By: mrsilv04
So, did I miss some news? You finally pulled the trigger on a Dart?
Yes. Not sure if it's the one a dealer thought he bought or a new one.
I can't wait for all of the "problems" with this one!
Why would you wish trouble on someone ? Seems like an almost inhumane thing to do. If you have ever had a lemon believe me you wouldn't wish it on anyone.
I have had a lemon in the past. It completely turned me off from Cerberus Chrysler products. They did absolutely nothing for numerous electronic failures and a knocking engine with a lifetime warranty.
I'm surprised you were able to get something out of Ford for having a leaking timing cover gasket.
Originally Posted By: Miller88
Originally Posted By: mrsilv04
So, did I miss some news? You finally pulled the trigger on a Dart?
Yes. Not sure if it's the one a dealer thought he bought or a new one.
I can't wait for all of the "problems" with this one!
Why would you wish trouble on someone ? Seems like an almost inhumane thing to do. If you have ever had a lemon believe me you wouldn't wish it on anyone.
I have had a lemon in the past. It completely turned me off from Cerberus Chrysler products. They did absolutely nothing for numerous electronic failures and a knocking engine with a lifetime warranty.
I'm surprised you were able to get something out of Ford for having a leaking timing cover gasket.
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