The truths behind break-in periods

f350_or_bustf350_or_bust Member Posts: 13
I have a Ford F350 V10...etc., and was wondering
if anyone can shed some light on what happens
during the break-in period for this late model

Also, the owner's guide states to use a 5w-30 oil.
Since I live in San Antonio, can I use a 20w-50
oil instead? Either way, when should I go with
100% synthetic oil...and what weight should it be?

Any advice would be much appreciated.



  • quadrunner500quadrunner500 Member Posts: 2,721
    Rings mate to the cylinder walls, valves get seated, friction surfaces get burnished, gear faces mate,.....on and on....everything new....begins the process of getting old.

    Go easy on it...truck runs hotter at first. After it loosens up a bit, things calms down.

    You want parts to mate, break-in gradually, not under forced stresses of high load and rpm.

    20W50 is a very bad idea. You can go to 10W-30 in the hotter months.
  • modvptnlmodvptnl Member Posts: 1,352
    Like doctors opinions or engine builders choices or just about anything else in life if you ask 10 different people you'll get 10 different answers.

    Here's mine. I was a jet engine mechanic in the AF and have built countless motors from mild to wild. I have a Supercharged 502 in my boat(currently sans SC) '97 Cobra, Built a pretty healthy 5.0 EFI for my '69 Bronco project. The best way to "break in a motor" is to run it at ALL RPM's including redline for short bursts and to never let a motor drone at a constant speed for any length of time. On the freeway vary speeds and shift in and out of overdrive for approx. 1000 miles. I personally believe in changing oil at the first 1000 miles. Even though I run synthetics in my road going vehicles it has been proven that if you change your oil anally it can be considered a waste. The reason I use synthetics is I tend to punish my vehicles and it gives me a sense of security whether real or not. It gets to 120 degrees in Vegas and I occasionally shift at 7000 RPM's. In my boat I use regular oil because I run fresh water through the block with a GIANT heat exchanger and never get more then 140 degree engine temp and I change my oil twice a season which is like less then 20 hours between. I could get more power with higher operating temps but at the cost of longevity. Again these are just one person's opinion but I've used them for years and have never lost a motor.
  • modvptnlmodvptnl Member Posts: 1,352
    A Ford engineer told me to go no higher then 30 wt. on the Cobra due to small passages and tight clearances(OHC chain tensioners etc.) I'll go out on a limb because the V10 is related to the 4.6 and say the same rules apply. I run 5-30 Castrol Syntec BTW.
  • z71billz71bill Member Posts: 1,986
    No one in their right mind would run 20w50 oil in a new engine if the owners manual calls for 5w30.

    Some people think the heavy weight oils lubricate better or give you a boost in HP - that is plain BS. If in doubt use what your owners manual says.
  • redsilveradoredsilverado Member Posts: 1,000
    let 'em run 20w-50 i say. it'll be one less of
    those eyesores we have to look at. the onwners
    manual is just there in case you get bord right.

    ford engineer that recomends higher wt. oil is
    main reason fords don't last.
  • modvptnlmodvptnl Member Posts: 1,352
    Are you high? The Ford rep said, "Don't run the higher weight oil." Or maybe Chevy guys can't read.
  • redsilveradoredsilverado Member Posts: 1,000
    please except my humble apology.. but what the
    heck it's still a ford and god are they ugly.

    LURDBOY, are you following me?

    better stop it or i'll,i'll,i'll ..............








    what a LURD, you came all the down to see this.
  • redsilveradoredsilverado Member Posts: 1,000
    you've got me so nervous that i i i i'm stutt'
    stutt' stuttering. you you LURD. he he he
  • mgdvhmanmgdvhman Member Posts: 4,157
    that between you and me....You have always been the follower in life.(like a lost dog?..)...while I am the leader.

    (here boy..sit...good dog..)

    - Tim
  • RoclesRocles Member Posts: 982
    What the hell is a "lurd"??
  • mgdvhmanmgdvhman Member Posts: 4,157
    Translation for "Red"


    - Tim
  • cdeancdean Member Posts: 1,110
    Do NOT use 20w-50, ever! You will instantly void your warranty if you ever take it in and they prove you put 20W50 in the crankcase.

    I live in Austin, so I know your worries about the heat. really, these engines were designed in Detroit where it gets cold enough to need 10W and 5W oil, but around here, we only get a few days below 40. On my old truck, they recommended 5W30, but allowed 10w30 and straight 30 in high enough temps. I usually ran straight 30, because on the average Texas summer day, 10w30 looked like water. Now I have a '98, and the owners manual says nothing but 10W30 or 5W30--so 10W30 it is.

    follow the owners manual when it comes to oil!! For our weather, use the highest weight it allows, but nothing more.

    Engine break in--once again, the owners manual will tell you exactly what needs to be done.
    Who do you trust? us yahoo's around here that you don't know, or Ford Engineers? I'm willing to bet your owners manual says keep it at 55 and do no towing for the first 1000 miles.
  • redsilveradoredsilverado Member Posts: 1,000
    the ford guys can actually read.

    I'm astounded.

    TIM, i know what your trying to do.

  • modvptnlmodvptnl Member Posts: 1,352
    The last owners manual I read I believe said no break-in period is required. I'll try and dig it up to make sure. I also seem to remember no special first oil change requirement which this yahoo thinks is insane.
  • modvptnlmodvptnl Member Posts: 1,352
    Redturdarado "YOUR" a bafoon.
  • redsilveradoredsilverado Member Posts: 1,000
    relax guy i was just ribbin' you a bit. i totally

    agree on things you have said about break in.
    my dad was also in AF, he was crew chief on
    bombers then went into QC&E.
    we use to build and fly model pylon racers.
    learned alot about building engines and break-in.
    short duration motors were broke-in fast and
    furious while longevity motors were broke=in a
    little more on the conservative side.
    at any rate, if a new motor is babied too much it
    will more than likely be a weakling or oil
    sorry if i offended you.

  • towcrazy2towcrazy2 Member Posts: 337
    What can I say? I'm a Motor City guy who's been around the block as a supplier to the "big three" for nearly 20 years.

    My personal opinion, based on continued communication with factory techies who test vehicles in ALL environments, is that you can trust in the 10W-30 formulation.

    The 10W-40 formulation proved to be a dismal failure simply because it stretched multi-viscousity past its practical limit (for the time being). 20W-50 is GREAT... for use in my Harleys in the middle of the summer! But Harley tolerances are a far cry from the modern truck engine!

    Good luck to all!
  • modvptnlmodvptnl Member Posts: 1,352
    No offense taken. I just be ribbin' you right back.

    It does amaze me, though, when people attack intelligence, whether joking or not, that they'd leave themselves open with misspelled words and whatnot. You'd think one would be extra careful.
  • RoclesRocles Member Posts: 982
    Harley tolerances are a far cry from rudimentary engines......LOL! I know-I have a 93 FXR. However, my Honda Magna, with it's 45 cubic inch, 90 degree four cylinder requires 10w40 for most weather applications. I find it hard to believe that Honda engineers would put such a poor-excuse for a viscosity oil in such a hot little motor. Let's see.....redline 10 grand?
    Water-cooled motorcycle engines do require break-in but regular intervals afterward........
  • jescopjescop Member Posts: 33
    Am I wrong by thinking 5w-30 oil is as good in hot temps as say a straight 30 weight?
    I don't understand why a person would use a straight 30 weight when a 5w-30 is available.
    I hear this alot and I believe a straight weight is slightly a little better in higher temps, but not at the cost of the lack of lubercation at engine start-up.
    Am I wrong? I feel a 5w-30 is at least close to high temp protection as a straight 30.
  • dekingkdekingk Member Posts: 44
    The main reason Honda specifies the heavier oil is because the engine shares the oil with the tranny. That is asking a lot of a motor oil because of the shearing that takes place inside a transmission. Harley doesn't have that problem because the lubes are seperate.
  • RoclesRocles Member Posts: 982
    You proved my point. It also explains why most guys who buy Harleys, and aren't yuppies or dummies, toss out the stock tranny and get either a rev-tech or Andrews.
    Keep in mind that the 10w40 is an all-weather/all-purpose oil. The jack-of-all-trades oil.....
  • cdeancdean Member Posts: 1,110

    5W-30 is 5W oil, that supposed to act like 30W at high temperatures.

    If you have ever seen hot 5W30 and hot 30W side by side, you would see they are NOT the same. I don't agree they are the same at high temps. the manufacturers won't tell you this though because they make it much easier on themselves by specifying an oil that can qualify for ALL regions. heard this from Allison dealer who deals with manufacturers quite a bit.

    when it gets really hot, 5W30 is just a 5W oil. how much do you trust the polymers?
  • jescopjescop Member Posts: 33
    It only makes sense there is a difference, since so many small engines specify 30w ...not 5w30.
    I would still worry about engine start up with a straight 30 weight, but I also live in Minnesota.
    We get some hot days but not like Texas. Our winters are more of a concern.(sometimes -25 below or worse)

  • 2drive2drive Member Posts: 90
    I used 10w40 oil year around in Minnesota for
    16 years and did 392,000 miles on an all-original 2.2L 4 cyl. before I retired it.
  • dekingkdekingk Member Posts: 44
    I just read the owners manual for my new 2001 Dodge Ram diesel, and was especially interested in finding out how many miles I should put on it before I towed my fifth wheel with it. I had read in some of the posts in Edmund's that you should wait as long as your first oil change.
    Surprise! Dodge says don't wait. The manual suggests it is the best way to break in the new truck. The Cummins is ready for it out of the box. I'll probably have 1000 miles on mine before I'm ready to go but now I don't worry about it.
  • cdeancdean Member Posts: 1,110
    Today's diesels come out of the factory already broken in on the dyno.
  • rrichfrrichf Member Posts: 211
    That's really interesting. I wonder why none of the big three mention that as a feature in their advertising or in dealership materials. Even just a little something like, "We broke in your motor correctly, so your don't have to worry about it." It seems that they're missing an opportunity.
  • jescopjescop Member Posts: 33
    There is not much recomended for break-in in any new car manual. Your best bet is to talk to the guys that service them.
    It is just good a precautionary procedure to take it easy on new engines. Everything is new, tight, and seating in for a good 5000 miles. This builds more heat, and contaminates the oil with bit of metal. This leads me to me to the fact that most mechanics will tell you to change your oil at 1000 miles. They may be trying to drum up work for themselves, but I doubt it.
    I pamper my new vehicles to the extreme for 500 miles. For the next 500 miles I pretty much do the same I did in the first 500 miles.
    I gradually work my driving up to normal after my 1000 mile oil change.
    Diesels may be different, but talk to the guys that rebuild them.

  • mgdvhmanmgdvhman Member Posts: 4,157
    has a Powerstroke Crew cab...he broke it in by towing 29 foot trailer from Michigan to Florida!

    It's a 95 and all has been fine so farr.

    - Tim
  • swobigswobig Member Posts: 634
    there meant to be used. You don't buy a riding mower and let it idle for 100 hours before you use it do you? No, you put it to work. Put it to work, if it breaks it's under warranty...
  • tpmiller1tpmiller1 Member Posts: 165
    state that one should "avoid sudden stops" as the brake system breaks in. So you opt for the crash during them first 100 miles or so?
  • mgdvhmanmgdvhman Member Posts: 4,157
    Within the first 500 miles...I had a few of those slam brake you said....what are you supposed to do?....hit the guy in front of you to avoid improper brake wear?

    I think they mean hard braking all the time...

    - Tim
  • dekingkdekingk Member Posts: 44
    It's interesting that I used to read that you should take it easy with new brakes. Now the Dodge manual tells me to make about ten hard stops to break them in. Has something changed?
  • bobsyveebobsyvee Member Posts: 63
    One of the best things to do during whatever break-in period you decide to use, is to put a few ounces of Marvel Mystery Oil at the first few gas fillups. This stuff has been around a long time, and it works.
  • obyoneobyone Member Posts: 7,841
    snake oil?
  • z71billz71bill Member Posts: 1,986
    This stuff works great. Plugs your fuel filter and gives your exhaust that cool "blue smoke" look everyone wants in a new truck.
  • towcrazy2towcrazy2 Member Posts: 337

    It's clear that you've been around engines for awhile, and appreciate the virtues of Marvel Mystery Oil in the gas during break-in. I've used the stuff in all cars, trucks and bikes during break-in for 28 years, and it's never failed to produce a smooth-running and oil-tight motor after the break-in period.

    As I took automotive technology courses in college, I can't forget the instructor cautioning us to dump the stuff into the gas tank on EITHER a new or rebuilt motor. The principle is as simple as air... Reduce upper-cylinder wear during break-in, and you'll have a tighter, more durable engine in the longrun.

    As to the clogged fuel filters or blue smoke, I've not yet experienced either in using MMO in at least 15 vehicles, though I won't discount the possibility. What I CAN say I've experienced upon cylinder compression checks over the years is that all cylinders have checked out at high pressure, and with a maximum 10-15 PSI variance.

    Any comments?
  • modvptnlmodvptnl Member Posts: 1,352
    how everyone has their own theorys. A lot of people claim it's WRONG to use synthetics during break in because of LACK OF WEAR and the inability for the rings to seat properly. I'm not included in that thinking.

    Now with this mystery oil some one is saying because of the reduced wear you'll have a tighter cylinder seal.

    I still stand by an engine must be run at all speeds during break in for short durations and it must be exposed to various heat cycles to insure a long high performance life. Much like muscles, if only exposed to limited extensions when asked to go beyond those the performance suffers. I also stand by the first oil change at 1000 miles.
  • towcrazy2towcrazy2 Member Posts: 337
    Couldn't agree with you more on at least two counts... varying speeds during break-in is essential, and that oil change at 1,000 miles is also a practice of mine!

    Using a bit of MMO in the first couple tankfuls of gas simply serves to provide additional lubrication to the upper cylinders/valve seat area during the typically high-heat conditions that exist during say the first 500 miles on break-in.

    Interesting, too, is that different engines prefer different break-in periods. For example, the DC 5.9 V8 generally requires a good 1K miles to wear-in properly while the 4.7 V8 is generally good after just 500 miles... Of course, you're not going to find that info in the owner's manual... But it's something that the engineers who do the dyno-testing/tear-downs and experienced techs willingly volunteer!

    Suffice to say that it's wise to exercise the engine at different speeds with restraint over those first several hundred miles... In much the same way that you carefully stretch the muscles and warm up before a 10K run.
  • redsilveradoredsilverado Member Posts: 1,000
    on the break in and use of MMO as towcrazy
    outlines. finally someone who knows what he's
    talking about. MODVTPNL has'nt got a clue. i mean
    really, comparing muscles to a mechanical
    machine. ha ha ha while muscles have elasticity,
    how do you even relate that to something made of
    metal. does it stretch? err i don't think so. as
    for running engines at the rpm's like modvtpnl
    describes, well lets just say it's ok if your
    prepping a motor for racing. varying speeds in
    the range that one is going to operate the
    vehicle is more appropriate. if the engine is
    properly fit and assembled it will perform fine
    providing it's not lugged to death in the first
    few miles.

    on the subject of MMO, we use it in bearings that
    run in the 20,000 rpm and above range and it
    has'nt failed yet. it sure is'nt going to do any
    harm to a new engine.
  • f350_or_bustf350_or_bust Member Posts: 13
    Coming up on my first 3K miles in my 00' Ford F350 V10.

    I know there is a lot of "huppla" out there when there is discussion on when to change the oil the first time etc...But when is the best time to switch the oil to synthetic?

    Also, any suggestions on "name brand" synthetics would much be appreciated.

    I live in San Antonio, Texas so I plan on using 10w-30w...if someone thinks I should be using another weight, please let me know.

  • RoclesRocles Member Posts: 982
    I always thought that the Marvel oil is best on old engines.
  • obyoneobyone Member Posts: 7,841
    that old STP oil treatment?
  • modvptnlmodvptnl Member Posts: 1,352
    Metal absolutely expands and contracts, you moron. This is why you don't sustain high RPM's for any length of time on a green engine. If you had a clue you'd be dangerous, even the Chevy guys think you're an idiot.
  • modvptnlmodvptnl Member Posts: 1,352
    are set up with much looser clearances to begin with and break in is less important.
  • redsilveradoredsilverado Member Posts: 1,000
    sure metal expands and contracts but, it does'nt
    move around like a muscle. as far as how the
    chevy guys think about me is irrelavent as to
    what's being said between you and i. why do you
    resort to name calling? much less use the "chevy
    guys" to back up your opinion of me. you're
    obviously very immature or you would just say
    hmmm, 'oh well that's reds opinion. but nooo you
    have to call someone high school names like you
    do. or say "you're not spelling good enough".
    grow up dude and face the fact that you don't
    know everything like you think you do. i mean
    really, you're acting like a punk.

  • cdeancdean Member Posts: 1,110
    adding a little engineering talk to the debate, i do say you are wrong on your comparison of machine to muscle. An engine does not 'learn' its performance by the way you drive it at first.

    The entire reason you have to break in an engine is because the metals are fairly soft, straight from whichever manufacturing process. But the engine is NOT DESIGNED to run with the materials in this soft state. they are designed to run in the 'stretched', harder condition that comes with long term use. This is why you have to take it easy on an engine when brand new. kinda like if you take soft copper or aluminum core wire and beat the hell out of it with a hammer. it gets much harder. Thats called work hardening. The steel in your engine does the same thing.

    The engine reacts to thermal inputs and load inputs totally different when brand new as compared to when broken in. Stress and Strains are totally different on a NEW engine because the metals haven't been work hardened. The elasticity at new is different, and not designed for.

    an engine at 10,000 miles has metal that has been heated and strained and is operating at the predicted condition. engines brand new are softer and will wear easily and strain easily. You should take it easy on new engines.

    The amount of miles needed for break in vary from engine to engine because of differences in material, manufacturing and metallurgy, and construction processes.
  • redsilveradoredsilverado Member Posts: 1,000
    here's a question for you. this term is referring

    to a particular piston/sleeve combination. it is
    also sometimes uesd in motorcycle racing engines.

    it' called A/BC. or just ABC. it refers to the
    metal combination used for the piston and sleeve.

    can you tell us what this is?
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