Shane Olguin

Hey guys!

I got rid of my 2007 Mustang V6 and just bought a 2010 GT. It's real nice, has a big hood scoop and the raised spoiler in the rear, I'll post pictures later. I am curious about the "true" break in procedures. I've been reading a few forums.. some say go real easy on it for the first 500 miles, others say push it hard, some say change oil after 1000 miles...

I'm not sure what to do. What's the real scoop on this? I'll be honest with you, I kinda did a whistle-stop tour with my car yesterday and I was pushing it a bit.. I didn't redline it once but I certainly stood on it a little. I didn't damage it did I? I'll certainly avoid doing that if it will hurt the car over the long run.

Also, I heard something about alternating speeds in 4th and 5th gear on the interstate? That's going to be a problem because my drive to work consists of a lot of freeway driving which I typically use cruise control for. Should I not be doing this?

Thanks guys!

cgm10gt

First off, I dont think you hurt your car by pushing it a bit. Not at all. There are some people who will really push their car to break it in.

Having said that, I too am wondering about break in procedure. I too have heard both stories. The manual says to just vary the speed for the first 500? miles. So, no cruise control. Also, if you go by the manuals procedure, then you are covered if something happens to go wrong with the motor or transmission during the break in period. If you run it hard during this time, well, I dont know, they may be able to see how the car was drivin, and then say that since you didnt follow the manuals guidelines to breaking in the car, then you are out of warranty. Don't know about this, would need someone to give their opinion.

There are some here who have said they just use the manuals procedure for break in. I hope some of them chime in here and let us know how their car is performing.

I was reading over on camaro5 forums and there are alot of people who are using the "push hard" method of break in. One guy said that it seemed like every time he did a hard run, the car felt faster and stronger than the previous time. They post a link to a website that states that running it hard during the break in period will ensure proper ring sealing.

Now, I would assume that the manuals version of break in would be sufficient, however, I have also read, from people on the forums, that those manuals are basically written by lawyers and are written for the purpose of saving warranty claims, so I dont know. It may just be a protection thing is why they say to take it easy on the car.

The one thing that both methods have in common are to not stay at any constant speed for very long. Vary your speed. I think the idea, in both cases, is that they want you to vary the engine load.

Now, according to the camaro5 forums, if in fact the car gets stronger each time they did a hard run, then it would stand to prove the old saying "break it in like you plan to drive it", meaning, an easy break in will be fine if you plan to drive the car easy, and a hard break in will ensure proper ring seal and will give you more power later on.

Well, with all that written, I think I have successfully answered your post and have not actually answered your question....sorry

Dreamer1

LOL@ cgm10gt.. Yes but you covered the high points quite well..

Before I showed up here and started reading these said threads. The conversation about breaking the car in. I would have followed the manual and wanted to break her in easy.. But after reading and thinking about it. It seems logical for a hard break in. I'm probably going to break her in simi hard when I get my new ride..

My question now is. If I want to follow the logic of a hard break in. I would want to change my oil on the first five hundred miles to get rid of the small particulates from the new engine.. My question is, what non synthetic oil to go with? Something about glazing the inside of the cylinder. This and when do you start running synthetic oil??

Other then this I think I get the logic of what there saying. Hard versus factory suggestion of break in.. There are already a couple threads on the board going over this subject..(run a search.)

Course I'm more interested in the subject then others, as this will be my first new car. A new Mustang to boot... Always had used cars up till now..

Thanks for the reply's

Mark25

Slow and easy for the first 500 miles has been the tried and proven proper method...of course, it also depends how many miles were on your car when it was delivered and HOW was it driven during those miles...

I also change the oil/filter after the first 1000 miles (on a new car)...just an old habit and I think it's cheap insurance...

Norm Peterson

Don't forget that with a brand-new car you're breaking in more than just the engine. Axle gears in particular will generate huge amounts of heat during the first two or three hundred miles even if driven only mildly. Gear lube does have a limit to the temperature that it can withstand, and local overheating of gear teeth is not a good thing.

A hard break in may result in slightly more power earlier in the engine's life, but not without some risk. If your car is expected to be a "keeper", your goals are somewhat different from the guy who bought his first as a strip toy with daily-driver usage a secondary concern.


OP - you definitely need to keep varying your engine rpm. Part of your cooling is carried out by the oil, which splashes and flows differently at different rpms. There is some risk of local overheating if the oil flow is held back from the same area(s) for too long. More so at Interstate highway speeds, since you're generating more heat as it is. At least it isn't the worst of summer heat that you're doing this in, but you might want to go a bit easy on it for a while.

From time to time, my engineering profession has had me involved with thermal transient analyses (as in, what happens to the metal when you heat something up quickly), and I've built up street engines and installed axle gears that have lasted many miles. Just so you know that my basis is a bit wider than random "internet wisdom".


Norm

USAF in Germany

Whichever way you choose, I recommend changing the oil relatively early, say no more than the first 500 miles. There is a lot of metal particles coming off the bearing surfaces and cylinder walls that should be removed sooner than later. I also recommend buying a magnetic drain plug to install after your first oil change. Kind of like secondary protection to the oil filter for catching metal particles

Ken04

the manual says to break your car in in a way to benefit the manufacturer. Best way to break it in for power and longevity is to vary your engine speed as much as you can. Up and down thru the gears, sometimes driving like an old lady, sometimes like John Force. I have always broke in my cars fairly hard, not abusive, just hard, like I drive them. Best bet is to drive it like you will drive it every day in the future.

Shane Olguin

Thanks guys! I really appreciate the advice. I'll try not to go past 4000 on the tach, does that sound fair?

One thing I noticed is a lot of vibration in the gear shifter in 3rd gear when I'm coasting/no power on. Is this normal? Kinda feels like the syncronizers maybe?

cgm10gt

Thanks for the responses guys, that info helps me decide the way i'm going to break in my engine. And norm, you are right about the gears. I read something about when the rear end is being broken in, something about the wear pattern the gears will make depending on how you drive it. Something like if you break it in hard, you'll have a more narrow wear pattern on the teeth, and I guess that isnt a good thing.

At any rate, i'll probably break mine in per manual instructions, with an occasional "spritely" acceleration here and there.

Shane Olguin

Unfortunately you'll find that the occasional spritely acceleration is hard to control.. you tell yourself you'll only do it once and you end up driving the entire session that way. I'm at 250 miles right now and I've redlined a couple times now. It's reallllllly hard for me to do this break-in period!