Does anyone here feel it necessary to "Break In" a new Engine.
I don't
I don't
Engine Break-in
- Thread starter Al
- Start date
Yes
Factory? 'Field' overhaul that you did? Crate reman? Follow the OEM or builders advice...
Cons of not breaking in an new engine...
- Potentially poorer ring seal and slight increase in blow-by
- Potentially higher wear for first few hundred miles
Cons of breaking in a new engine...
- None
Many OEM engines are "run in" on a spintron which is really more of a functions check.
- Potentially poorer ring seal and slight increase in blow-by
- Potentially higher wear for first few hundred miles
Cons of breaking in a new engine...
- None
Many OEM engines are "run in" on a spintron which is really more of a functions check.
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We try to take it easy first 500 miles or so. Within reason.
I got my Mazda 3 with 4K on it, so God only knows how it was driven to start it's life......
I got my Mazda 3 with 4K on it, so God only knows how it was driven to start it's life......
Propflux01
$100 Site Donor 2025
Varying speed, accelerator up to full throttle but at lower top RPM (Ex: 1500 to 35-4000 Max), foot off accelerator going downhill, allowing full vacuum, Easy throttle during engine cold. Normal highway speeds. That method has worked for me for decades.
You can always tell the cars that weren’t broken in properly. They are the ones smoking on the side of the road.
Yep. And all those that do, know why and how to do it.
Yeah put key in and drive it. Coming from someone who owns brand new vehicles into the 240k range without serious issues.
MolaKule
Staff member
And this is the way I usually do run-in. After the first 20 miles, I drove it on a 500 mile trip and then changed the oil and filter. The last time I checked, this Nissan PathFinder (3.5L) had 375,000+ miles on it.
Yes, take it easy on that new engine. The computer on the new Corvettes will not allow it to go past a certain RPM and they do have a break in period. I think it's 500 miles.
I break them in and do a very early drop of the factory fill, and a couple of short OCI's after. Some agree, some don't. Keep one thing in mind if we're talking about new car engines. I prefer to order a car rather than take one from a dealer's inventory. Cars that sit in inventory are often moved around by lot boys, or as we called them, lot monkeys. They typically start them cold rev them up, and/or beat the hell out of them cold. The longer they sit in inventory the more they get moved and beaten. Ordering one lowers that risk considerably and odds are it will have under 5 or so miles on the clock. Car fanatics or people that worked at a new car dealership will usually agree. I'm sure I'll be reading more of the usual rebuttal about how long cars last running the factory fill 10K miles, and a slew of other stories. In that case do what makes you happy.
Well, I still own two of the vehicles that I bought new. My 98 Chevy truck with the 5.7L and my 2014 Mustang GT with the 5.0L. On the truck, I followed the break in procedure listed in the owner's manual which stated to not drive at constant speeds, no agressive driving, or go over a certain rpms or speed for the first 500 miles. The engine in this truck has always used some oil in between oil changes and I have always changed it every 3,000 miles per the manual.
On the Mustang, it says something similar in the owner's manual but with this car, I got on it hard several times and let it compression brake down to idle. The engine in it has never used any oil. I change the oil in it every 5,000 miles. I had read in several places that this is the correct way to break an engine is so I thought I would try it. It seems to have worked.
I know these engines are totally different in design and years apart but the going easy on the truck for 500 miles didn't seem to seat the rings like they should have been.
On the Mustang, it says something similar in the owner's manual but with this car, I got on it hard several times and let it compression brake down to idle. The engine in it has never used any oil. I change the oil in it every 5,000 miles. I had read in several places that this is the correct way to break an engine is so I thought I would try it. It seems to have worked.
I know these engines are totally different in design and years apart but the going easy on the truck for 500 miles didn't seem to seat the rings like they should have been.
When I bought my 2023 Cadillac XT4 with GM's 2.0L turbo, it didn't shift into 9th speed until it had 500 miles. I was making an interstate trip and I noticed it shift. I looked at the speedo and I noticed it had 500 miles.
