Hello all,

I am curious as to some opinions on breaking in a new engine. I have a 2015 Rubi that I'm picking up tomorrow, and I've heard conflicting things about the first 300-1000 miles.

Anyone have experience breaking in a new engine "the right way"? What does that consist of?

I read something that said

"For the first thousand miles, avoid constant speeds and throttle settings."

But then the user guide says:

"Drive moderately during the first 300 miles (500 km). After the initial 60 miles (100 km),
speeds up to 50 or 55 mph (80 or 90 km/h) are desirable."

Which is confusing by itself. Am I not supposed to go on a long trip in the first 1K miles? (>200 miles highway) Am I not supposed to go 50-55 during the first 60 miles? I want to break it in right so that it lasts as long as possible.

Any advice?

Thanks!

 

W.O.T.

Congrats! Some say take it easy on the engine, and some say give it hell. I drive normal with occasional high rpm pulls with the higher gears (3rd, 4th, or 5th) in the first couple hundred miles. Then just make sure you change the oil and filter at 1,000 - 1,500 miles. Don't stress it, enjoy it.

 

My put: For the first few hundred miles avoid cruise control. Be moderate in your speeds--55-65 max. After that, you're good to go. Change engine oil after 500 miles. Use conventional/dino oil, not synth. Change oil again at 2500-3000. Use synthetic. Follow the oil change light after that.

 

Thanks, I'm super stoked about it!

When you say avoid cruise control, are you saying its ok to do prolonged highway driving, but make sure that I vary my speed slightly and constantly? I am planning on picking it up and then driving about 200 miles, that's why I'm asking. Also, why use conventional oil for the first change? Doesn't it have synth from the factory? I heard its bad to use conv. after having used synth?

 

This is from the 2014 JK owner's manual. The 2015 is probably identical.

ENGINE BREAK-IN RECOMMENDATIONS
A long break-in period is not required for the engine and
drivetrain (transmission and axle) in your vehicle.
Drive moderately during the first 500 miles (800 km).
After the initial 60 miles (100 km), speeds up to 50 or
55 mph (80 or 90 km/h) are desirable.
While cruising, brief full-throttle acceleration within the
limits of local traffic laws contributes to a good break-in.
Wide-open throttle acceleration in low gear can be detrimental
and should be avoided. Trailer tow is not recommended
during break in period.

 

Yes, vary speed. I recommend conventional oil to let the rings seat. IDK if it has synth or dino from factory, but I do know there are lots of folks with modern engines complaining about oil consumption ... oil they can find no evidence of. I suspect it is because engines aren't breaking in properly on synth. It does not hurt to switch back to dino in a new engine. High mileage engines it is a no-no to switch to synth because you can have seepage. Again: This is my put on the issue. I have 146K miles on my 3.8 and go 6K miles without adding oil.

 

2012 jkur
I picked my jeep up at the dealer in Manassas, VA and drove straight to VA Beach. I kept it under 50 for the first 50 miles, pulled over and turned it off for 15 minutes. Started it up and varied between 55-75 the rest of the way (about 140 miles). That week, around town driving, I drove it at varying speeds, highway and in town. 34,000 miles, no issues, no oil burning, nothing. Many manufacturers mount the motor on a stand after final assembly and take them to the red line for a few minutes and varied run cycles under load before its ever dropped in a chassis. I saw this done at the Volvo plant in Sweden. Their logic? If it's going to blow, it will do it under the testing phase and shouldn't be a concern once it is on the car. My logic? It's under warranty. Run it. The old school mechanics I know, claim that you break it in the way you are going to drive it.

 

i put 7400 miles on mine before adding synthetic. I did 1st change at 3k and used petroleum,, at 7.4k did 2nd change did synthetic and will continue to. The engine does need to seat the rings and wear the cam/lifters, and everything else before you put in synthetic. If you just drive in a conservative manor with some good hard accelerations and avoid sitting at the same rpm for extended periods, you will be just fine. Congrats on the new toy

 

Awesome, thanks guys, you've given me a little more insight than the manual. Never had a brand new vehicle before, I'm sure I'm overthinking it a bit, but I tend to do that as I'm an engineer