What is considered "highway" for breakin? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

cybercoaster · 07-15-2012, 03:11 PM

So I have about 900 miles on my car all city driving following the breakin period rules. I am curious as to what are highway miles that we are not supposed to take the car on? I want to drive about 2 hrs away on the highway - is this to far or are highway miles considered a longer trip? Guess I could take each exit on the way to slow down some...

tsnow · 07-15-2012, 03:51 PM

The highway designation relates to extended periods at a steady state rpm, mph, and load. The powertrain will have a more effective brake in by varying rpm, speed and load.
GM also prefers brake in to occur below the upper limits of load, rpm and HP. Many opinions on this though.
City driving satisfies the GM method. Highway driving is fine, just mix it up often!

PNYSLAR · 07-15-2012, 03:54 PM

Even if you go on the highway it's all good, Just don't put the cruise control on.. Play with the accelerator..LOL Up, Down and all around.. Go slow then see how she likes to speed up. I'm also at 900~ so we are in the same boat and trying to get to the sacred 1500.

Russell James · 07-16-2012, 12:23 PM

Nothing bad will happen if you use cruise on the highway. The engine will still be seeing plenty of varying load.

I've taken many new cars on long highway trips, even a brand new 04 Z06 with 2 miles on it I took from MI to FL and back. That car turned out perfect.
Often a long trip coming up sparks me to buy a new vehicle. I'd bet I've taken at least a half dozen brand new cars on long highway trips. None of them had any issues.

Buy car, drive normal. It's easy as that.

Angrybird 12 · 07-16-2012, 12:28 PM

Drove ours back from Detroit right after picking it up most was interstate driving, but I varied my speed and also changed gears in manual to put the engine in different Rpm ranges. Never held the same RPMs for more than 10 minutes at a time.

snapp32e · 07-16-2012, 01:07 PM

I went against the grain and broke it in just as I've broken in every other new motor I've had. Essentially a hard break in. Not abusive but hard, there is a difference. Load the engine often and keep the speed down. No top speed runs. I still haven't had the car over 200km/hr even with 2500+km. I kept the WOT runs under 5000rpm for the first 200km then started walking them up to redline incrementally afterwards. That combined with a few other rules (frequent oil changes, etc.) and the obvious golden rules, no downshifting, never lug the engine, frequent cooldowns. With highway miles, I was and still do vary my gears consistently and often give it WOT runs to redline. Now with 2500+ km it feels crisp and strong, and I think it will continue to wake up even more yet. I know some here would call me an idiot to not follow GM's rules but I've never had an issue in the past with any engines longevity that I've done this with and don't believe this one to be any different. You get one chance to break in an engine, that's it. I prefer the power route. To each their own.

07-15-2012, 03:11 PM	#1
cybercoaster Drives: 2017 2SS 50th Anv, 1972 RS Join Date: Mar 2009 Location: Oklahoma City Posts: 1,588 View My Garage	What is considered "highway" for breakin? So I have about 900 miles on my car all city driving following the breakin period rules. I am curious as to what are highway miles that we are not supposed to take the car on? I want to drive about 2 hrs away on the highway - is this to far or are highway miles considered a longer trip? Guess I could take each exit on the way to slow down some...

07-15-2012, 03:54 PM	#3
PNYSLAR Summit White 2012 ZL1 M6 Drives: 2010 BLACK 2SS/RS M6 Delvd 8/24/9 Join Date: Jul 2008 Location: Elkmont, Alabama Posts: 435	Even if you go on the highway it's all good, Just don't put the cruise control on.. Play with the accelerator..LOL Up, Down and all around.. Go slow then see how she likes to speed up. I'm also at 900~ so we are in the same boat and trying to get to the sacred 1500. __________________ 2012 Summit White ZL1 Manual 6sp Blk 10 spoke, "Thanks Champion Chevrolet" delivered 6/9/2012 #1588

07-16-2012, 12:28 PM	#5
Angrybird 12 7 year Cancer Survivor! Drives: 17 Cruze RS, 07 G6 GT, 99 Astro Join Date: Dec 2007 Location: East Tennessee Posts: 21,546	Drove ours back from Detroit right after picking it up most was interstate driving, but I varied my speed and also changed gears in manual to put the engine in different Rpm ranges. Never held the same RPMs for more than 10 minutes at a time. __________________ Cancer's a bitch! Enjoy life while you can! LIVE, LOVE, DRIVE... The Bird is the word!

07-16-2012, 01:07 PM	#6
snapp32e Drives: '81-Z28/'07-Tundra/'12-ZL1/'13-Jeep Join Date: Oct 2011 Location: Canada Posts: 529	I went against the grain and broke it in just as I've broken in every other new motor I've had. Essentially a hard break in. Not abusive but hard, there is a difference. Load the engine often and keep the speed down. No top speed runs. I still haven't had the car over 200km/hr even with 2500+km. I kept the WOT runs under 5000rpm for the first 200km then started walking them up to redline incrementally afterwards. That combined with a few other rules (frequent oil changes, etc.) and the obvious golden rules, no downshifting, never lug the engine, frequent cooldowns. With highway miles, I was and still do vary my gears consistently and often give it WOT runs to redline. Now with 2500+ km it feels crisp and strong, and I think it will continue to wake up even more yet. I know some here would call me an idiot to not follow GM's rules but I've never had an issue in the past with any engines longevity that I've done this with and don't believe this one to be any different. You get one chance to break in an engine, that's it. I prefer the power route. To each their own. __________________ ZL1 #612

07-15-2012, 03:51 PM	#2
tsnow Drives: 12' ZL1, AGM 6M Join Date: Jun 2009 Location: 49th state Posts: 249	The highway designation relates to extended periods at a steady state rpm, mph, and load. The powertrain will have a more effective brake in by varying rpm, speed and load. GM also prefers brake in to occur below the upper limits of load, rpm and HP. Many opinions on this though. City driving satisfies the GM method. Highway driving is fine, just mix it up often!

07-16-2012, 12:23 PM	#4
Russell James Drives: '15 SS 1LE, '69 Z28 drag car Join Date: Dec 2009 Location: Mich Posts: 4,482	Nothing bad will happen if you use cruise on the highway. The engine will still be seeing plenty of varying load. I've taken many new cars on long highway trips, even a brand new 04 Z06 with 2 miles on it I took from MI to FL and back. That car turned out perfect. Often a long trip coming up sparks me to buy a new vehicle. I'd bet I've taken at least a half dozen brand new cars on long highway trips. None of them had any issues. Buy car, drive normal. It's easy as that.