Correct me if I'm wrong, but I believe that it is generally a good idea to to keep a new car below 55 mph for the first couple hundred miles.

I know that the manual specifies 500 miles, but for what (I don't have it in front of me right now...)? I mean, I've been driving at around 80, 85 mph with just over 100 on the odometer (it's around 230 now), but even still, I never let the engine speed exceed 3,000 rpm. I would think that the engine's speed is more important than vehicular speed when breaking in a car.

So, please refresh my memory: What is it that's supposed to be done in those first 500 miles? Also, is my idea of keeping the RPM's below 3,000 for the first 500, 600 miles a satisfactory break-in? I mean, damn, at 80 mph, the engine speed is still just below 2,000 rpm. Redline, meanwhile, is over 6,000. (Excluding the Z06, I think.)

 

I would recommend what GM does - 500 miles under 55.

It may be the hardest thing to do (I know I had trouble) - but the way I look at it, why risk a high performance engine for a few days for a lifetime of enjoyment.

I'm not a mechanic or engine expert by any means, but I think there is some truth to letting the seals, parts, etc "get to know each other" a little bit before you put signficant stress on it. Just my .02

 

That's true, and I was a little worried about doing 80 on a virtually brand-new engine. But 1800 rpm or thereabouts - ALWAYS under 3000, like I said - isn't really stressful, is it?

Everyone else, I'd really like your thoughts on this.

 

keeping it under like 55 was tottally impossible for me the first 500 miles, so i used your strategy of the rpm thing and also didnt excelerate hard for the first 500 miles. :chevy :chevy :chevy

 

I also think there is more to it then just the motor. Your engine revs may be down, but your rear is just a function of over the road speed. Same with the transmission, output shaft speed will be directly linked to the wheels.

 

This is my opinion, based on my limited experience.
1) The break in recommendations are arbitrary and have not been derived by trial and error, or any sort of measurment.
2) The 55 mph is the easiest thing for GM to recommend. If you set an RPM level, it would be harder for some customers to understand (non car nuts like ourselves with autos wouldn't easily understand)
3) RPM limits at 3000 make the most sense to me regarding engine breakin, but the drive train could be sensitive to speed as above.
4) I think you could be too conserative when you break the car in. The advice I got during the breakin in was : (forum member) driving like a granny for 500 miles, then hammering it is bad for the engine, the rings wont be seated properly, drive it like you stole it. (dealer) drive the car during breakin in exactly like you will drive it normally.

That being said here is what I did.
1) First 250 miles, nothing above 3500 RPMs, very gentle on brakes, top speed less than 65.
2) Second 250 miles, push revs up to 5000 range, still gentle on brakes, no full throttle
3) Third 500 miles, very aggressive, red line and WOT on acceleration, "get those rings to where they normally will ride).

I now have 6000 miles, haven't burned a drop of oil, the engine runs very smooth without any piston slap, and it feels fast as a devil.

Good luck

 

Well, I guess I was going a bit fast, even with the RPM's down. It's not like that's going to hurt anything, though, is it? I'm gonna continue to keep those RPM's down for another hundred miles or so, and after that, little "excursions" to higher engine speeds.

It's okay, right...?

 

Don't worry, you'll be fine.

The post above about other parts is correct, though. GM wants everything to break in, not just the motor. Don't forget the brakes, too. A bunch of mild stops from 80 mph isn't the best way to bed them in.

 

The 55 mph is for the rearend to break-in properly. Improperly done, the rearend can begin to whine as milage increases. :flag

 

:iagree: I believe that this is mentioned in the video that came with my car.

 

Aren't you suppose to continually vary RPM to help the rings seat?