New Car Break-in Period - Don't use cruise control?

I picked up my 2003 Honda Civic yesterday and the salesman told me that, in addition to avoiding rapid acceleration and being easy on the brakes, that I shouldn’t use the cruise control for the first 500 miles. I read the owner’s manual last night and it doesn’t say anything in the break-in period section about not using the cruise control. Does anyone know why I was told this?

It’s not really a question of using the cruise control. It is recommended that during the initial break in period the engine speed should not remain constant for long periods. Engine speed should vary but you should avoid hard accelleration. Be gentle! It’s not a question of breaking in or harming the cruise control itself.

That is geneally good advice. The theory is that you should not keep a constant speed for long during the first few hundred miles. It is recommended that you change speed every 5 - 10 minutes so that the engine and transmission can break in over a range of speeds and using the cruise control on a long stretch of highway would defeat this goal.

Thank you. I should have said I understood that it was to vary the speed and wouldn’t harm the cruise mechanism. What I should have asked is, why do I need to vary the speed? Also, if it’s so important why isn’t it mentioned in the owner’s manual?

Thanks for the link. Curious that Honda doesn’t even mention this.

I’ll also add ;

Breaking-in of new engines is not as critical as it used to be. Engines are now built to much closer tolerances so in all likelihood it would be difficult to distinguish between a properly broken in engine and one where no special attention was paid. However, it’s still a good idea to pay attention to breaking it in properly. Theres nothing to lose.

On older engines it was claimed that if a new engine was run for long period at a constant speed it would develop a “flat spot” in its performance. In other words, the engine would tend to run well at that speed but would underperform at other speeds.

The same theories apply to the breaking-in the brake system. Avoid sudden stops! The brake parts are “mating” with each other when they are new and over-stressing them can foul up the process. When disk brakes became common it was claimed that this was especially important. It was said that a sudden stop on a new disk brake could actually warp the disk because of the sudden heat rise. Again, this potential problem may have been solved with advanced design and closer tolerance.

Really? Proper break in procedures are listed in the manual for my wife’s 2001 Accord V-6.

Either way, it sounds like you had a good salesman; it’s nice when they take the time to explain things like break in that will ultimately make your enjoyment of the car and the utility you get from it so much better over the long haul.

What spartydog said about modern engines requiring less physical break in is true. But as tecnology marches on new reasons come along as well. Another reason for varying the throttle position early on is that the electronic throttle bodies and engine computers need several miles to properly calibrate themselves.

That said, these days it is not generally considered a bad idea to use higher rpms and more throttle towards the very end of your break in period, and is actually desireable with modern engines. The high pressure of high RPMS and hard acceleration are needed to make sure the piston rings and cylinder walls wear in and mate properly. However, ther heat and stress this generates means that you should only do it once you’ve given the rest of then parts a chance to break in by driving gently.

This guy has a pretty interesting method for new Hondas:

Break-in procedures are listed but they don’t mention not using the cruise control or varying the speed.

*What is the break-in period of my Honda?

Help assure your vehicle’s future reliability and performance by paying extra attention to how you drive during the first 600 miles (1,000 kilometers). During this period:

Avoid full-throttle starts and rapid acceleration.
Avoid hard braking. New brakes need to be broken in by moderate use for the first 200 miles (300 km). *

That’s it. I even checked the Honda owner-link web site and it says the same thing. Not a word about the cruise.

handy, those are some interesting ideas to say the least. I’m glad I’m past his 20 mile break-in window so I won’t be tempted to try them.

How sure are you about this? How long ago do you mean by “old”? I mean, what you are saying definately makes sense, but engines run at higher RPM’s these days. Granted they have better lubrication systems too.

On what grounds do you say this? Why would everyone else in the world make a big deal about this, but you say it doesn’t matter? A kid I knew got a new Mustang and blew the engine up during the break-in stage on the highway, it mattered to his car…

Not trying to attack you, just wondering.

“handy, those are some interesting ideas to say the least.”

Yep, he (guy who wrote article) seemed the type of guy who probably takes better care of his car than he takes care of his wife…

My wife just picked up an Infiniti. The break-in instructions cryptically say “don’t run the engine over 4000 RPM the first 1200 miles.” That has to be wrong. They must mean, “don’t run the engine over 4000 RPM for any length of time, especially at high speeds.” I’ve never heard of breaking in a vehicle without occasional bursts up to the higher RPMs - as per Handy’s link.

Generally speaking, I would just avoid driving crazy or too consistently, especially for the first few hundred miles. Vary speed, gears, and take it easy on the brakes, unless you have to stop to avoid an accident. Break in comes after life.

This instruction is consistent with BMW’s recommendation not to exceed 2/3rds maximum RPM (the lowest RPM on the redline) in any gear during the break in period.

My WAG is anything in excess of 2/3rds of an overrev during break-in is potentially too stressful on an engine.

Information that was passed on to me by a master mechanic.

Newer engines tend to be smaller, more precise, better engineered, better materials, computer monitored and generally run smoother. Better lubrication is definitely a factor. I believe it was during the '80 that the U.S. automakers retooled their engine plants in response to Japanese competition so the difference between old and new would be in that time frame.

I’m not suggesting that engine break-in should be ignored but I don’t agree that “everone else in the world makes a big deal out of it”. With many of the cars on the road no attention is given to break-in". Rental cars, police cars, taxis and fleet cars just get run with no consideration of break-in. Many of them do fine for 100K+ miles.

As for your friend’s Mustang, the engine was probably either defective or abused. I doubt that break-in had anything to do with the engine failure. Break-in is to get the engine to run right, its not a matter of trying to prevent engine failure. That can happen with properly broken in engines.

Think of it like a baseball glove. You break it in to get it to feel right and work at its best. Break in will not save it if it is abused or misused.

I have broke in many new cars over the years. I drive them the first day just like I will be driving them from now on. (including one Honda)

Bought a new Lincoln in 99, went from the dealer on a 800 mile trip. I hit the interstate, set the speed control at 73, that is where I always drive. I put 75,000 on it, never a problem.

Broke in the one I got now almost the same way

The manual says:
There is no particular breaking-in rules for your vehicle.
During the first 100 miles vary speeds frequently.:rolleyes:

Dealers don’t always have the correct answer… They said I couldn’t tow a Honda with a automatic transmission without damage to the transmission. I towed it about 30,00 miles… no damage. :smiley: