How Do You "Break In" Your New Car

[TGallant]

Back in the day, it was a truism that you were supposed to drive a car reasonably hard some time early in its life. (Not sure if mechanics or automakers ever really agreed with that.) With more modern cars, that train of thought seems to be considered obsolete.

Just to cover my bases, I took more of a middling position: within the break-in limitations recommended by Toyota, and only after putting over a thousand miles, I just did one tankful where I drove mostly in Sport mode (CVT), accelerated more aggressively than normal, and took it up to 90 for a few seconds several times. Nothing too crazy.

With all that, I still got 27.8 MPG (US), which in my opinion isn't bad for combined city/highway. The Corolla is only rated for 28 in the city, presumably not in Sport mode and with a lighter touch than I was giving it.

I filled up tonight .... back to driving nice.

Anyone else do anything special for breaking in a new car?

[Draigflag]

I guess it won't do the car any harm, but modern cars don't really need breaking in, they are built very well and are very reliable compared with cars a few decades ago. Tests are done on the production line now, my friend who worked for Nissan told me that Nissan apply full revs to thier engines for a solid 24 hours to test the components under extreme conditions!

[SteveMak]

I broke my current car in according to the manufacturer's recommendations. For the break-in period:

• Drive gently for the first 500 miles to allow the tire glaze (the stuff that prevents the compound from sticking to the mold) to wear off
• Don't brake hard if you can avoid it.
• Avoid high revs and hard acceleration.
• Vary the RPMs, rather than just locking it into cruise and driving on the highway for the entire break-in period.

With a turbocharged engine, if you want long turbine life, always do the following:

• Do not engage turbine until the engine is thoroughly warmed up. This is not just the water temp. It's the oil temp! If you don't have a turbo-boost gauge (most modern cars don't), drive extra gently during the oil warm-up period.
• Drive your car extra gently for several minutes before shutting the engine off. This allows the turbine to spin down. Do not blip your throttle before shutting the engine off.

You don't want to have the turbine spinning while it's not receiving a supply of fresh lubricating oil at a thoroughly warmed up viscosity.

[Jay2TheRescue]

IDK, all my cars have already been broken in by the time I buy them.

[TGallant]

Originally Posted by Jay2TheRescue

IDK, all my cars have already been broken in by the time I buy them.

Ha! I hear you there. I have bought new several times before (as in: 1988, 2001, and 2009), but mostly I buy cheap old cars. Long story why I bought new again when I thought I never would, but suffice to say that repairing other people's neglected vehicles was killing me.

[R.I.D.E.]

Inconsistent loads are best for best ring seating in any new engine, which works out to be best for engine on pulse and glide. High loads apply more pressure between the rings and cylinder walls and provide slightly better cylinder sealing.

I doubt the difference is that significant in modern engines built to modern tolerances, beginning with the Japanese manufacturers using 4 different standard sized piston-ring combinations based on the final honed tolerance of each individual cylinder wall.

When rebuilt and the cylinders are bored to match the selected piston size, the additional step of providing 4 different standard sized pistons to more closely match the ideal piston to cylinder wall tolerance is not possible when boring to match the piston is utilized in rebuilding. This is where the skill and experience of the machinist boring the cylinders becomes critical.

[benlovesgoddess]

When i got my new Hyundai i20, i asked the salesman and he said i didnt need to do anything. Several thousand miles later, i found a passage in the handbook saying otherwise!
With the Prius it was basically dont thrash it and dont drive at the same speed for any length of time in the first 1,000 miles.

[SteveMak]

Originally Posted by benlovesgoddess

When i got my new Hyundai i20, i asked the salesman and he said i didnt need to do anything. Several thousand miles later, i found a passage in the handbook saying otherwise!

I find that sadly, salespeople are amongst the least informed about product knowledge. They are schmoozers and deal closers. That's their skill set and talent. Nerdy guys who know the ins and outs of a product don't do well as salespeople.

[14Corolla]

Using 0W-20 oil. It should be tight. Shouldn't be much to breaking in.

I wanted to do what you did. Buy new. Unfortunately, my old car broke on me. Had to buy. The best mileage the previous 'owner' had on the computer was 36.8. I imagine it wasn't babied. It was in Denver. Am sure it was fed E10 fuel. I also knew the previous 'owner' had to keep up on the maintenance. It's all recorded on the computer and with Toyota. It was a lease vehicle. I'm also still under warranty for another 8k miles. Doesn't matter with a Toyota. They're good.
Also, fortunately, because of this car and not new. I was able to buy a home. So things worked out.
Didn't mean to babble on. Breaking in isn't much to worry about I'm sure.

[rfruth]

Another by the book guy here (just drive it normally)