Engine Break in - when is it considered actually broken in?

I personally noticed that my car appeared broken in about 2,000 miles but it was probably between about 5,000 and 10,000 miles before I'd have said it was nicely bedded in and I was getting max mpg's.

Guess everyones driving style is different but if you take it easy for about 2,000 miles you should be OK.

 

You don't need to work at breaking it in. These are modern engines, and they come from the factory with parts that fit pretty well. It's not like the old days where the moving parts machined themselves into shape and left a bunch of metal in the oil.

Obviously rings need to seat, and a few other minor things, but other than that don't worry about it. Avoid driving like a race car driver for the first 400 miles: no jackrabbit starts, and avoid panic braking. That's all there is too it.

Grumpy's comment about 2,000 miles has to do with when the car runs at its most efficient level. Tires wear in, bearings smooth out, all of the engine parts are happy with each other, plus you learn how to drive a Prius in that time. The 2,000 mile figure isn't a period for you to baby the car, it's just a good estimate of how long it takes to see the best mileage.

Tom

 

Since your question relates to being "broken in" related to fuel consumption (and not from a mechanical perspective--the owners manual discusses that), my guess would be anywhere from 1,000 to 2,000 miles would do it.

Plus the driver needs to be "broken in" regarding driving style. I know personally it took a while to get used to the fact that you're not going to jump off the line like a jack rabbit, and to not try to push the car to do something it wasn't optimized for.

 

I agree, modern engines which now come from the factory with synthetic oil are different. Their manufacturing tolerances and materials are also much improved.

I remember the break-in procedures for older BMW's, they were very specific and were supposed to be strictly adhered to. 500 mile oil change, 1500 mile oil change (with other stuff), no more than 3500 rpm for the 1st 1500 miles, vary rpm a lot, etc.

The older engines required a lot of "bedding" of the friction parts and produced a lot of metal in the oil during the process.

 

This is good to know esp. because my Prius came to me with 169 mi on the odo, having been driven across the state from another dealer to get to my local dealer, and who knows what driving monkey they got to deliver it and how that person drove it.

 

If you're a first time Prius owner, like me, it's probably you that need breaking in more than the car. I've got 5K on mine and am now pretty comfortable driving it.

 

What break-in? Like qbee2 says, modern engineering is so advance and precise, engine does not require break-in period anymore. The only break-in you'd need is your driving habits. You'd need to re-adjust the driving habits in order to reap the best fuel savings out of the Prius.

 

Let's assume this is true (which I believe to be true, but I'm an idiot). There was another recent thread which talked about some cars having "break in fluid" with the oil, such that you wouldn't want to change your oil too early to allow these fluids to do their things. These 2 concepts don't quite work well with each other.

Also, I'm sure you shouldn't max out the engine too soon. Right? So maybe there is a short break in period, but more like the initial time when you should gradually increase speed, acceleration, etc. rather than just floor it (save that for your street race with the new Porsche your neighbor just bought).

Mike

 

As far as we know, Toyota doesn't use any special break-in oil (i.e. no extra additives), though Honda does apparently. The manual does indeed state to take it easy in the beginning...it's just advice to ensure you get a typically long life out of your Toyota.

 

I think one of the most important statements in your post is where you say "plus you learn how to drive a Prius in that time..." Because it took me almost a year to get used to it after having a couple Avalons. (i now have 3,075 miles on it). The Prius is certainly not an Avalon, but I've come to depend onand trust Toyota quality. Some of the things I did not think thru was the idea of replacing the traction battery after 8 years, and getting used to a whole new driving concept/experience. The Pruis is quite radical in many ways compared to a regular ICE car. I find it fun to drive, economical, noisy, and some rattles - and much bullying from other drivers who like to get right in your face with their huge grilles. You have to drive extra defensively. Thanks.

 

See page 151 of the US-Canada users manual.
No sudden stops for the first 200 miles.
Don't drive at extremely high speed or constant speed for extended periods & avoid sudden acceleration for the first 600 miles (1200miles in the UK manual ??)