Generally speaking, you should avoid driving at a constant speed (like a long ride) for the first 1100 miles or so. So, around town driving, with a little freeway thrown in, should do the trick.

I read this in a Toyota Owner's Manual. It MIGHT apply to Scion's as well. Ya think???

 

there is a problem with that link... it is for a motorcycle engine

 

Further into it the author states it applies to autos and snowmobiles as well, to all 4 stroke engines. So long as the cylinder seals the same way, it should apply. Now if there were just some guinea pigs to say how long the engine lasts. That site doesn't provide the long term results, since most of their engines are rebuilt to maximize performance and all that on a regular basis. But if the parts show no damage or wear after a season of racing (and I guess thousands of miles?), I doubt they would suddenly get worse than normal in the long run... maybe I'll be another Scion guinea pig... :?

 

I was told the same when I picked up my car at the dealership. They knew that I was driving back all the way to Vegas, but advised that I try to drive it in town in San Diego as much as possible, and try to take stops along the way to Vegas as much as possible. They said that if the engine is run at the same higher RPM for a long period of time, the valves will set high and I would get that "ticking" noise some here have complained about.

Well, I did just that and haven't had any noise from the engine at all....now at almost 1300 miles.

I've tried not to go above 4000 RPMs, but have reached 5k on a couple of occasions recently. As time progresses, I'll push the engine harder and harder...
That's the way I'm gonna break it in

 

These are my thoughts on this matter. The odometer may say 0 miles on it when it comes from the manufacturer, but you can't tell me they have never started the motor, never tested the motor, and have never broken in the motor. The manufacturer breaks in these motors before they ever put them in cars, they have to, they can't depend on the new owners of these vehicles to do it for them. I have had several new vehicles and I have driven every one of them hard from day one, hittin rev limiters and evrything. I have never had a problem, and will continue to follow this practice until I don't drive anymore.

 

Problems? Maybe not. Peak performance? Probably not.

 

From page 114 of the Scion xB Owner's Manual:

Your vehicle does not need an elaborate break-in. But following a few simple tips for the first 1600 km (1000 miles) can add to the fuel economy and long life of your vehicle.

- Avoid full throttle acceleration when starting or driving
- Avoid racing the engine
- Try to avoid hard stops during the first 300 km (200 miles)
- Do not drive slowly with the MANUAL transmission in high gear
- Do not drive for a long time at any single speed, either fast OR slow

 

i read this guys theory the day before i got mine and ever since the day i got it i drive it like a race car eveything is perfect still i have 8300 miles on it since jan 31 and everything perfect and i get about 30 mpg and no noises just very nice and like mentioned earlier this would let you know if its a lemon engine and i didnt know if the theory was right but the dealer never told me how to drive it and besides i wne back in and talked to the service manager about the engine internals and specs and the said that these motors are throw away motors he said if the overheat once 1 time this is the service manager for about 5 years said the engine is trashed thrown away and he said he coul get me a tranny and engine for about 700 bucks so all you no motor heads ____ty for you cuz your gonna have to replace your engines cuz i know about 5 girls who just let there caroverheat and blow head gaskets but i would worry about the little 1.5 its not like itll kill ya if you have to take it back in to get a free brand new engine if yours blows up from his theory but mine didnt or didnt yet lol peace
ps. "dont live your life in fear its the only way to get smarter is to f*ck up"