Here's what I found when I googled for information on this so-called
law:

http://www.answerbag.com/q_view/35468

DMc

On Sun, Dec 27, 2009 at 5:02 PM, Dave Mcneely wrote:

> On Sun, Dec 27, 2009 at 3:19 PM, Rob wrote:
>
>
>> Most of the JDM engines I've seen for sale come tested and
>> guaranteed. There is some sort of Japanese law to require new cars
>> every 30k-50k miles, you can look it up and read about it on line.
>>
>> Rob
>
> I've been told that such a law exists, supposedly as an environmental
> protection device.  However, it was not told to me that it was a new
> car
> (certainly not), but that the engine had to be replaced.  At any rate,
> that is supposed to be why so many Japanese engines are available for
> import.  However, my son-in-law bought one of these imported engines,
> and found to his dismay that the engine had been used hard, and
> further
> investigation led him to the conclusion that, yes the engines are
> available, and mileage is low.  However, since the users know that
> they
> will have to replace the engine anyway, they don't particularly take
> care of them.
>
> None of this should be taken as gospel, since I am only reported
> second
> hand experience, and third or further removed information.
>
> David Mc