Here's a few comments:
1) I don't think TOY will mind people like myself who've upgraded to synthetic oil and changing it every 6-7k miles instead of 5k miles with conventional oil since synthetic has many advantages/benefits over dino, IMO. I could be wrong about the 5k thing, but I really doubt it. Besides, how can TOY prove that the intervals were 6-7k or any other mileage interval? Some Amsoil products allow 15k-25k mile intervals (following their instructions) with only an add'l change of the filter half way thru an interval.
2) that 3k or 3750 miles oil change interval isn't a must (in most cases, it's false). There's many factors involved in determining the oil change interval such as: oil type (dino or syn), towing, driving style, driving environment including climate, oil filter size, oil capacity, etc. Many (newer) german vehicles only require an oil change once a year or every 10k miles. My dad's ML320 has a 3.2L V6 as compared to my 4R's 4.0L V6, but the oil capacity are 8.3qts and 5.5qts (i think), respectively. He takes it in for an oil change once a year, eventhough he drive less than 6k mi/yr and the scheduled maintenance is free for the 1st 4yrs.
3) as for a new vehicle that originally have dino oil and changing it to synthetic too early, I don't think it's a big deal since most engine parts nowadays are microfinished and don't really need to wear in evenly. I understand that certain parts do need to wear in properly though, such as piston rings. However, many german vehicles come straight from the factory w/synthetic oil. My mechanic (my buddy's dad), told me that german automakers set longer intervals so that in the long run, there may be more problems and more service jobs for them. So after the 1st 4 years of free scheduled maintenance, you're on your on if things go bad which might have been contributed by not changing the oil more often. He changes the oil in his daughter-in-law's 325i at the 6 month interval, in between the annual free scheduled oil change & maintenance during the 1st 4yrs. I think the automakers (german) do this as part of a psychological thing too. Would a person think that changing the oil once a year (or 10k miles) & paying close to $100 for the service is saving $$$ versus another who changes it every 5k (or 6 months)? They may think that their vehicle is "low maintenance" if they only need to take it in for an oil change once a year.
Just my 2 cents
*side note: do any of you ever notice how WCC adds Synthec to these junkers w/many many miles on the odo after they pimp the ride? I'm not gonna go too much into the details, but I think some of you know what I'm talking about
