x-post from maintenance forum:

I'm about to buy a 2005 RS (i.e. non-turbo), and was a little suprised to see the recc'd maintenance schedule:

oil every 3750 mi
spark plugs every 30k
major fluids every 30k
timing belt at 105k (nothing unusual there, pretty standard).

thanks to improved engine materials and tolerances, most modern cars have less frequent factory recc'd maintenance. E.g. oil every 5k or 7k (typical sedan), or every 10-15 k (porsches etc. running synthetic). platinum Spark plugs every 60k (some cars 100k !). coolant every 60k / 5 yrs (using long-life coolant, which is only compatible with modern engines).

Please don't bother with the "well it's always a good idea to change oil and fluids more frequently, it's cheap insurance" line--I'm miles ahead of you on that one.

The conclusion choices are a) Subaru is a little bit behind the times in terms of engine materials (liners, rings etc.) and design; or b) Subaru does in fact make a high-quality motor similar to Toyota etc., but for some reason is enforcing more maintenance just to be on the safe side.

My question is that since I'll rack up a LOT of hiway miles, and since I've had very positive experiences with other modern Japanese aluminum block/head cars, I'll probably do a) Mobil 1 or Amsoil synthetics every 5k miles, sometimes 6k b) Fluids every 30k, maybe 40k c) Spark plugs every 30-40K, depending on how they look when I pull one out.

Will subaru not honor the powertrain warranty if I go this route? Or do I have to pretend that the suby engine is more poorly engineered than the competition (I doubt it!), and thus requires more frequent maintenance...in order to get no warranty hassles?

thx.