Volvo Repair: routine maintenance, bosch platinum, spring summer fall


Question
I recently purchased 2 used volvos, a 1995 960 and a 1996 850GLT.  Both from a dealer (who maintanied them) and both given the 44 point inspection.

They are a year old and have app. 10k miles added to them (both have app 120,000 miles.

I've read that volvo maintenance would change the brake fluid, coolant, trans & power steering fluid at 30k intervals.  How important is this?  Should I opt for synthetics where available?

I'm also using Mobil 1 (5W-30 winter, 10W-30 spring, summer, fall with 5000 mile changes and Mann filters, sound good?

Plugs may need changed if I follow the 30k interval, how about Bosch platinum to extend that time?

Live in Pittsburgh, should I re-apply undercoating this summer, if so, a friend swears by a mixture of light oil and greese, then let it sit and drip.

Anything else your experience shows I should do?

Thank you  

Answer
your mixture for undercoating is illegal in MOST states, something about being enviromentally unfriendly and all. in the PA area, you have no concerns with rust. these cars hold up very well. plugs should be changed every 30k, and if you have a turbo, platinums are called for. Do NOT use sythetics, other than engine oil. this can cause issues. if you stick to the volvo maintenance you will not need the added protection of synthetics