Hi, by the people at www.saab-parts.eu I now got a longer e-mail, where with detailed reasons is warned of the use of synthetic motor oils. (e.g. “…absolutely lethal”. Main reason: at the cold start low quantities of gasoline would be landed in the oil. With mineral oils no problem, but petrol does not deal with synthetic oils, which ultimately leads to oil sludge, burnout and clogged oil sieve. If the oil sieve is dense, the engine is quickly over. It is also justified that the flat part of the oil tank lies directly above the cat, thus very hot, which leads to the loss of the synthetic oil gasoline mixture. Urgent advice: expand oil sieves and clean and only take mineral oil (e.g. 10W-30/40). For a Saab engine is the expensive Snynthetiköl nothing. Here is the link to this info. http://www.saab-parts.eu/DEN-Stu-Stu-Stu-Stu-Stu-Stu-Stu-Stu-Stu-Stu-Stu-Stu-Stu-Stu-Stu-Stu-Stu-Stu-Stu-Stu-s.