hey guys my buddy has a 1990 volvo 240 dl which has the 2.3 inline 4 i believe. he has 150k miles appx. and he wants to start doing his own oil changes but he doesn't have an owners manual so he doesn't know how much oil it takes and what weight should be used...we live in san diego so its mild year around, does anyone have any info on these cars? thanks for your time