Hey guys
I need an oil change in my 98 z. It has 111k miles on it, and im thinking f going synthetic. Its the first time ive changed it since i got her, so i dont know whats in there. should i use mobil 1 5w-30? And what is the stock oil capacity? I dont have a manual. Thanks

 

Choose any good quality 5w-30 oil synth or dyno.
put in 5.5 quarts if you use a normal filter. 6 quarts if you get the longer filter.

 

I use Castrol 10w30, but I see you live in a colder climate, so 5w30 might be a better choice. Unless you know the car has been run on synth its entire life I don't see the point in switching now from mineral-based to synth oil. The idea behind synth is that it prolongs engine life. But if using mineral based oil, and it is changed regularly the engine should last 200k miiles (unless it is severly abused in other ways e.g. overheating, over-revving, etc.) That's just me. I'm old school and have used mineral based for all of my cars since the late 70's and never had any issues.

Another important choice is the filter you use. Don't save a buck by buying an off brand cheapie oil filter! There are several very good quality low priced filters on the market. I use A/C, Purolator, or WIX. Fram is CRAP IMO. You can get any of the 3 brands I mentioned for about $3-$4 by shopping around a little.