i use Mobil1 5w-30 synthetic. probably the best stuff without going a bit higher, ie Redline and Motul. however, the oil filter is another story. after reading this
OIL FILTER STUDY, i was determined not to buy Fram. it's not an official study, but somebody's interpretation, but it holds some key observations in it. below are excerpts taken from the site:
Basically, filters to AVOID:
Fram Extra Guard
Years ago Fram was a quality filter manufacturer. Now their standard filter (the radioactive-orange cans) is one of the worst out there. It features cardboard end caps for the filter element that are glued in place. The rubber anti-drainback valve seals against the cardboard and frequently leaks, causing dirty oil to drain back into the pan. The bypass valves are plastic and are sometimes not molded correctly, which allows them to leak all the time. The stamped-metal threaded end is weakly constructed and it has smaller and fewer oil inlet holes, which may restrict flow. I had one of these filters fail in my previous car. The filter element collapsed and bits of filter and glue were circuilating through my system. The oil passge to the head became blocked and the head got so hot from oil starvation that it actually melted the vacuum lines connected to it as well as the wires near it.
Fram Double Guard
Another bad filter idea brought to you by your friends at Fram. The filter itself is a slightly improved design over the Fram Extra Guard, but still uses the same filter element. It has a silicone anti-drainback valve, a quality pressure releif valve, and enough inlet holes for good flow. The big problem is that they are trying to cash in on the Slick 50 craze. They impregnate the filter element with bits of Teflon like that found in Slick 50. As with Slick 50, Teflon is a solid and does not belong in an engine. It cannot get into the parts of the engine that oil can and therefore does nothing. Also, as the filter gets dirty, it ends up filtering the Teflon right out. Dupont (the manufacturer of Teflon) does not recommend Teflon for use in internal combustion engines. Please do not waste your money on this filter.
Penzoil
This filter is a Fram! It is the exact same design as the Fram Extra Guard filter and it is junk. On the up side, it costs $1 less than the Fram version.
Quaker State
This is another Fram Extra Guard that I have seen at K-mart. It used to be a Purolator, but Quaker State is now owned/controlled by Penzoil...
). I also got a Bosch filter(around $4). The Fram Suregrip was about half the price of the others, but the Bosch offered the best filtration. They had one brand for like $12, but that's way too expensive. I never realized how small these filters are. It looks like they belong on a lawnmower, not a car engine!!
