Hi, I will add to this ancient thread...

I use 5w-30 Mobil 1 on the 92 Civic si (eg). I change every 2nd to 3rd track day along with the filter (K&N). From reading this, I would be inclined to change over to NAPA gold filters...

Any thoughts on Redline 30wt on a stock bottom-ended Eg? I am tempted to purchase and install some before NARRC runoffs - but don't what to bet HP and my engine. The redline racing oil descriptions go as follows:

SAE 20 (5W20): Drag racing and single-lap qualifying, where the lowest internal friction is desired.
SAE 30 (10W30): Sustained high-speed use in well-balanced racing engines where low internal friction is desired.
SAE 40 (15W40): High-temperature use or when widely varying engine RPM may be encountered.
SAE 50 (15W50): Extremely high temperatures, or when engine durability is the primary concern.
SAE 60 (20W60): Alcohol burning engines.