Duralube
I don't know if this helps but I used duralube on my old civic 1989 si, and it "seemed" like it helped, but then again the honda owners manual says those things don't help the engine.
I started putting that dura lube stuff in my old 1992 Camry religiously when it hit 200,000 kms when I got rid of it for my civic it had just shy of 300,000 kms on it. I don't know if it helped. But my engine ran puuurrrrfectly... It's just everything else started falling apart and costing way too much to fix.





