HP4RU. Full-Synthetic Racing Ultra. Whether racing or for daily use, HP4RU improves clutch performance, delivers maximum horsepower and protects your engine better than any competitive brand! Meet Pro Honda HP4RU, a full synthetic, high performance, 4-stroke racing oil designed to provide a superior riding experience both on the track and over the road. Benefits: Smooth gear shifting. Precise clutch engagement. Reduced friction with no clutch slip. More horsepower (from less mechanical loss). Improved fluid cleanliness throughout oil change intervals. Pro Honda HP4RU is backward compatible with motorcycles that require 10W-30 or 10W-40.