I HAVE RAN FROM 468-555ci ALL 13.5 COMP TO 14.8 AND HAVE NEVER HAD A ISSUE. I RUN 40 DEGREES TIMING, AND NORMALLY SHIFT THEM AROUND 7000-7200. I HAVE RAN THIS FUEL SINCE 1999 AND HAVE WON MANY RACE'S AND MADE MANY PASSES WITH NO PROBLEMS. I MIX 8 OUNCES OF 2 CYCLE OIL IN 55 GALLONS OF FUEL AND WORKS GREAT.