Jp4 does work pretty good but the 2013 and 2057 will give more top end and fuel economy. And Like Ron said he new versions are thicker and they also have a reinforced stinger. I have been racing mine for a few gallons now with no dents or damage They are Really strong pipes, If all you have is a jp4 it will work but you will definitly see better runtimes and performance with the 2013 or 2057. The 2056 does work good too but it takes quite a bit of power away.2013 tons of snap on bottom and killer top end....2057 a little softer(smoother) on bottom and same or a little better on top with slightly better runtime than the 2013 which already gets very good mileage with the B5. hope this helps!