My ED30 speedo was not that accurate about 6 mph out at 80 but ED35 (both of them) only 2 mph out at 80 using the same GPS. May be down to running 19's (225/35) as rolling circumference is very slightly larger than 18's (225/40). Worst was my first MK6 which was 8 mph out at 80. Not sure what they would be at those sorts of speeds, wouldn't want to by trying to look at my GPS either unless I was on a closed road or track. However as mine has not been mapped I don't know what the max on the speedo would read may be an indicated 155-160?