Most speedo's aren't 100% accurate after 80-ish mph...so I'm guessing it's your speedo. I COULD have been a mild tuner, but I"m not certain. I know in my Neon, when I got it up to 120+ on the speedo (Stops at 120), I was only doing about 115-ish. (Got clocked by a COP in the AZ desert and NO ticket. He was confused on how a 1998 Stock-looking Neon got up that fast!!! LOL
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