My Fiesta had a full Milltek and a panel filter, it'd show 140mph on the Speedo, down a big fucking hill, but you were doing about 125 if you were lucky. Your 1.6 Focus does not do 140mph, they're not even geared to that at the limiter, but it wouldn't pull to the limiter in 5th anyway!

Mo Mo Mo ya boat, gently off a cliff.