libra:.. its more than that.. i found out speedo is recaliberated to hit 180km much later for fuel cut,, (someone before me had already a fast car was using this speedo)
simple easy way to gain more top speed without fiddling with car computers,,lol.. and 17" got the blame:)
I hear people recaliberate when they use smaller dia tires for quicker acceleration and they want correct speed too