Sigma-galant.com

According to my GPS..when my Sigma speedo is reading 100kph , I am actually doing 91kph. Which is probably the reason for a lot of fist waving, headlight flashing and tail gating in 100kph zones

possibly. however new car read slow too. 5-6km is normal for some of the work cars i use, territory, Prado, hilux etc.

so its no that much slower.

stick a taller tyre on the back of the car...it will improve accuracy and also drop a few rpm at hwy speeds

I ran a 235/60/R15 on my PP's under my wagon