I don't yet own a GN but am looking. I am baffled by the spedometer which only goes up to 85 mph. I believe I read that, stock, they top off at about 120 or so. What's the deal with that?
Basically, that's the way a lot of Domestic cars were back in the mid-80s ... the dim era of 55 MPH speed limits.
The GN is a souped up Regal after all, so the speedo is the same as in the "slow" Regals.
The GNX came with a full set of decent gauges (Stewart Warner, if I remember correctly). In a GN, you bury the speedometer needle pretty quickly and then the only way to get speed from there on out is to use a scan tool. Stock chip limited the speed to the capability of the stock tires (about 122 MPH), but most aftermarket chips remove the limit.
A stock GN would probably do upper 130s flat out (and be tail happy doing it!) A couple mods and the car is a faster than that.
Car and driver in 86 said 124 mph, you can change the sppedo face and re calibrate to more mph also i think scanmaster goes up to 199 mph (not sure)
The datastream will allow for up to 255 mph (for those of you with the Saturn V booster rocket option
) I'd guess that most scan tools (ScanMaster, TurboLink, etc) will show up to that value.
The sability of the "stylized box" is something to e desired over 120. That is why NASCAR used all the spoilers and facia on these things. So please be careful