Digital tach. hr. meter wire

I have a digital tach./hr. meter like this http://pages.ebay.com/motors/link/?n...092102&alt=web . I'd like to mount it on the dashboard. The first question is, çan I lenthen the tach.wire without affecting the device's accuracy? Second, there is a black wire coming off the device that goes into a black plastic piece that splits off the black wire into a red and a white wire. Should I lengthen the black wire or the red and white wires, or does it not matter. Red wraps around a plug wire and white appears to be a ground. The directions don't address the white wire.