Can a guy use one of these for sleds, the kind the rpm lead hooks around the sparkplug wire? If so would they be as accurate as the one that I believe hooks to the lighting coil? What about the cold weather, would it affect it? Thanks

i ran a dt32sn for three years no probs mine didnt hook on the spark plug for tach reading. when u hook up the power wire it gets the tach signal from that.