car: alto cng 1000cc
plugs: denso w20exu
temp guage attains optimum temp in greater amount of time as it used to attain with w16exu. is the only reason use of cold plugs or what?
on h/w, once i noticed, the needle dropped a little down but after some time again attained the optimum temp, is this malfunctioning of thermostat valve/wiring or something else?
opinion needed, before i actually dig it out ?