[Old Tele man]

...while driving with cruise-control set at 65 mph, on flat/smooth highway, both the RPM and MPH displays continuously "jump/drift" up/down, ie:

65 mph (speedometer) = 64.4 - 65.0 - 65.6 mph on meter
2700 rpm (tachometer) = 2.68 - 2.70 - 2.72 rpm on meter

...the road is perfectly flat, there were no other cars either in front or beside me (I drive to work VERY early in the morning). And, I cannot detect ANY actual up/down changes in either speed or engine rpm (seat-of-pants or dash gauges), but the ecometer continuously cycles up/down by about 0.6 mph and 0.2 rpm.

...only the MPG-avg display is "constant," with understandable periodic changes resulting from traffic (truck windstreams), wind, road grade/slope, stoplights, etc.

...and, the MPG-inst display is even worse, with values randomly swinging between 99+mpg and 2mpg popping up under same conditions as for RPM and MPH.

...I'm on my fourth e-mail to Auto Meter asking "what gives?" But since the last two weren't answered, I'm not "...holding my breath...".