Recommend a Tachometer for maintenance / tune ups 1 Recommend a Tachometer for maintenance / tune ups I'm new to engine maintenance, am without a tach, and my repair manuals are telling me I'll need one! I searched the forums but mainly come up with in-dash gauges. I'm looking for something wired just for tune ups. Can anyone recommend one that will work easily with my 1986 2.5l 150 4 Cyl? Photocell / laser styles seem to be the most common these days but I'm not sure if that's a good way to go. Thanks Rear Axle: Dana 60 Spooled Disc Brakes Axle Gear Ratio: 5.38 Tires: 42X15-17 TSL