By rev counter I mean the gauge that shows rpm/min (guess it's call a tachometer). Can the 4-cyl one be modified to divide by 3 ? Searching on the net I found that on same other car makes it's possible.

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)