Tick Marks on the Speedo

Tick Marks on the Speedo

I noticed some marks on my 280SE 4.5 speedometer and thought that they might indicate top speed in each gear. One mark is an "I" like the Roman Numeral 1, one is a II. But I've been chicken to go that fast in each. However, the car "feels" like it would do it. Any of you actually tried it?


As Richard says if the engine is OK them no problem. I have found that these marks are 200-400rpm below the actual redline on some cars. Your 4.5 for example should have a centrafugal cutout on the rotor button. So you cant over rev the engine if it is working. (hell of a way to find out if it isn't) Did the US 280SE 4.5 have a rev counter like the 6.3?? If so compare engine revs to the marks on the speedo. Also if you are looking for the ultimate in acceleration remember that in most cases there is no point reving the engine past the point of maximum torque or horsepower. This point is usually approx 1000rpm below the redline. My 280E race car is faster in a straight line if I dont go all the way to the marks on the speedo in each gear, even through the engine will rev to 8500rpm. (dont try this with a standard twin cam)

John Greene