You must not have a cluster out of a C2. I have put two different C2 Carrera clusters in mine and in both cases the fuel gauge is spot on. If it had only worked correctly with the first cluster, I might have considered myself lucky, but when both worked correctly, I have to assume that it's because I used the correct cluster.
One difference I did find is that the first cluster I used was from an '03 and the oil level could be checked with the engine running, while the second cluster (from an '02) requires that the engine be turned off, but the key on.
First Cluster
Second Cluster
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