Our fuel burn was considerably higher than what others reported. During our last CI I did the carb inspection, which includes replacing the metering needle, float valves, etc. We also found a bad left choke cable that may have been keeping the left side starting carb from shutting off completely. Afterward our fuel consumption dropped by at least 1/2 GPH in cruise. We'll never know for sure, but think at least part of that was from replacing worn fuel metering parts.
About the only time I see 22" MAP is during descent and in the pattern, though. Couldn't tell you what the fuel consumption is then.