The A6M2 had 145USG of internal fuel and the same 87USG drop tank as the A6M3. The A6M2 would cruise a few mph slower than the A6M3 and was about 5-10mph slower at maximum power.
Wow giving what I saw in the chart there fir the A6M3 that is a slow cruse but a lot of hours in the air. Which is a good thing when on patrol for enemy aircraft.
Some of the super long ranges attributed to the Zero (especially A6M2) were flying at minimum speed and maximum lean fuel mix conditions. Saburo Sakai claims to have flown for 12 hours like that!
Realistic figures are around 1,150 miles at 230 mph for Model 21,22 and 52. The Model 32 and Model 52c on "fighter-bombers" got about 950 miles.
Sakai said he got more turns of the prop for a gallon of gas (well, OK, he didn't quite word it that way) than anyone in the Tainan Wing. About 17 gallons per hour (converted from metric of course). The average was something under 20, IIRC.