I took possession of my boat about 6 weeks ago. It's a 2001 Catalina 36 MK2 in very good shape. The fuel tank capacity is listed as 25 gallons. I have read that it uses about 0.8 gallons/hour. I have twice run the tank to empty on the gauge and was full at 20 gallons pumped in. The distance motoring was less than expected for 25 gallons at 0.8 gallons/hour and 5.5 knots. When the gauge is on zero, it looks like I still have 5 gallons of fuel. Is this everyone's experience?
My 2003 sounds like it the opposite of yours boat. When my gauge first starts to show movement around the “F” mark I can add 9 gals to the tank before it’s full. The good news on the gauge is it’s repeatable so you just need to determine the actual amount of fuel in the tank for a given reading.
Bob Wilson
S/V Morning Breeze
2003 Catalina 36, Hull 2122
York River Yacht Club
Williamsburg, VA
Rich,
I am a firm dis-believer in fuel gauges, especially in boats. They are notoriously inaccurate. I suggest you keep a simple log of engine hours and gallons used to fill your tank. I did that with my C36 and do it with my current C400. Over 18 years I averaged 0.54/gal per hour with the M25XP. When I pulled up to a fuel dock, I could tell them within a gallon or two how much I would need. Your mileage may vary, depending on the RPM you normally cruise at. Somewhere on this site is a graph of gal/hr based on different RPM's. Hint: if you keep the RPM's in the 27-2800 range, your engine will SUCK down the diesel!! :-) Hope this helps.
PS-I would help a bunch if you were to complete your "signature", allowing people to answer your questions more specific to your boat/motor/rig/area.
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT