Most efficient cruising speed on 2252-gctid385582

[Guest]

I went on my first ocean voyage today on my new to me 2255. Went out to Friday Harbor for dinner and then came back home.

The boat is a 1996 2252 hardtop with a 5.7 Mercruiser and Alpha One.

I cruised mainly at 3400rpm which equated to 26 to 29 mph. I briefly maxed it out at 36mph at 4200rpm.

I topped it off before and after the trip. Trip is 60 miles, and I used 38.6 gallons at $4.49gal for a total of $173.68. Dinner was $21, launch fee was $7, so total cost was $201.68 for my dinner trip.

I was hoping for more than 1.5mpg on this boat. Am I "cruising" to fast?

Also, I think top speed should be faster. I think I saw a review somewhere that tested this boat with the 4.3 and topped out at 40ish.(that may have been without the hardtop).

[stargazerwa]

First off, I don't have the same boat, I have a 25' Maxum. I purchased a flow meter for my Navman chart plotter and here is what i found. My best is about 1.4 gal/nm at 3700 rpm with a non-factory four blade prop. Now that I have owned the boat for several years, you can just sort of feel when your in the sweet spot.

At 3300 I am sort of in a poor plane with a bit of wallow. At 3500 I am on plane but getting only 1.3 nm/gal. At 3700 the boat feels better, lifted more out of the water. My max rpm is about 4300 and I am not comfortable running the engine above 3700 rpm. An important part to getting good mileage is to trim the boat out well, trimming the out drive up helps me pick up an extra 2 knots.

If I have just one person sitting in the stern seat while on plane I drop down to 1.35 nm/gal. Your going to buy a lot of gas no matter what you do while running on a plane. You might try different trim options while watching your speed on a gps to see what makes sense for your boat.