Re: Boat with a 3.0 Mercruser?
It'll be great for cruising local lakes with a couple of people, probably disappointing compared to something with a 4.3L V6 if you are interested in any kind of watersports with several people in the boat. Expect a MAXIMUM speed in the low 30's. Only thing I didn't like about mine was that cruise speeds (mid-20's) are so close to max speed that it always felt like the equivalent of cruising down the freeway at 70 MPH in your car in second gear ....
Something was either wrong with your motor or your boat was larger than 18ft. I have a Sea Ray 185 Sport with a 3.0 and my top speed is a GPS proven 38MPH.
From Boat Test.com:
2006 Sea Ray 185 Sport
Test Power: 1 x 135-hp MerCruiser 3L
RPM MPH Knots
800 3.9 3.3
1000 4.6 4.0
1500 6.6 5.7
2000 8.0 6.9
2500 12.0 10.4
3000 20.8 18.0
3500 26.6 23.1
4000 31.0 27.0
4500 36.5 31.7
4750 39.0 33.9
From Boating Life.com
Sea Ray 175
* Vital Stats Length: 17'6"
* Beam: 7'
* Dry Weight: 2,100 lb.
* Seating/Weight Capacity: 7/900 lb.
* Fuel Capacity: 21 gal.
* Max HP: 135
* MSRP: (test boat w/ MerCruiser 3.0): $23,490
* NMMA certified: Yes
* Test Drive
* Test Engine: MerCruiser 3.0 Alpha
* Test Prop: 19-pitch aluminum
* Test Load: People (190 lb.); Fuel (21 gal.)
* Top Speed: 42.6 mph @ 5,000 rpm
* Time to Plane: 3.3 sec.
* Time to 30 mph: 8.5 sec.
* Minimum Planing Speed: 17.5 mph @ 2,600 rpm
From Boating Life.com
Stingray 185LX
* Vital Stats Length Overall: 18'5"
* Beam: 85"
* Dry Weight: 2,219 lb.
* People/Weight Capacity: 7/1,070 lb.
* Fuel Capacity: 21 gal.
* Maximum HP: 150
* MSRP (w/Volvo-Penta 3.0L GXi): $20,742
* NMMA Certified: Yes
* Test Drive Test Engine: Volvo-Penta 3.0L GXi
* Test Prop: 21-Inch Stainless Steel
* Test Load: People (225 lb.); Fuel (8 gal.)
* Top Speed: 49.9 mph @ 5,000 rpm
* Time to Plane: 3 sec.
* Time to 30 MPH: 7.0 sec
Saying that a 3.0 will only push a 18ft boat to a maximum top speed of the low 30's is just false information.