Best cruising RPM for Mercruiser 3.0?

[2005Vip]

Just looking for advice on the best cruising RPM for my engine. I know that this will very depending on the prop, but I'm looking for a ball park. I know that WOT is 4200-4600 for it. Also how long is it safe to operate at WOT?

 

[achris]

Re: Best cruising RPM for Mercruiser 3.0?

How long is a piece of string? You'll get as many answers for your question as there are members of iBoats... :facepalm:

IN MY OPINION... Comfortable cruising depends on the weather. If you're looking for a rev range, anywhere between the speed at which the boat planes and about 75% throttle... For best fuel economy, you'll need to do the graphs, but generally around 65% throttle.

How long at WOT? Depends on a lot of things. Are you talking about the engine, the crew, the hull? For the engine, any engine in good condition and state of tune, without being over-propped shouldn't suffer when run at WOT. Obviously if you ONLY run at WOT the engine life will be shortened. If the engine already has mechanical problems, or is badly over-propped, then any running at WOT will risk serious damage.

I hope this helps....

Chris...........

 

[2005Vip]

Re: Best cruising RPM for Mercruiser 3.0?

How long is a piece of string? You'll get as many answers for your question as there are members of iBoats... :facepalm:

IN MY OPINION... Comfortable cruising depends on the weather. If you're looking for a rev range, anywhere between the speed at which the boat planes and about 75% throttle... For best fuel economy, you'll need to do the graphs, but generally around 65% throttle.

How long at WOT? Depends on a lot of things. Are you talking about the engine, the crew, the hull? For the engine, any engine in good condition and state of tune, without being over-propped shouldn't suffer when run at WOT. Obviously if you ONLY run at WOT the engine life will be shortened. If the engine already has mechanical problems, or is badly over-propped, then any running at WOT will risk serious damage.

I hope this helps....

Chris...........

Thank you.

 

[bonzoscott]

Re: Best cruising RPM for Mercruiser 3.0?

Cruising to me means just a bit more than planning out. That would be 2800-3000 RPM for most run-abouts. Depends on your boat size / weight / power ratio. Get her planed out, then move 500-800 RPM more. That may be 3000 or 3500 RPM in general. WOT is debatable. Factory Motors tend to come apart in the upper range of RPM when run in excess. 3/4 throttle and about 4000 RPM, motor will probably out last the boat.

 

[Cortes100]

Re: Best cruising RPM for Mercruiser 3.0?

I have an '08 SeaRay Sport 175 with the 3.0L engine. My WOT is 4800rpm.
Most of our pulling toys is in the 3000-3400 range. A nice gentle cruise in the 3200 range. It will run there all day long and you'll never run out of fuel. If the lake is calm, sometimes we cruise at 4000 rpm for 20 minutes without a hiccup. Purrs along just fine.
I only do the WOT once in a while to make sure it still gets to 4800, and then back it off.

 

[Grub54891]

Re: Best cruising RPM for Mercruiser 3.0?

1985 Larson,17' run it up to plane keep it there for a bit,back off about 3000 to 3500 and just cruise..... Got it a couple years ago,original motor,never touched till I got it,just rebuilt the carb. Now rebuilding the entire boat. Treat it right the motor will outlast the hull. Now once I'm done with the hull,I sometimes wonder how long the motor will hold up after the other work is done.....I think just fine,as compression is 150# across the board,and never misses a beat. It'll last till I'm done with it,say another 20 years?? LOL

 

[tinkerguy70]

Re: Best cruising RPM for Mercruiser 3.0?

In our 17' Sylvan runabout with a 3.0, I generally run 3000 to 3500ish depending on the weather and water conditions. Obviously, pulling toys or heavier loads will change those numbers, but I find I can keep her up on a good plane at 3500 or less.