MTU vs CAT engines in the 1000-1200 hp range

CAT C18's by a long shot. Just have to stay on top of the aftercoolers and change them every 6 years. Aside from that, service network is the most extensive, least amount of issues, and parts are cheaper.

Thread split from previous discussion and retitled.

Neptunus did use Series 60, but not in this boat as Series 60's only went up to 800HP. We're talking about mid 2000's boats, so I'm guessing 10v2000's. The 1000HP Cat's are bullet proof. I've almost never run an MTU boat 2005 or newer that wasn't showing some sort of strange erroneous alarm...…..both brand new and old yachts. If not multiple alarms each day.

That is great information!
Thank you so much!

We are liking at a 2008 62 Neptunus
On Sea Trial it did get up to 2300 rpm ( C18 Cats) but would only go 28.3 mph
I am a little concerned. It will cost $4000 to survey this boat

I think it is supposed to go 31 mph top end

There is also one in Chicago with MTU’s but I don’t know if I could get it down the Mississippi

Could be anything and without surveying it, you have no idea. Did the Captain properly use the trim tabs, usually they'll get you almost 2 knots on that boat. Was the bottom and running gear perfectly clean? etc. etc. They generally cruised around 23 knots at 80%, 24 knots if light on fuel.

We had 50% fuel and water , no tender or personnel belongings and 3 people

Broker said a diver was on the boat a few days ago

Generally true.....However I've seen a bottom a little dirty not effect RPM's, and slow down the speed a few MPH in rare instances. Without knowing the boat, it's also entirely feasible that the boat is underpropped, and still turns rated RPM's with a little growth.

What was cruise speed at 80% load? Cruise????

22 knots at 2000 rpm

That's normal performance/speed for that boat. I wouldn't worry about the engines or performance. If you really like the boat, proceed with the survey and go from there, but would probably expect some this' and that's given the age and condition. I don't remember what the 62' ran at WOT because you hardly ever run yachts there, and I mostly ran 62's locally, maybe Lauderdale to Miami.....etc...… never ran one on a long trip, but ran a bunch of them locally. I did do a ton of trips on a few of the 55' expresses I managed.