RPM, wear, fuel economy

[Alaskabound]

I did get the Bimini, also bow & tonneau covers as they were on the boat already. You're right,it is one tough sucker. I had the dealer install the sea grass, fender clips, and AGM battery. I should have complained to Cobalt that I did not receive a $10,500 engine upgrade like some people! Lol

Dub

[Driller]

Great answers, thanks. Did not know the Bimini top was rated at 35 mph. We had very heavy winds yesterday and was thinking it looked quite stressed. Do any of you with more recent Cobalts have a fuel economy gauge? If yes, what speed or rpm does it usually max out at?

When I got my boat I looked back through the service records. Shortly after he got the boat the original owner took it in due to stress cracks around the bimini mounts. The service records warned the owner of the 35 mph rating and that over speed caused the cracks. I've looked, but can find no indication of any stress cracks. The repair was done at no charge.

I thought it was in the owner's manual, but when I just checked it does not state a speed limit for the bimini. It only states not to tow with it up.

So, either the dealer had some info that's not in the manual, or he didn't want to continue repairs for free just because the owner was driving around at 55 mph with the bimini shaking like a leaf.

[Southernboatman]

I'll post some perf #s next time out so I don't remember 3200rpm cruising at 40kts on 3gph. Mine is more like 3600rpm and 23kts at 7.9gph or close to that. Best economy is around 3000-3200 rpm on the vp380 if I recall correctly. Bimini is sturdy but I read a limit or statement to restrict speed to ?? but could not find in my manual flipping through it. WOT is reserved for when another boat thinks they are going to effect a pass, or just any other time you want to. But especially for those times when you can almost certainly not be passed unless you choose to be.

[Big Block Power]

I like this binimi because it's only attached to the tower. Very sturdy as well.But it does not give much coverage to the rest of the boat. But when it's not even 80 most of the time it's not up unless I'm trying to keep the carpet cool.

[Tuscany]

We've had our Bimini up two out of the three time that we've taken it out. That's two times more than I ever opened it up from the 13 years we owned the Chaparral. My wife and kids would never open it if it were up to them.
We get pretty good coverage, but unless its 100% humidity, I would rather enjoy the sun.

[Driller]

Mine has is a Cobalt also with the the ridge turnbuckles up front. Still the dealer issued the warning to the previous owner.

Mine is rock solid and has no flap at speed.

[jhnmdahl]

3000-3500 rpm is a sweet spot for a lot of boat engines, from a wear and a MPG perspective. Cobaltordie's post looks spot-on to me, and is the main reason I put a V8-225 in the back of my 210 instead of a smaller (or higher HP) engine. It seems like the recent trend is to use variable valve timing and other tricks to get more HP out of a smaller block and less displacement, which is great for fuel economy but less so for wear.

As for the bimini, ours is the kind that mounts to the wakeboard arch, and it buffets a little bit underway but is pretty well aligned with the boat's travel so doesn't introduce a ton of drag (at least relative to plowing through the water).

John