I was throwing the idea around of having my ECU tuned. It’s a stock Mercruiser 7.4 mpi with a Bravo 3 drive. Engine runs great and is propped correctly. Question is, is it worth it? I was going to send it to Hardin. They say adds 15hp.

Sorry to say ...but you not even notice 15 HP.

Padraig

You will notice no performance gains but will have a lighter wallet.

15hp = maybe a 1 mph gain at WOT
Better off to get your props labbed

You can then say what the kids at my work say. It’s ‘Tuned.’ lol

I don't know about that. It's a lot of hassle and money for a big maybe in payoff. I've only been fortunate to have 1 set of labbed props deliver what was promised. And it was just a tune on them. Most over promise and under deliver. I believe it's never a net win for the customer unless it's a specific application i.e. racing. I have 9 sets on the shelf in all different configuration currently.
Controversial I know...
JMO