2501 owner here. Twin Yammie I-4 200's. Fly by wire - I agree they are amazing to work with instead of cables. Here are my numbers. I run stainless 4 blade props 18 1/4" x 15" pitch (I think). No bottom paint.
Loaded heavy for offshore day and reasonable seas - 3500 rpm; 25 mph; 2.1mpg - 4000 rpm 29 mph; 1.9 mpg - 4500 rpm 35 mph; 1.8 mpg - WOT 5800rpm 45 mph; 1.3 mpg. FWIW...on my offshore trolling days I ALWAYS average 2.0 mpg out, trolling, and back. 140 mile days I'll use 70 gallons almost to the drop. Easy to figure gas for the day that way. With 156 gallon tank, I'll use half tank roughly. Plenty to spare.
Family days (loaded moderately and decent seas/smooth seas) - 3500 rpm; 27 mph; 2.4 mpg - 4000 rpm; 31 mph; 2.1 mpg - 4500 rpm; 37 mph; 1.9 mpg; WOT 5900 rpm; 48 mph; 1.4 mpg
I propped down my motors from factory 3 bladed because I wanted to turn a little higher rpms and take advantage of my motors' torque curves. It's a new boat. Yes, lower top speed and I lost about 0.1 mpg but easy on plane, easier staying on plane, easier to keep plane in rough seas while going slower, etc. Much more stern lift. I rarely use my trim tabs unless I'm really into a head sea. So, your props make a huge difference depending on what motor/motors you run on that hull.
I personally would never run a single engine on this hull unless it was maybe Yammie's new 425. Anything less and I would not think it would have reserve power to get you home in dicey conditions. I know there are a ton of 2501's out there with twin 150's and I'm sure that is (marginally) ok for this hull if propped right. However, Too many times I've been out and needed some extra oomph to get through a heavy sea to stay on plane and not have to baby the throttle all the way back in 50 miles. Plus, 2 engines...redundancy....safety....yada yada. I do think the 200's with the V6 configuration would be better for this hull with more torque. Staying on plane in heavy seas is sometimes troublesome since the hull will beat you up at anything more than about 18-20 kts if you're fighting choppy 3-4+ ft seas. Must slow way down and keeping on plane at rpms lower than 3300 is sometimes tough. The torque curve starts a bit higher.....Anyway, with the 4 blade props I've largely solved that and it's so much better in those conditions.
Bottom line, it's a great hull! Tons of space and drifting/anchoring/trolling there are few finer boats. Love ours but mind your throttle in 3-4+ ft choppy seas or it'll beat you up a bit. Parkers are very seaworthy and simple safe boats but speed demons they are not.
