IP 350 under power

Hello, I'm looking at a few 35 (ish) style cruising boats - I love the IP 350, but haven't had the opportunity to sail on one. As a seasoned "cruiser" I've found that so long as I can make 6 kts (under sail / power / or combined) I'm happy with my speed. I'm just happy to be on the water, so I'm not afraid to power sail in a light breeze. So my question is this - we sail in light wind frequently, how fast can the 350 "run" with the 38 hp yanmar - not top speed, but cruising RPM's, .75 -.80 % throttle?

Thanks in advance

Like you, we tend to have a minimum speed that's acceptable when trying to get somewhere. Ours is 5 k; yours is 6. Our 350 does not usually see 6 while sailing unless we have wind in the upper teens (which is PERFECT!). Under power (we have the 40 hp model), 6 is achievable at 80% throttle. We often achieve 5+ in winds of 10-15. BTW, we consider the 350 to be the perfect boat for coastal cruising for a middle aged couple.

Thanks for the reply!