bman440440
New member
I have a 1990 32' Luhrs with twin 454's and I want to know what is the best way to run the engines... Should I run them at 3000-3200 RPM's for cruising or should I run them at 3400-3500?
The reason I ask this is because my thoughts are lower RPM's are better but when I run at 3000-3200 I get about .8 to .9 NMPG at 18-19 knots but when I run them at 3350-3450 I get 1.1 to 1.2 NMPG at 22-23 knots, so my thought is that the engines are not working as hard at the higher RPM's and evident by the increase in fuel economy. Is this a correct assumption?
I don't want to unduly over work the engines that is why I'm trying to find out the best RPM's to cruise them... FYI speed is measured by GPS and fuel consumption by properly calibrated flowscan. Also at WOT I get 4150 RPM's and 28.5 knots fully loaded.
Thanks for any help!!
The reason I ask this is because my thoughts are lower RPM's are better but when I run at 3000-3200 I get about .8 to .9 NMPG at 18-19 knots but when I run them at 3350-3450 I get 1.1 to 1.2 NMPG at 22-23 knots, so my thought is that the engines are not working as hard at the higher RPM's and evident by the increase in fuel economy. Is this a correct assumption?
I don't want to unduly over work the engines that is why I'm trying to find out the best RPM's to cruise them... FYI speed is measured by GPS and fuel consumption by properly calibrated flowscan. Also at WOT I get 4150 RPM's and 28.5 knots fully loaded.
Thanks for any help!!