A tachometer in a P-30

I'm almost 32 feet. Weight is 13580 fully loaded.

Gjac wrote:
I am surprised also that the newer 8.1's and V-10's don't do better than the older motors. Most seem to report 7-7.5 mpgs on on the newer MH's with 5 & 6 speed transmissions, while 8-8.5 mpg seems to be the norm for a 454 TBI with a 4 speed transmission for the same length MH. Maybe more HP uses more fuel? Weight of stuff inside more slide outs?

They are significantly more efficient, its just that they are installed in units that are much taller and about 8K lbs heavier. Most the old 454 are running in coaches that are 16K lbs on lower profile chassis. The 6 speed does not help mileage, but just optimizes engine speed for best use of available power. In high gear, the engine RPM is still nearly the same, regardless of if you have a 4 speed or a 6 speed. The difference is that when you ask for more power, it will shift sooner, so the engine is turning the optimum RPM for the needed power. You also have a lower first gear.