i was reading old issue of diesel power mag ,they said you can dyno your truck and use the fuel burned per hour (i think that is what it was) to help select best hp setting to find better mpg .i dont have the article anymore and was wondering if it was true , and with the expence of dyno time is it worth it ! i ve never dynod anything so dont really know the cost,anyone heard of this? or is it just page filler! thanks

 

its call brake specific consumption of fuel still dont understand it but thats it

 

well iguess no one cares ok

 

I have heard of this years ago in my gas hotrod days. It does make a lot of since though. If you engine is making maximum torque this is the point where it is running the mose efficient and you are getting the most bang for the fuel ($$$). My truck seems to get the best milage when I keep the RPM's 1500-2500 in city driving and 2000-2200 on the Hwy. This range also happens to be the sweet spot for torque also. I get aroung 18.5-19 doing that anywhere else is about 16.5mpg. Thats my take on it. I think I read the artical too.

 

Back when I was bending throttles on big round motor airplanes, on a max endurance flight I would look into the charts and compute what the most nautical miles per pound of fuel settings were. This basically boils down to leaning the fuel mixture until output torque peaks (best power) then further leaning mixture for a 2% drop in output. While it would be almost impossible to bs the computer below best power, This point can be reached by running @ a constant 2000 (appx) rpm in high gear with a box on performance setting (leanest) with a good performance filter & ram air if possible. A free flow exhaust helps also. This is a close but rough approximation due to additional fueling available due to bombing & no way to lean mixture & monitor pure crankshaft output torque. just my 2 cents.....