I suppose I doomed to spend my life enlightening noobs.
Us fat guys go through life thinking there will be a magic pill we can take and we'll be as cut as Olympic athletes without starving and working out 26 hours a day for decades. Alas, I haven't found one yet.
The great belief that a chip or exhaust pipe will get you 30 MPG
is exactly the same - a version of the great cosmic search for a free Lunch. I can see why there is a lot of blind faith in chips. They greatly improve acceleration and speed with minimal work and outlay. If that's all you are after, they deliver.
But they don't help MPG
. I run a chip burned by one of the more knowledgeable dudes in the Nation and it gains me maybe 0.6 MPG
Over the last nine years I've tried everything. Big exhaust, high-flow air filters, synthetic oil, etc. A 203 degree stat helps a little (about 0.5 MPG
) but beyond that what works is limited to better aerodynamics and numerically lower gearing.
Those two things are why I get 24-27 MPG
and you don't.
Aero is obvious to anybody who has ever stuck his hand out the window.
Gearing works because it reduces engine speed at a given road speed. Less engine speed means less engine frictional HP. Engine frictional HP is why you never, ever want to exceed 2000 RPM. Above that, engine frictional HP goes up exponentially with RPM. Below that, engine frictional HP goes down proportional to RPM. Below 2000 HP frictional torque is fairly constant but above 2000 RPM gas flow through the engine is congested by turbulent flow.
I go down the highway at 70 MPH turning 1700 RPM. If I put a GV on, I'll reduce RPM to maybe 1300 RPM, so my engine frictional HP will be 65% of.that of a guy turning 2000 RPM.