35mpg? What am I doing wrong?

[jtanguay]

3800 rpm on the highway.... you're lucky you're getting 38 mpg  :lol:

[shwartzbewithyou]

You may be throwing in more air than the required amount of fuel, this would cause you to lean into the pedal a bit more but not really use the extra power as efficiently so you may be throwing away your fuel.

Sorry you're tired, but that makes no sense.  Less fuel to air will burn more completely and so in an underfueled state one will normally achieve better fuel economy.
Andrew

Do you know that for a fact though?  I would say that their's a good chance that it's all related.  I'm not just saying flat out that less fuel will equal worse mileage.  I'm saying less fuel could possibly be creating a very lean mixture.  A very lean mixture can be creating a very HOT running temp.  A very hot running temp or exhaust temp can be creating a very hot turbo (I can't remember if he said it was a turbo).  A very hot turbo can be increasing the air intake temp.  This means the air that the engine is pulling in is probably being heated.  Hot air intake causes poor HP.  Poor horsepower creates the feeling that you need more pedal, more pedal creates more fuel usage and then we start all over again at the beginning.  Think of a snowball rolling down the hill.  The more you give it the worse it gets.

[jtanguay]

You may be throwing in more air than the required amount of fuel, this would cause you to lean into the pedal a bit more but not really use the extra power as efficiently so you may be throwing away your fuel.

Sorry you're tired, but that makes no sense.  Less fuel to air will burn more completely and so in an underfueled state one will normally achieve better fuel economy.
Andrew

Do you know that for a fact though?  I would say that their's a good chance that it's all related.  I'm not just saying flat out that less fuel will equal worse mileage.  I'm saying less fuel could possibly be creating a very lean mixture.  A very lean mixture can be creating a very HOT running temp.  A very hot running temp or exhaust temp can be creating a very hot turbo (I can't remember if he said it was a turbo).  A very hot turbo can be increasing the air intake temp.  This means the air that the engine is pulling in is probably being heated.  Hot air intake causes poor HP.  Poor horsepower creates the feeling that you need more pedal, more pedal creates more fuel usage and then we start all over again at the beginning.  Think of a snowball rolling down the hill.  The more you give it the worse it gets.

Diesel = no lean.  This is basically how an eco diesel works.  Exhaust gases spin the compressor, and force air down the engines throat to burn the fuel more completely.  Nothing adds more fuel, so the turbo is more of a restriction and pollution control device than anything.  The only way that this reduces power, is that the turbo creates back pressure.  Of course the car will smoke much much much less, and maybe burn that extra bit of fuel, it will still be less powerful than an N/A at low rpm.  Only when the turbo is spooled will you see better economy.