my MPG is pissing me off now

[zagarus]

OK so here's the situation.  My Mileage is going down the crapper it seems and i need to know why,  first ill mention what is done to my car in hopes that it will help out:

-K&N filter in un-swissed box
-Boost controller set to 17PSI
-MAx fuel on pump turned up a bit
-GTD nozzles in stock injectors (nothing rebuilt, same shimes, etc.)

thats it for the moment now i just filled up my car and fopr the last two times its been around 30mpg,   today i filled up 40litres and only got 526KM out of it.  I use additive everytime i fill up, fuel filter replaced every two oil changes, i also just had a new oil change with 15W-40.  Now i am totaly stumped why my milage is so bad so hopefully someone can enlighten me on the problem.

PS - my mechanic says the fuel pump sounds good, doesnt look like it leaks, although its possible i leak at the top of my fuel filter and possibly two of my injectors (they always seem wet around them)


Thanks for any help guys.

[burn_your_money]

you should definitely change your oil filter every oil change. There is a lot more soot and crap in diesels then gassers.

How many l/tank were you getting in the summer?

[foxracer1]

I filled the last tank up and the reciept said USLD. I got 34mpg  :x   I was driving about the same on that tank as everyone before that maybe less highway travel. That is compared to my 40mpg i was getting with my old white bunny same trans, more milage, very tired engine.

So i think that USLD sucks. I'm going talk to the local supplier about haveing Bio diesel brought to the house. hopefully it will be easier on my wallet.

[andy2]

I too believe that ULSD is most of the problem with generally any diesel engines poor MPG.

[zagarus]

last summer i was always averaging 38-39mpg around town, highway was 45-48mpg.  its been decresing ever since last july, i havent changed much to the engine since last year so its something going on on the inside that is making it get worse and worse.

[745 turbogreasel]

My Suburban MPG decreased form 18 to 15 just before my auto tranny went out :x   Maybe I"ll get 20 with the new one?

[jtanguay]

my car's mileage seems to be going up.  gtd nozzles with around 160 bar breaking pressure too.  did you get your injectors pop tested?

i'm averaging 650km per tank now.. used to be lucky to get 500km.  and that is basically always driven hard.  i find it hard to restrain myself  :lol: plus the fact that i must push the small engine real hard to keep up with some of that crazy rush hour traffic!!

[zagarus]

i honestly doubt my injectors were testes of any sort,  one reason why i changed shops. :evil:    but when i get a Giles pump this year i was planning on redoing the injectors.  give the system a nice refresher.

[craiggroombridge]

check the timing and for added lubricity add 2 cycle oil to the fuel it really works my dad's 6.2 gm gets 39 mpg with a 4spd trans

[Powjetta]

The next time you get back from a trip walk around feel the brakes on all four corners and make sure nothing is dragging.  Some times up north things can get stuck.