For the last 2 tankfulls, my fuel mileage seems to be dropping. For the last 15,000 miles (since the new tires), the truck has averaged 22mpg for my daily routine. 2 tanks ago, it figured up to 19.7 and this last one today scored 17.6, all hand calculated (the overhead still reads it's optimistic 24mpg or so). Nothing has changed. All filters and oil changed 3000 miles ago, same brand of fuel (different fuel stations), oil level fine, no rough idle, no white smoke, no dragging brakes, no CEL. The only stored code is - P0633 - SKIM Key Not Programmed in PCM.

It seems a little early in the season for winter fuel, and even if it was, it's never effected my average more that 2.5 mpg or so. I've use Power Service every fill-up for 4 years.... I'm left scratching my head. Any ideas????

 

I'm not very experienced with this but maybe try cleaning out your air intake. I hear it can help quite a bit sometimes. just an idea, not sure of much else though. I doubt it'd be the 'root' of your problem but it couldn't hurt I guess.

 

And clean your IAT/MAP sensor, brought mine back up.

 

OK, help me out. IAT/MAP sensor?

 

You may want to check where you are getting your fuel at. I have been going to the Mobil station by the highway (3 miles from the house) for almost three years now. This weekend after filling up saw a NEW sticker that explains the fuel from the pump is anywhere between B5 to B20 (5-20% biodiesel ). I have noticed the overhead a little lower than normal, my guess right now is 1-2 gpm less. The sticker was 1/2 black and 1/2 light blue. I know some on here love the stuff but for me it's my $ and truck and want no part of the bio-snot in my vehicle. It may have happened to you too.

 

Some have said that replacing the crank position sensor ($75??) will help. Don't have personal experience with it though...

 

MAP Maximum Absolute Pressure sensor: used for emission control

IAT Intake Air Temperature Sensor

 

OK. I'm guessing the MAP is on the driver's side top of the head that my Edge/Juice gets it's boost singal from and the IAT is the carbon bodied do-dad directly behind the air filter. Correct?

 

Geno's has an article concerning cleaning the sensor. http://www.dodgeram.org/tech/dsl/sensors/IAT/clean.htmMay not pertain to you. Mine is a combo MAP/AIT sensor located on top of the head held in by two torq screws.

 

I know you claim same fuel but fuel can differ from load to load even at the same station. Why so much power service by the way? IMO it has too many solvents to be used constantly. I think it's a great product for use as a cleaner once a month or so but every tank is overkill,just my .02

 

I have heard the oil companies are distiling the ULSD at the very top of range on cetane. Lighter more volitile fuel means cetane is higher, consequentlly heat engery in gallon is less. Have you also noticed that since crude is hovering at 100 a bbl you have seen relativelly little change in pump price. Those lying, money grubbing, PIA's don't care if they kill the american econony. As you can tell I'm using great restraint and don't want anyone to think dozerman is whizzed. I might have to tell how I really feel

 

My main reason for using the PowerService is to lubricate and guard against fuel system damage caused by this stinking ULSD the feds are pushing down our throats. 03 and early 04 trucks are lunching injectors for some reason and most people are pointing their fingers at ULSD.