Let's talk about fuel economy.

[RdWing]

Hi guys.
I'm having a huge issue with my car.

Just rolled over 135k btw. The car has been in my family since new and has been well maintained.

I've been averaging about 13mpg +-1 over the last 4k miles i've put on the car (1.5months). I calculate using a GPS that runs when the car is on and always fill the tank and calculate mpg. miles/gallons to fill. Only drive city except for a daily 10 mile each way freeway commute. I do deliveries, about 100miles a day.

I've changed air filter, oil (mob1 5w/30), transmission fluid (4x), new tires(225/50/16)/oemrims + balance + alignment, spark plugs, & cleaned injectors with BG44k + much techron concentrate, new pads all around and new rear rotors. Car does come up to temp quickly.

The car seems to be moody with acceleration sometimes according to my butt dyno, but this may just be in my head. I feel like it bogs (diesels) a little in 3rd and 4th especially under 2k, but I think this is normal. Sometimes it feels like it pulls stronger.

I tried octane booster once cause I thought it might be shitty gas causing the engine to pull timing but it didn't seem to make a difference. I always fill with 76 or chevron 91 octane. All gas here is 10% ethanol.

Some gas seems to just work better (again may just be in my head)

If anything the economy has gotten lower.
I plan on doing the fuel filter soon but the car does not show any signs of a clogged filter. (no hesitation or stumbling).

Idle is smooth.

My VSS is wonky and works sometimes. It doesnt seem to make a difference with economy. but i've heard it can sometimes cause the ECU to run rich.

Any ideas?

discuss.