I'll have 250 miles when I'm at the 1/4 tank mark. I'm using something, not exactly sure what. My mechanic works at Toyota so he gave me some Toyota fuel system treatment stuff of sorts... Getting near my fill up mark, I'll calculate and post the results soon.

 

I have only gotten 17 mpg on a tank when I was running the **** out if it the whole tank. I'm talking running over 100mph(found out its limited to 130mph) and mostly flooring it on take off. City driving I get 22mpg and get 24mpg mixed, 26 to 27mpg for highway. That's for my 03 auto.

 

If I was running mine hard I'd probably get 150 miles to a tank.

 

Timing has been mentioned a few times here, can someone explain how the timing is supposed to behave? I've been searching the forum and all I've found is info regarding the 2 degree timing advance. What I'm interested in is the following...

• How the timing SHOULD behave in these cars while idling, accelerating, cruising, etc...
• What ranges are considered normal under these circumstances
• Whether a reading of negative timing is ever normal
• How base timing factors into everything (I assume this is just the timing starting point)

I just purchased a bluetooth OBD adapter and downloaded Torque Pro (free version so far but will purchase full version if needed) and want to check my timing and anything else that may shed light on declining MPG. I've played around with it a little just to make sure I can connect to the OBD adapter and see info in the app, so far so good.

 

Last fill up came in at 11.43L/100km! Still lots to be done though... Also curious to Uncle's questions.

 

I found in the FSM where it mentions stock timing of 15° +/- 5° BTDC when in P or N (not sure what BTDC means. Base Timing something or other?). The FSM doesn't make mention of what timing should be when actually driving.

 

I've determined that whatever issue is causing my gas mileage to decline effects city MPG way more than it affects highway MPG (If at all). I took a 135 mile drive last night for work and I started with 134 miles on my trip odometer. With my day-day driving I would have expected to need a fill-up between 250-270 miles. I arrived at my destination with the trip computer reading about 84 miles DTE.

I brought a can of BG44K with me that I'm going to put in the tank before I fill up for my drive home. Before any MPG decline I would get 300 miles to a full tank and my driving hasn't changed much.

 

I'm doing some highway testing to see how it affects mine as well. I'll post the results next fill-up.