You have a 22 gallon tank, dodges typically have ~5 gallons left when the low fuel light comes on. Idiots would run out of fuel all the time if it came on when it was nearly empty. Guages are never an accurate way to measure fuel level, just a rough approximation.

 

The only real problem with this method is how hard it is on the fuel pump, unless you like spending $300 every time it burns out because the pump over heated from lack of fuel. (the gas acts as a cooling agent for the pump).

 

I saw a show on this very idea about using fuel to cool the pump (I think it was the creepy kid and old chevy guy on the powerblock). Let me just say that the fuel pump is ALWAYS submerged in fuel inside the fuel damper plastic thingy. While I have not personally tested the run out theory, nor the fuel mileage loss from weight of fuel versus fuel pump replacement test, I will say that it would not be concerning to lose a $50 fuel pump every 100,000 miles from overheating, versus the mileage loss from an extra 50-100 lbs of fuel in the tank at most times. I say send the idea to mythbuster's and let them do a objective assessment. I will also publicly apologize to the entire forum if they say it is plausible.

 

I just did the gas mileage calculation for the second time and got 19 miles per gallon. I'm pretty happy with that since this tank was a combination of city and highway driving. I have the 22 gallon tank. The first calculated tank was 18 mpg but that was before I had determined, thanks to this forum, that I had a 22 gal. not a 15 tank. She has 82,226 miles on a 3.9l Automatic trans 4x4. Not bad I would say.

 

You don't have to run it completely empty before you can check your mileage. I'm obsessed with my mileage, and usually fill my tank before if gets below the full line on the gauge ( usually about 50 miles). As long as you divide the number of miles you drove by the number of gallons you put in. You will have a good average mpg. I was having some problems with my truck and I replaced the o2 sensor, tps, iac, crankcase breather, and PCV valve, my mileage jumped from 13, 14 up to 20 mpg, then leveled off at 17, 18. I took off my performance chip and I'm at 15- 16 mpg average. It was a stage 2 Jet. I now feel like someone kicked a leg out from under the truck. I've heard that Jet performance sucks, but damn it made my truck fun! And more mpgs! Oh and I think the jackrabbit starts are better than taking your sweet time to get up to speed. I think there is little to no diff. If anything I get better mileage with the jackrabbit starts. haha The best thing you can do for mileage is buy a HONDA civic, or crx! I've had several, and have gotten up to 50 mpg with them! Even the poorly running ones got at least 30. I had a turbo civic pushing 380 horsepower, and I still pulled 27-30 mpgs. And I drove it everywhere at 5k rpms haha Almost forgot. High quality synthetic engine oil (royal purple) and transmission fluid will gain you 1 to 2 mpg's. And your truck will love you for it....

 

I am assuming you guys that are getting 19MPG have the V6.

What do you guys with the V8 get at the top end of mileage. I am at 13MPG now. I dont have an O2 sensor, will it jump up if I get one to put back on?

Also regarding the O2 sensor on a V8, there is just one O2 sensor that goes before the cat right? So if I have straight pipes and just have it in there about the place that it was, it should read correctly...correct?

 

It is best to have a properly working O2 sensor.
95-down 1 O2 pre cat. 96-up 2 O2 1 pre and 1 post cat.

 

Well dang. My truck is a 96. So what your saying is I either need to get a computer from a 95 and use one O2 sensor which would be a pain in the butt. Or I need to get another cat with 2 O2 sensors. Which probably isnt happening. Unless one of you guys think I can get 19MPG with a cat and both O2 sensors. And still get a decent tone with my glasspack.

 

The 96 is OBDII which is a different system then previous years, so a 95 computer won't work.

You can get an O2 bypass kit some use a module that fakes the O2 sensor.

Just varrify you have another plug in for the 2nd O2 sensor. If so then go to a muffler shop and have them weld in an O2 sensor bung after the cat.

There are high performance cats you can buy.

 

I always check my mileage, it lets me know if anything is changing in my engine. I just fill up the tank as well as possible and reset the trip meter each time, almost every time I get the same thing. 14.6ish
anyway,
Take a look at your air intake, I was having an issue with crummy gas mileage, and after taking some sea-foam that was recommended by "crazy 4x4" my mileage has gotten better. There is a notable increase in power too, in fact, it keeps getting better, I am thinking about hitting it again with that stuff.

Does she feel like she is an old lady on a cheese diet? a little backed up?

My gas mileage jumped on me from 14-17, freaky thing. and I had a CEL that was for the Imap. SO I started to look at intake plugging and hiding vacum leaks.

Good luck