I am running 87 octane. I wasnt aware of the need for 91. I'll try that on my next tank of gas.

 

O2 sensors can fail to operate properly without throwing codes. I believe they're supposed to, but that's not always the case.
It could be driving style, that has a huge impact on economy. When I don't lead-foot it around I can get about 15-16mpg on the highway, but when I drive "normally" my mileage goes down to 12.5, and the exhaust, K&N FIPK, Hypertech 93 octane tune haven't affected it at all.

 

 

o2 sensors play a very important roll in addition to many other sensors on our new technology engines. In my opinion, when trying to utilize fuel economy, drop the upgrades. Im sure the combination of the performance adders are causing your poor fuel economy, check your o2 sensor and cat as virused recommended.

 

I can't speak for the Jet stage 2 or whatever CAI and 70mm intake he's got, but I gained mileage at cruise when I went with the FIPK and Hypertech 93 octane tune.

Standing on the gas though my mileage went down.

 

yes, check the O2 sensor. if it is bad it will make the computer think the engine is running lean and dump more fuel.

 

11 to 13 is a typical mixed driving MPG number for a 4.7 Ram 4x4
based on added up and averaging what owners at this and other forums report.
For a second opinion go to the bottom of this review and read:

http://www.usatoday.com/money/perfi/...0-ram.htm#more

sample quote:
• How thirsty? Ratings for city/highway driving: V-6, manual: 15/21 miles per gallon; V-6, automatic: 15/20 mpg. 4.7 V-8, 4x2, manual or automatic: 14/19 mpg. 4x4 manual: 13/18 mpg; automatic: 13/17. 5.9 V-8, 4x2, automatic: 12/18; 4x4: 11/16.

Reality: 4.7 V-8, Quad Cab, 4x2, automatic got 13.1 mpg, according to the truck's computer, in 700 miles of driving: 475 on interstate, 225 on suburban roads. 4x4 version: 11.8 mpg in mainly suburban driving. All engines use regular-grade gas.
end quote
=======
If you really want to check to see if your truck's 4.7 engine is 'healthy'
do a gas station to gas station 'test run' of at least 100 miles
at a steady 60 mph on an interstate highway
on a day that there is no more than 7 mph of wind
and the temperature is between 50 and 75.
The hand calculated MPG should be at least 19 for a 4x4
and 21 MPG for a 4x2.
Knock off 2 MPG if big mudder style tires are on the truck.

 

Try this one. I also have an 02 Quad cab dak with the 4.7L. No mods that I know of(bought used). I get about 15 mpg but the fuel gauge light comes on at 200 miles almost like clockwork. I fill it up and can never cram more than 16-18 gallons. But this truck is supposed to have a 24 gallon tank. My guess and the guess of a mechanic I spoke to briefly was that the fuel level sender unit is bad. He also said that Dodge trucks were horrible with fuel level senders in the late 90's and early 2000's. Anyone else have a situation like this? Not to rob the post but thought I would mention it.

 

Yeah, thats a good question. You should definitly make a post about it.

 

proaly not a 24 gal tank..