sorry. SC 3815

 

Must be more stop than go to average only 10? Unless there was something about the 03 hemi that made it drink more than mine does. I avg in the low to mid teens around town and mixed driving and high teens on the highway. If you dont have any history to know if/when the plugs were last done, definitely do those. A little bit of a pain to do it yourself but read up and be patient and its doable and much cheaper than paying someone else. Dont go nuts with fancy plugs either. Hemi likes good old fashioned single tip copper core plugs. But it requires 16 of them, not 8. Might be good to change the wires as well.

Unless i missed it, you didnt say how many miles on the odo. May want to consider servicing tranny and diffs too. Save all the toys until you are sure its in good mechanical order.

Agree with a tuner first. Find out where you are at stock with a tune and it will make you appreciate the gains any mods give you later.

And as hinted in other posts, its probably a waste of time to ask which exhaust is better, etc. you may get some ideas to consider but i doubt you will find a consensus on those topics.

 

Is the pwr wire mod only for the hemi? Have an 03' 360.

What does the pwr wire do?

 

04hemigreg my mpg given was me relying on the overhead console,im going to watch what i do on the next couple of visits to the pump,and figure exactly what im getting.as far as the mileage she has 92334.

i think im going to have a tune up done and get the sc tuner,after that not sure whats next at this point lol

the previous owner putting everything up 20%..can anyone explain that for me?

 

Just keep in mind that allot of factors go into your upgrades. Switching from single to dual exhaust will benefit sound, but may not help out so much with fuel economy, this will depend on the setup you choose. Straight pipes sound great and give more horsepower, leaving a minimum mpg gain, if you notice any at all. X pipes will give more tourqe but other than sound, you might notice a decrease in mileage. A simple cat back setup with the wide pipe going into a highflow dual outlet muffler will give a good sound, not affect power much at all, but you'll actually see a rise in mpg. But this again will depend on configuration and parts selections.

A cold air intake has to be a careful buy. two things to remember, 1. If the heat from the engine is not seperated, your sucking hot air, thus the intake may not give desired power/fuel economy savings. 2. Placement is key, put it to close to or to far away from the right spot and you could end up with an idle speed issue where the intake isnt getting enough air to suck on when not moving, or just the opposite, You could be couphing down the highway at 70mph at 3200rpm's sucking fuel down like a late 60's bigblock muscle car and getting the power of what would compare to that of a scooter winding out at full bore.

 

He probably either figured on his own that he was actually getting 20% better than the computer was reporting, or someone gave him the idea that it's some sort of rule of thumb, or it just helped him feel better about seeing low numbers on there. I keep mine set on the temp, unless I'm running low on gas, then I display the range until I can make it to a gas pump. Best thing is to do what you said - just figure your mileage the old fashioned way. But my computer rarely showed less than 10mpg even when I was towing a 6 to 7k RV load down the highway.

So, sounds like you are going to take it to someone to do a tune up? Hope your wallet is deep. Can save a lot in labor costs if you are willing and able to wrench your own truck. And this forum will provide lots of info that will help you do things you might not have thought you could/would do on your own.

Throwing mods at it isn't going to magically and significantly increase your mpg unless you just get lucky. Best thing to do for exhaust is pick one out that you like the look and sound of. Once you get into something like a CAI and beyond under the hood, and a good tuner, you will be able to tweak it a bit. You may find that the tuner is the best tool for helping with mpg. Another good reason to start there. Sadly, I was never able to get one to work with my truck (long story).

 

Although my truck has the 3.7ltr. V6, when I got it...at 46,000 just like my 04 Dakota, It had Spark issues at 60,000 miles and started guzzling gas. The stock NGK plugs were burnt to hell (both trucks do 20,000 miles yearly on the highway). Swap to a mild Bosch double platinum plug restored power.

I then decided the 15.8 MPG average could be allot better than it was. I did some research on what would help a truck that enters an on-ramp everyday at a 23% upgrade, not fight like a smoker to reach 55 miles an hour by the end of the on-ramp. My truck was struggling to hit 45mph! My MPG average was taken at the pump divided by total miles driven. At the time i was getting about 23 gallons to 360 mpt.

I researched Jet Chips and people were raving how it freed up the RPM's (and it did free them up!!!) And it provided better torque response at 3000 RPM's. I didn't notice much on fuel, I think I got about 10 to 15 Mpt out of that one upgrade. Then I went for a cold air intake (I think us v-6 owners have a more leeway on how to position the piping since we have about a foot of space between the radiator and the engine). The CAI was simple to install and after building a divider for it gave me a big difference in power gains and fuel savings per tank seemed to double as much as i would say 25 to 30 miles a tank! Then the exhaust, nothing special, A flowmaster 44 dual out gave me a nice sound with maybe another 3-5 mpt and no performance gain what so ever.

My weekly driver sits on the highway approximately 350 miles a week and roughly 50 miles around town. If i push it to the empty mark i read roughly
415 miles and fill about 24 gallons of fuel in my tank, which is allot better with a tank average of 17.3MPG. Research and listen to the recommendation's and warning's. They will help out in both power and fuel.

 

not the onboard reading,he said he hooked up to the plug under the wheel and unlocked something and raised everything up across the board?

thanks to you guys that have been chiming in!

 

is it also true that if you drill some holes in the bottom of the stock air intake that it can give you the same effect as a cai? doesn't sound right to me.

 

Wouldnt make any difference IMO

Sounds like a tuner was used but no way to come close to verifying 20% without doing dyno runs before and after and even then, no tuner out there says anything about boosting anything 20%