I was thinking the other day on why the 03-04s get better MPG than the 4.5+. The on the 4.5+ they have CATs & for what I can tell the 03-04s don't, other than some small stuff like injectors & stock programming.

I know that their's a lot of talk about the 3rd injector event. I don't think that is the major cause. Both "years" have it. I think it might be with the CATs. I've noticed on my 05 that before the engine gets up to temp that my EGTs are higher than when it's warm. I was figuring that to do that they would a) have to inject more fuel or b) changed the timing to fire later [well c) both].

So here's the question: does anyone know how to deactive this feature?

It would be really interesting to see if this would increase mileage.

 

The third injection even has been proven to be more of an advantage then a dissadvantage.

There's no way to dissable it and have it be effective.

Back in 04 everyone was griping about it but it has since been proven effective.

I have an 03 and average 14-16 mpg.

I dont tow but I do live at 4000' and have 35's and like to GET IT on occasion and drive between 70-85mph. The rpm are pretty low with 3.73's and 35's.

I can squeeze 18-19 mpg under (2Krpm) and no more then 1/4 throttle but its hard to drive like that where I live.

I think better mpg is more about how you drive then the 3 injection event.

I'd much rather have a newer truck then an 03 that gets 1.5 mpg better.

Its hard to get honest answers from people about their MPG.

I'm an honest guy and im not afraid to tell people I get 14-16mpg

 

i can get 200 miles to a gallon...............of whiskey kiddin (kids don't drink n drive) hey slow I lived in Corona back in the mid 80s

 

From what I've seen and read, the 12 valves get a little better than the 24 valves, which get slightly better than the first Common Rail 3rd gens, and they get a bit better than the later 600's, which seem to get better than the 6.7...

Mine (HO 3.73's stick) can get up to 20 in all highway driving around 65 mph, but it goes down quickly at higher speeds...

 

I get 30 going to work- (no, really I do!) it's all down hill. Then 16 coming back-- overall about 22-23 driving like granny... It is about 21 all flatland. But heck, then I want to always have my foot into it and you all know what happens then..

 

SlowSixSpeed,,, you live in Corona? 4000ft? Where? BTW, I have an 03 with a cat. Looks like a war head down there.

 

03-04 CA emissions engines have CATs. The CATs that are in the CTD's are actually fairly non-restrictive. Losses to be had by their presence are quite low/negligible. The biggest change that seems to happen is the sound of the exhaust.

 

looking at one, you'd never think it was non-restrictive. I held one up to the sun in the middle of summer and couldn't see a spec of light through it!