What is the differnce between an '04.5 & later 5.9s? I know that the G56 replaced the NV5600 (in '05?), but what else? Do the '05s & later have an EGR? What about mpg (I don't want to start a war). Alot of people say that the '04.5 gets worse than the '04 & earlier, but I don't agree w/ that.

 

Only thing i see that i dont like. is my TST doesent work on my 07 didnt work on my 06 worked great on my 03-05 Dont Figure.
Fuel i cant say if stock none did good till they had at least 20K on them.
If my 05 could have been a MAGA-CAB i would have kept it!

 

Most of the 04.5's still had the lift pump on the fuel filter.
The 05 and later models have in-tank lift pumps.
Auto transmission programming is different.
06 model trucks have a more powerful ECM.
06 trucks with auto can use an exhaust brake.
06 trucks have a TIPM, total integrated power module, instead of seperate fuses.

My 06 gets better fuel mileage than my previous 05 and 99.

 

Are the 07's the same as the 06's?

 

What about the EGR? What about milage - does the '04.5 get better or worse than the '05? the '06?

 

None of the 5.9's ahve an EGR. Fuel millage is very subjective, my 04.5 got as good as actual 21.5 and when traded got as little as 15 highway empty. My 07 5.9 started out at 18 mpg, my 04.5 started out at 14. I do like the tranny (same tranny but more electronically controlled on the 07) shift and options on the 07 better than the 04.5. Everything fromn 04.5 on up has a catalitic converter but very non restrictive per many reports. They all also have the 4" exhaust fully back. My guess is the 04's may ahve gotten slightly better fuel millage, the 04.5 -07 still get good millage. Where else cah you drive a 7000lb truck even 4x4 and expect 17-20 mpg on the highway? I'm happy. My daughters 04 4x4 duelly gets 17 mpg empty highway running 75 mph so it's no slouch also. (they made a 34 hour trip from Seattle Washington to Jackson Mi due to a family death last year and did it getting 17 MPG with an empty truck and 3 drivers and probably did much higher mph that 75 if truch be told).

I don't think there is really much difference other than minor things for each year but like I said I really like the transmission differences.....shift points etc.

 

I had a 04 555 engine and I would say the Fuel MPG is the same as my 06. Stock power is way better on the 06.
On the 05 models if it has a NV 5600 it will have a intercooler with plastic sides. Unless already replaced. If it came with the G56 it will have a all metal intercooler.