Where to start?

[skinny]

OK, I have read pretty much the past years worth of posts now. I see that the programmer of choice appears to be the XCal III / Livewire, and that the "Best Bang for your Buck" consensus appears to be removing the muffler/cat. Another common "first mod" appears to be gauges.

My truck (07 6.0L F350 CC SB 4x4 auto w/ 3.73) is used mostly for road trips right now, mostly highway miles, hauling two snowmobiles on a deck in the winter. In a couple months it will become our daily driver, along with possibly hauling a 7500 lb travel trailer on the weekends.

According to the onboard computer, I got 6.1 km/L (14.4 mpg) on my last road trip the other day. That was setting the cruise at 1500 rpm, didn't pass anyone, easing up to speed, and off the gas and coasting well before any braking areas, and no wind to speak of. In the past, I have seen as high as 7.4 km/L (17-18 mpg) under pretty much the same conditions.

So, the usual question. Which mod will have the most effect on bringing my fuel economy to a more respectable level? I like the idea of the XCal's multiple tunes based on what the truck is being used for at the time, and I am not worried about the emmissions issue of losing the kitty. My dealer told me I could put a programmer on it without warranty issues (as long as I didn't use a "super hot" tune), but I didn't ask about the exhaust mods.

And finally, is the gauge install just a safety precaution prior to the other mods? If I am not messing with the tunes at all, do I really need to know the info that the gauges will tell me?

Thanks in advance...

 

[DIESEL97]

My dealer told me I could put a programmer on it without warranty issues (as long as I didn't use a "super hot" tune), but I didn't ask about the exhaust mods.

Thanks in advance...

So in other words he is telling you not to run a hot tune so you dont blow your head gaskets,but what happens when you blow them on a less hot tune?Is he still gonna fix it under warrenty?I think not.

 

[Maxtor]

14.4 mpg seems very low. 17-18 seems more normal at 1500 rpm. Why one truck will get 14 mpg and another will get 18 mpg stumps me, unless it is the drivers style that makes the difference.

I would get the dealership to put that in writing about not voiding the warranty.
I have had one dealership tell me one thing and then lie about it later. Years ago, before some of you were born, my wife ordered a 1965 Chevy Malibu ss 327 4spd from the factory. The engine got tired and we got a price for a 350ci 350 hp small block from a dealership. The engine came in and it was not the engine ordered. They tried to sell us the 250 hp engine for the price of the 350 hp engine. When I confronted the sales manager "who was directly involved with the sale" , he said "did you get this deal in writing" ?
Boy was I mad... I went straight to the owner, and this sales manager ran past me and said,,, " lets work this out". He sold my wife the 250 hp engine at the 250 hp price. That was the last chevy this family owned.

 

[skinny]

14.4 mpg seems very low. 17-18 seems more normal at 1500 rpm. Why one truck will get 14 mpg and another will get 18 mpg stumps me, unless it is the drivers style that makes the difference.

I would get the dealership to put that in writing about not voiding the warranty.
I have had one dealership tell me one thing and then lie about it later. Years ago, before some of you were born, my wife ordered a 1965 Chevy Malibu ss 327 4spd from the factory. The engine got tired and we got a price for a 350ci 350 hp small block from a dealership. The engine came in and it was not the engine ordered. They tried to sell us the 250 hp engine for the price of the 350 hp engine. When I confronted the sales manager "who was directly involved with the sale" , he said "did you get this deal in writing" ?
Boy was I mad... I went straight to the owner, and this sales manager ran past me and said,,, " lets work this out". He sold my wife the 250 hp engine at the 250 hp price. That was the last chevy this family owned.

This is a small town dealer, and they REALLY have bent overbackwards for me both in selling me this truck, and trying to sell me a replacement for our car. Service from them has been pretty good so far, and the owner (who was involved in the dealing on both vehicles) has also been in on the discussions about my mileage issue. I have to take the truck back so they can do some more testing on it, and I plan on asking about the exhaust then, and will probably also ask about getting some of this in writing.

Oh, and during discussions, the owner tells me that he was getting 14-15 mpg pulling a 10,500 lb 5th wheel with the identical truck, and he personally knows of several other guys running consistant +20 mpg on the same thing, all bone stock. Not making me feel real good about my truck.

 

[95_stroker]

How many miles on the truck now? If you arent putting a ton of miles on it it may not be completely broke in yet, however you should be pretty well broke in if you are past 25,000 miles.

The gauges are simply a safety precaution once you begin adding additional fuel beyond stock programming. If your not fooling around with the fuel you really dont need them. The stock PCM programming will take care of defuleing if needed.

As far as mileage is concerned, do yourself a favor and order your SCT with a custom burn on it for econo mode and your mileage should show it.

 

[skinny]

I am only at 22,000 km's (13500 miles), so I guess it's not quite broken in.

I would definitely be looking at custom tunes for the SCT, is there a good Canadian shop anyone on here can recommend? What are the best US shops for custom tunes?

While I have no issues with removing the emissions aspect of the exhaust, I don't want to make it overly loud. My neighbors like me right now, and I want to keep it that way. Does removing the cat and muffler add a ton of sound, or just when its WOT? What about changing to 4", 5", etc, does that make it a lot louder, or just change the tone?

Thanks for the replies so far.

 

[ckamp52]

yes you are not completely brokeen in yet and you will or should see better mileage in the future. as for exhaust if you just remove the cat it will help perfomance without changin the tune to much prolly just more whistle i have a 4" turbo back with a flow thru muffler and it is still not loud as my 7.3 is it just whistles a lot no complaints just compliments and peole thinkin i have a lot of stuff done to my truck and i have a quadzilla xzt module which is for mileage before they swapped from the old diesel to low sulphur i was gettin 20mpg and workin on better as i was at about 20k and it was still increasing now i get about 17 whether i drive 65 or 80 but when im towing i still get decent mileage never really checked on a heavy load as it wasnt ever really far. but i am lookin at gettin a xcal so if i choose i can run hot tunes. as for the dealer i have used the same one throughout my trucks and they never really cared if i had tunes on my truck i know the owner personally but i never told the service guys that and they have never questioned my trucks so havent had to pl;ay the i know the dealer card just an honest dealer so just do a few mild mods such as an exhaust and economy tune and u should be fine im happy with the performance of my quadzilla chip bhut as always i always want morebut that chp only runs like $250 u.s. so cant beat it if you dont need to change tunes ive have it on my truck since abnout 6k miles and im almost to 90k with no problems