I know cat back exhaust and K+N are basic things allot of people do. What are real mods performed by actual users (Not parts website data) on 6.0L trucks. Mine is a 6.0L 2500 series Yukon XL 4x4. Good and Bad results are welcome, just want to make sure I put good money at good parts if it seems worth it. Happy with the truck but always open to mods if they are worth it.

Thanks in advance.

 

Well therein lies the problem...
Do you want performance OR mpg, because you can't have both...
For the most part, vehicles, as of late come from the manufacture designed to get the best mpg you can get within economical reason...
Can you get better mpg? yes, but what are you willing to pay up front, and how long are you willing to keep the vehicle to get the payoff...

Getting performance is easier because you sacrificial fuel efficiency for that power, speed, torque...

Good driving habits and keeping your load as lite as possible will get the best mpg...some mods though, can give you better performance when you need it without affecting overall mpg, tunes ( Black Bear seems to be the most talked about) and as you mentioned making it easier for the engine to breath.. It has been my impression from being on this forum thought, that those that do the mods to the intake and exhaust get lower mpg because now they can't keep their foot off the accelerator..

 

There are mods to exhaust and intake that on any engine increase power and mileage. I know when you hit certain levels you tilt one way or the other. I was hoping to hear from real life experiences prior to plunking down the cash. I am sure there are some slightly modified 6.0L's out there, hope to hear about them. Air box's, Cat Back or other simple mods such as tuners or othe ideas.

I like your comment about keeping your foot out of it. When I checked my MPG I was easy on it, although I can see with a sweet sound you may want to hear it more!

 

LOL! yep the new sound of power does draw you in deeper to the pedal

I'd figure at an average of 17 mpg at $3.50 a gallon that comes out to about .21¢ a mile. So divide the cost of your "mods" by .21¢ and that would be your mileage you would need to drive assuming an improvement of 1 mpg to pay off or break even on the mods...
More realistically though any gains would be in the 1/4 of a mile improvement or less so quadrupling the mileage need at a consistent improvement to pay for the mods before even making gains... conceivably you may need to drive 16k miles just to pay off the mods of say $800 and 32k miles or more to get your money back...

Don't get wrong , not trying to shoot down any improvements, its more about other readers understanding that you have to spend real money to get real gains, and it takes a while to just get that money back, often times longer then some folks own the vehicle

 

Most external mods e.g. CAI, headers, cat-back exhaust only improve power/mpg if you make applicable internal engine mods e.g. hi-flow heads, valves, & intake, cam, higher CR, and ECM tunes.

As in2pro mentioned, a Blackbear tune is probably the most bang for the buck.

 

I have been using a fuel enhancer called XP3 in my 2007 Impala LTZ. Although it is only supposed to get 26 mpg highway when new, I got 28.9 mpg last week when I drove from Minneapolis to Chicago last week. During the trip, the car turned over 100,000 miles. Not only did the mpg go up, but the car also performs much better.

product information can be found here:

FuelDirect

 

I would agree that the best bang for the buck would be the tuner, or find some one that can remap the ECM, I had my ECM remapped and I gained power and milage. The GM mechanic that remapped my ECM said I would have a horse power gain of about 30 horse power as the stock 6 liter doesn't go full throttle from the factor, and I deffinately noticed the difference as I pull a 34 foot holiday trailer, and my milage went up as well both loaded and unloaded

 

As an eternal skeptic, I'll buy it when I see some dyno sheets.

Did he remove any or all of the torque management?

 

That is a really important question to ask BEFORE a tune is added.. because if it does, you have just voided any and all drive-train warranty...forever...

 

If I remember correctly it is set that it would go full power at 50 percent torque load and 3200 rpm, I really notice it start to pull harder when it hits that 3200 rpm, he also removed the speed limiter as well, so my truck is not governed anymore to 160 kmh. As for the warranty, the truck is over the milage for warranty so I am not to worried about it