6.2L (L9H) Owners - Get all your questions answered here

[bogeypro]

I'm averaging a steady 12.9 13.2 in city.. I got maybe at best 13.5 or so in my 06 silvy w/ 5.3, I'm glad i made the switch. Helps that I live fairly close to work to..

Yep, that is the mileage I am getting as well.

['01LS1]

Mine is the same as your signature with exception that it is ext. cab & stays right around 15.7-16.2. Has 15-16 hundred miles on it now. Just off of filling it up & running down a city street full of stop lights that avg will be right around 12 though.

[SilveradoX2]

My wife is getting about 14.7+/- driving mostly freeway during her commute. When I drive it (call it my Corvette), probably get 10-12 cuz I manually shift alot.

[SilveradoX2]

It has been awhile since I have posted on here, I made another change on mine by running true duel exhaust and removed the 3rd cat, ran both pipes thru H- pipe into 2 Magnaflows. Sounds unreal and big increase in low end torque.

Has anyone else done this and been happy with their results?

Who did the work and about how much it you don't mind sharing. Thanks for the post.

[txmuder]

SilveradoX2.......I took it to a performance muffler shop of Shepard & Parker in the North Houston area (Best Mufflers), all together including material I spent $470.00, (I already had 1 of the Magnaflow mufflers and reused it and bought 2nd one along with X-Pipe.

 

 

[SilveradoX2]

SilveradoX2.......I took it to a performance muffler shop of Shepard & Parker in the North Houston area (Best Mufflers), all together including material I spent $470.00, (I already had 1 of the Magnaflow mufflers and reused it and bought 2nd one along with X-Pipe.

 

 

Great info, thanks. I have a muffler shop in mind. Will get a quote based on your info and update here if I do it.

[SilveradoX2]

Thinking of trading the 2012 in for a like 2015 High Country edition for the direct injection, HP increase and I really like the new cab. Greatly respect the persons here for what they've done, would like your input. Point me to another thread if that would be appropriate. Thanks.

[Z71-K9]

Wow you guys are getting crazy mileage. My '12 only gets 11 around town.

[RyanbabZ71]

Wow you guys are getting crazy mileage. My '12 only gets 11 around town.

 

I get about 12 running e85

 

 

Ryan

 

 

[pendragon]

Denali's got the L94 6.2 which DOES have AFM.

What about the 2013? has it got AFM?

[pendragon]

Has anyone put a programmer on the 6.2? If so which one and how do you like it? Extra HP extra mileage?

 

Have a new 2013 Denali arriving in days, grabbed a Diablo Intune so that I could program tire sizes and remove the speed governor, turns out it has a slew of other options, Diablo figure their 93 tune will add 30 HP

[Chris]

Denali's got the L94 6.2 which DOES have AFM.

What about the 2013? has it got AFM?

 

The SUV with the L92 6.2 has AFM. The Truck with the L9H does not

 

Sent from my Samsung Galaxy S4 using Tapatalk 4

 

 

[pendragon]

My 2010 Denali has got 16 mpg consistently for the last 50,000 miles, most of my driving is higway on cruise.

[Daryl Z71]

Mine has leveled out at 14.3 mpg.

[madocwilliams]

I need some help, so many tuners to choose from and I want the one that gives me the most bang for my buck. I have a 2011 GMC Denali with the 6.2 any suggestions on which ones are the best ones for the motor. I want longevity out of my truck but I also want to add some horse power and fuel economy.