ChevyTech77

Wouldn't waste my money on an intake or exhaust mods for this engine as the two factory installed systems are about as good as it gets already. You guys getting 12.5 mpg at 80 mph must be somewhere really cold, your truck is an NHT build or you have some mods done to it that have affected your mileage (tires/wheels/etc) because mine will still pull down 16 mpg flat at 80 in 35 degree weather but I'm just a Z71 and all stock so.......

The 6.2 L9H is offered in the NHT Max-Trailering package that is capable of towing 10,500 lbs, yes. My truck is just a Z71 so I only have 3.42's.

Yup, If I lock out 5/6 gears in town it actually goes down to 11-13 mpg in town but I'm usually beating on it pretty good at the same time, as well. I live in a large city and only drive 4 miles round trip to work everyday too so I'm usually no better than 15 mpg on average.

First off, they don't make a 3/4 ton with the 6.2 L9H engine. Second, I average 15-18 mpg depending on how I drive it. Lowest I've seen is 12, highest was 19.5.

My avatar is all the other trucks need to know and get to see.

The best part is that I had the forcast '12 powertrain build/install sheet right in front of me when I was making that post. Oh well. LOL.

My bad, my eyes jumped down a few lines in the engine application roster. L94's were for 6.2 utility applications only so a Sierra Denali 1500 series, should have the L9H not the L94.

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

Best time I've netted so far with mine is a 14.6 at 96.3 mph. That's traction control off and the rear tires (factory Z71 18's) rolling in smoke for the first 20-30 feet. If I left the traction control on then yes, 15.8's easy. I'd love to get mine on a set of half bald Eagle LS's with some traction compound down in auto 4WD and see what it does. I'd be willing to bet if I could get it to hook instead of spin for half of the first 60' (60' times were HORRIBLE as you would guess, btw) it should pull down a good very high 13 or 14 flat time. My buddies '11 Hemi/EX Cab/SB with factory 20's couldn't break into the 15's. 16.3 was his best.

Apologies, that is how it read to me. No need. I'm no english major but after re-reading it a few times, before I posted it, it seemed fine to me. In hindsight, I can see how you came to the conclusion that you did, as well.

I never implied that the L9H had AFM, only that the LS3 does not. I am fully aware that the L99 does have AFM, however.

Diffferent cam and heads between the LS3 and L9H.The LS3 also has no VVT, AFM and it is not E85 compatible. The L99 is a closer sibling to the L9H than the LS3 is.

The L9H club. I like it!

will it cause the truck to go into any sort of limp-mode? Not that I am aware of other than having to stare at those lights/messages on all the time in the dash.

Pulling the fuse will disable abs, traction and stability control.

The stability and traction system will default to off with any engine/trans driveablility issue. Get the check engine light/driveablility concern fixed first and the rest will be history.

So the truck has rear leveling suspension and/or electronic suspension control?? Either way, that wouldn't net you a service STABILITY or TRACTION light unless you damaged the wiring going to the rear wheel speed sensor that is in the axle tube near the brake rotor. If it DOES have leveling or electronic suspension, you'd have a service SUSPENSION system message and yes, that could be easily caused by replacing the shock. Need more info.