2015 Denali/Yukon 6.2 thoughts

[Hallowed_point]

Thinking about trading in the 6-6 on a 2015+ Denali or Yukon 6.2(2014's apparently had engine issues.) Would use it to tow the Camaro to track days and daily drive in the winter/fall. Besides the horrendous fuel economy is there anything I should know about?

https://www.youtube.com/watch?v=NAg3yRExGd4

[Twin_Cam_Turbo]

The 8 speed trans seem to have some annoying drive ability issues, one of ours has shift flares on upshift and occasionally a 3 second delay when putting it into gear. The fuel economy isn’t as bad as I’d have thought, towing my company car with half tons usually is around 13-14L/100km at 120km/h.

[Hallowed_point]

The 8 speed trans seem to have some annoying drive ability issues, one of ours has shift flares on upshift and occasionally a 3 second delay when putting it into gear. The fuel economy isn’t as bad as I’d have thought, towing my company car with half tons usually is around 13-14L/100km at 120km/h.


That's actually not bad at all given the power. I typically drive 80% highway anyways for work.

[ExtraSlow]

Do those years have the cylinder deactivation? If so, when not towing it should get pretty good highway economy.

I like that engine. And those trucks too.

[Twin_Cam_Turbo]

Do those years have the cylinder deactivation? If so, when not towing it should get pretty good highway economy.

I like that engine. And those trucks too.

Yes they do. They are reasonably efficient for what they are.

[SkiBum5.0]

Some reported issues with a harmonic vibration - widely spread across GM trucks and big SUV's. I think mechanically they are pretty stout. Rare case of collapsed lifter because of cylinder deactivation.

[Masked Bandit]

Do those years have the cylinder deactivation? If so, when not towing it should get pretty good highway economy.

I like that engine. And those trucks too.

GM has had cylinder deactivation in their full size units since at least 2007. Strangely thought my 2005 Avalanche got better fuel economy than my buddy's 2008. Could just be driving style though.

[Hallowed_point]

I would certainly be deactivating any cylinder deactivation.

[corsvette]

Ours was very reliable, it's a 15 so it only has the 6 speed/6.2 which is still plenty quick. I got a bullydog tuner and that improved the shifting 100% as the factory tune always wants to see the next high gear, plus it eliminated the occasional hard shift while slowing down. I also got rid of the 22" wheels, the new body trucks seemed to really ride rough with them, 20's settled things right down. F/E was as stated not bad for a big rig with 420hp, but they recommend premium and thats what I ran especially with the tune. These are great trucks imo.

[Hallowed_point]

Thanks all. Always prefer real world reviews

[Darkane]

Big fan of the 6.2, driven one but own a 2015 5.3.

Fuel economy is great, and Ive heard the 6.2 actually has enough grunt at our altitude to maintain V4 mode more often and is fairly close to the economy of the 5.3. I’d go for it.

[nissanK]

I would certainly be deactivating any cylinder deactivation.

I'm running a 2014 SLT with the 6.2 and 6 speed. Running a Diablew tune since 50,000kms to de-activate the V4 mode and smooth out the shifts and she runs like a dream. Alot of the oil consumption problems are due to the cyclinder de-activation and with the Diablew tune I'm running the same (if not a little better) fuel economy without dropping to V4 mode.

Had some lifter tick show up around 108,xxx kms and luckily it was covered under powertrain warranty still. Never towed before the lifter tick so I suspect mine was a one-off and I haven't seen any mention of it being a widespread issue on any forums.

I also don't have the dreaded harmonic vibration some people have been experiencing.