GM 6.2 Liter

[We_ll_See]

I'm considering ordering a new GMC Sierra 1500 with the max tow package. It would be a crew cab short box SLT trim. I can either get the 5.3 or the 6.2 liter. Both have the 8 speed transmission.

I have looked at GMC's brochure, looked on their website, and done some searching of forums and it does NOT appear that the 6.2 requires premium fuel for the 2016 or 2017 model year. Has anyone heard or read differently?

The 6.2 obviously has a lot more power and torque but it is a $2,500 option and I have no desire to pay for premium fuel.

[lbrjet]

minnow wrote:
Why isn't the 6.2 available in the HD level trucks?

Not made with a cast iron block.

[minnow]

Why isn't the 6.2 available in the HD level trucks?

[hawkeye-08]

when we had our 2008 Yukon XL Denali with the 6.2, mpg was better with premium, enough that it was less cost to use premium. I never heard a knock on either. The acceleration was just plain awesome.... as my wife said, it had whoomba where the 5.3 does not...

[We_ll_See]

jcgib81 wrote:
I have a 2011 Yukon xl Denali with 6.2 and run reg 87 when driving normal, and Premium when I tow. Engine is a beast.
I had a 5.3 Suburban and it was a slug compared to this SUV and milage is about 2-3 mpg less.
Just my opinion.

That is what I'm leaning towards doing.

Everyone who has driven the 6.2 says it's a great engine and a huge upgrade over the 5.3.

[jcgib81]

I have a 2011 Yukon xl Denali with 6.2 and run reg 87 when driving normal, and Premium when I tow. Engine is a beast.
I had a 5.3 Suburban and it was a slug compared to this SUV and milage is about 2-3 mpg less.
Just my opinion.

[Dadoffourgirls]

My post was straight from the owners Manual. APT provided a link.

[APT]

GM Owners Manuals

[We_ll_See]

Dadoffourgirls wrote:
From the 2017 Manual:
For the 6.2L engine, premium
unleaded gasoline meeting ASTM
specification D4814 with a posted
octane rating of 93 is highly
recommended for best performance
and fuel economy. Unleaded
gasoline with an octane rated as low
as 87 can be used. Using unleaded
gasoline rated below 93 octane,
however, will lead to reduced
acceleration and fuel economy.
If knocking occurs, use a gasoline
rated at 93 octane as soon as
possible, otherwise, the engine
could be damaged. If heavy
knocking is heard when using
gasoline with a 93 octane rating, the
engine needs service.

Is this straight from the GM owners manual? Where did you find this if you don't have a 2017 with the 6.2. I appreciate you posting it.

[Bionic_Man]

Every review I have read/seen shows the 6.2 getting at least equal, and usually better MPG than the 5.3. And there is no comparison when it comes to power.

I believe the 6.2 is the best engine put into a 1500 series vehicle today. And I am a MOPAR guy.

[manley]

There's a whole lot of "don't know what they're talking about" going on in this thread.

[mooky_stinks]

Dannyabear1 wrote:
The 6.2 is an all aluminum 'hot rod' engine, not designed or reccomended for towing, that's why it is not available in 2500 or 3500 trucks. They still rely on the Old dependable 6.0.

[Dannyabear1]

The 6.2 is an all aluminum 'hot rod' engine, not designed or reccomended for towing, that's why it is not available in 2500 or 3500 trucks. They still rely on the old dependable 6.0.

[mooky_stinks]

My 15 in my signature has been driven with different octanes. 87, forget it, even when trying to baby it, it rattles like a can of spray paint. 89 I can get away with if I'm easy on it. I can also make it ping on demand. 91 it will not ping unless I'm towing. Then it pings slightly at times. 93 will not ping at all no matter what UNLESS I have run into a dishonest gas station selling less than advertised octane. It has happened. Mileage is better than my 5.3/6 speed by 1-2 mpg.

[manley]

I have a 2010 with the 6.2. I've run premium, and I've run regular. The mileage is going to stink, no matter what you run, but the power is impressive.

Mileage towing is from 7-9, depending on the terrain, winds, and speed.
Mileage around town is about 11-12.
Mileage on the highway is 17-19, depending on speed.

It has NEVER spark knocked, not even once. I've actually run premium for extended periods of time and before, during, and after towing, trying to calculate the costs relative to the MPG. I can't make it pay, and the performance difference is negligible so I usually just run regular unleaded.

That's just my experience, and your experience may vary.
From 2010 to 2016/17 is a huge difference, so it very likely will vary.