2019 Canadian Truck King Challenge

[ib516]

The powertrain in the GM twins (6.2L V8/10 speed) is certainly impressive! Good mpg and class leading power. Too bad they didn't have an E-Torque Ram to test, I wonder what difference it would have made mpg wise. Anyway, here's the VIDEO.

[Groover]

ShinerBock wrote:

Lessmore wrote:

ShinerBock wrote:

ksss wrote:
I have never owned a 6.2L in a pickup, I have several friends that have them. They run midgrade, which here is 87 they have never had issue. I have an LSA in my Camaro. I run 91 in that only, we don't have 93 octane here. I don't know what the fall off in mpg is, but unless the pickup can sense the octane level and detunes itself, there is no more energy in a gallon of 91-93 than there is in a gallon of lessor octane. The knocking, that is addressed by the higher octane. I don't know anyone here that has that issue but not to say someone hasn't.

Are they the new L86 6.2L engines? The L86 is direct injected and have a much higher compression ratio of 11.5:1 than the older LSA 6.2L that was 9.1:1.

My 2015 Impala has the DOHC V6, 4 valves per cylinder, 305 hp engine with a compression ratio somewhere in the 11 to 1 area. The manual says regular gas is fine and out here that is 87 Octane. I think I have used 85 octane regular gas...in some areas of the states...with no issues.

I stated compression ratio and direct injection because that is the major difference between the old 6.2L and new one. However, it is not just about compression ratio that determines the octane requirement.

Combustion chamber size(the bigger the chamber the more timing is needed), RPM, emission controls, and other variables also plays a big role in engine timing/tuning. Your small chamber 3.6L may be tuned to achieve that 305 hp with regular fuel and can adjust timing(to an extent) for more power with premium fuel. The large chambered 6.2L on the other hand may be tuned for higher octane to achieve its 420 hp power levels, but reduces power on lower octanes

Wide band knock sensor will allow for some timing adjustment, but conditions can exceed the amount that can be adjusted.

Yeah, knocking is frequently caused by spontaneous combustion from heat of combustion just like in a diesel. If that is going on you can take the spark plugs out and throw them away and you will still have knock. Backing off the throttle and keeping the revs up will help some but the control systems will fight you on that in an attempt to keep up fuel economy.

I am trying to avoid taking a side on whether 93 octane is required but the wording in the manual is very suggestive that it is. I wonder what happens to your warrantee if you use 87 octane? That may be the most important consideration. Either way, the wording is strong enough that I consider that engine not suitable for my use and will stick with my EcoBoost that delivers similar results with regular fuel.

[ShinerBock]

Lessmore wrote:

ShinerBock wrote:

ksss wrote:
I have never owned a 6.2L in a pickup, I have several friends that have them. They run midgrade, which here is 87 they have never had issue. I have an LSA in my Camaro. I run 91 in that only, we don't have 93 octane here. I don't know what the fall off in mpg is, but unless the pickup can sense the octane level and detunes itself, there is no more energy in a gallon of 91-93 than there is in a gallon of lessor octane. The knocking, that is addressed by the higher octane. I don't know anyone here that has that issue but not to say someone hasn't.

Are they the new L86 6.2L engines? The L86 is direct injected and have a much higher compression ratio of 11.5:1 than the older LSA 6.2L that was 9.1:1.

My 2015 Impala has the DOHC V6, 4 valves per cylinder, 305 hp engine with a compression ratio somewhere in the 11 to 1 area. The manual says regular gas is fine and out here that is 87 Octane. I think I have used 85 octane regular gas...in some areas of the states...with no issues.

I stated compression ratio and direct injection because that is the major difference between the old 6.2L and new one. However, it is not just about compression ratio that determines the octane requirement.

Combustion chamber size(the bigger the chamber the more timing is needed), RPM, emission controls, and other variables also plays a big role in engine timing/tuning. Your small chamber 3.6L may be tuned to achieve that 305 hp with regular fuel and can adjust timing(to an extent) for more power with premium fuel. The large chambered 6.2L on the other hand may be tuned for higher octane to achieve its 420 hp power levels, but reduces power on lower octanes

Wide band knock sensor will allow for some timing adjustment, but conditions can exceed the amount that can be adjusted.

[Lessmore]

ShinerBock wrote:

ksss wrote:
I have never owned a 6.2L in a pickup, I have several friends that have them. They run midgrade, which here is 87 they have never had issue. I have an LSA in my Camaro. I run 91 in that only, we don't have 93 octane here. I don't know what the fall off in mpg is, but unless the pickup can sense the octane level and detunes itself, there is no more energy in a gallon of 91-93 than there is in a gallon of lessor octane. The knocking, that is addressed by the higher octane. I don't know anyone here that has that issue but not to say someone hasn't.

Are they the new L86 6.2L engines? The L86 is direct injected and have a much higher compression ratio of 11.5:1 than the older LSA 6.2L that was 9.1:1.

My 2015 Impala has the DOHC V6, 4 valves per cylinder, 305 hp engine with a compression ratio somewhere in the 11 to 1 area. The manual says regular gas is fine and out here that is 87 Octane. I think I have used 85 octane regular gas...in some areas of the states...with no issues.

[Bionic_Man]

My '11 Yukon Denali doesn't like anything other than premium.

[ksss]

GWolfe wrote:
My only problem with GM and the 6.2 is that you have to buy a higher trim level to get it, not everybody wants to buy a Denali or LTZ to get it.

That makes a lot of people upset, but it makes GM a lot of extra money. They sell all of the 6.2's they can build, I think they just figure might was well limit it to the upper trim lines and maximize profits.

[GWolfe]

My only problem with GM and the 6.2 is that you have to buy a higher trim level to get it, not everybody wants to buy a Denali or LTZ to get it.

[ShinerBock]

mooky stinks wrote:
I had a 2015 6.2 that I put 40k miles on. I mostly mixed equal amounts of 87 and 93. If I didn't run 90-91 in it, I could make it ping on demand. The once or twice that I put 87 in it, it was barely drivable. Forget towing with anything less than 91. I ran 93 whenever towing. I'm not aware of any changes they've made to change that.

Thank you for your subjective post.

[mooky_stinks]

I had a 2015 6.2 that I put 40k miles on. I mostly mixed equal amounts of 87 and 93. If I didn't run 90-91 in it, I could make it ping on demand. The once or twice that I put 87 in it, it was barely drivable. Forget towing with anything less than 91. I ran 93 whenever towing. I'm not aware of any changes they've made to change that.

[MARK_VANDERBENT]

GMC is a fine new truck. Seems it has been winning alot of shoot outs lately. I do love the front end look of the silverado. To me it stands out so differently than the others. Just looks tough I think.

[ShinerBock]

I am just going by what a few old customers and others have stated here. All said they noticed knocking using less than premium fuel. Doing a Google search, it seams there are others in the Chevy truck forums as well and seems to be a heated topic there. Either way, it states the the manual that premium is needed to achieve max power and efficiency regardless of what is "felt" by users here and I dont trust butt dynos because we all know how accurate they are.

[Ductape]

Modern engines use knock sensors to dynamically adjust the timing to suit the fuel. You'll never hear it knocking unless there's a real problem.

[ktosv]

I can tell you that a 2019 Camaro SS runs just fine with regular gas. In fact, with about 700# (people and luggage) the car would do 0-60 in the low 4’s...published times I found are 4 flat. Doesn’t seem to be much loss of performace considering the weight in the car. Either that or I am a pretty good driver and had an awesome launch!!

Maybe the knocking would be appearant under heavy loads such as towing?

[Bigfoot_affair]

LSA = 6.2 supercharged. Found in the ZL1 and CTS-V

My Dad has a 2018 Denali with the 6.2 and has had zero issues running 87.

[ShinerBock]

ksss wrote:
I have never owned a 6.2L in a pickup, I have several friends that have them. They run midgrade, which here is 87 they have never had issue. I have an LSA in my Camaro. I run 91 in that only, we don't have 93 octane here. I don't know what the fall off in mpg is, but unless the pickup can sense the octane level and detunes itself, there is no more energy in a gallon of 91-93 than there is in a gallon of lessor octane. The knocking, that is addressed by the higher octane. I don't know anyone here that has that issue but not to say someone hasn't.

Are they the new L86 6.2L engines? The L86 is direct injected and have a much higher compression ratio of 11.5:1 than the older LSA 6.2L that was 9.1:1.