So like many of you, I was bummed that GM picked the Camaro/crossover suited LFX high feature 3.6 L engine for the new canyorado, instead of the orphaned but excellently suited to truck use 4.3 L ecotec III. After all, why go to the trouble of created a unique V6 meant for truck use to only use it on one truck, and a truck where it will be lowly base engine at that?

(photo credit GM inside news)

(photo credit GM authority)

I hear you say that the 3.6 is smaller, therefor lighter and easier to fit? No, the LFX weighs ~370 lbs, the 4.3 weights ~ 375 lbs from the best sources I can find. Dimensionally the LFX is bigger too, due to its DOHC vs pushrod arrangement.

Well the 3.6 has more HP! I mean look at that graph, its crazy!

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Well, yes, its a very impressive looking graph with big (though jagged) peaks. Compare that to 4.3 and it looks even better.

Riiiight up until the point you notice the scale on the graphs for HP and Torque. If it looks wonky its because it is. I couldn't find detailed numbers so I did my best at trying to read the graphs to come up with my own that more accurately reflects a uniform scale

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(Sorry for the graph, I don't normally into excel)

RED is the 3.6 torque curve, Purple is the 4.3 torque curve

Blue is the 3.6 HP curve, Green is the 4.3 HP curve.

As you can see the 4.3 has more torque everywhere, though the curve is a little more peaky. The 4.3 also has more power in more places, its only in the last reaches of the rev band (where the 4.3 redlines out) that the 3.6 has an advantage.

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Other 4.3 advantages (that I know about)

  • Higher alternator (for less water damage risk)
  • As good as timing chains are you don't need to worry with cam in block
  • the 4.3 will run 297 hp and 330 ft-lbs on e85, the 3.6 doesn't change
  • the 4.3 has lower compression for longer life
  • The 4.3 is based on small block architecture for modularity for the OEM parts and aftermarket.

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So, smaller, same weight, more power in more places and available. Why isn't this the engine in the Canyon/Colorado and what else are you going to use it for GM?