Just bought the wife a 2014 Traverse. I know take it easy on me. It is direct injection but not flex fuel.
I may be wrong but with the cooling effect of the ethanol, it could pose a problem of keeping enough heat in the cylinder for complete combustion. When ethanol changes from *liquid to gas on the way to combustion, it absorbs 2.6 times more heat than gasoline. I know this is beneficial for power production but its also a problem in MPG because ethanol’s energy density is roughly 66 percent that of gasoline. Who remembers the 1962 Oldsmobile F-85 Jetfire’s V-8? It was GMs first production turbocharged vehicle that ran a dual fuel. Ran a separate tank with a mixture of methanol and water and a regular fuel tank for gasoline. (sound familiar?) I think we are seeing a few tweener years hear until they get the whole CAFE requirements figured out for affordable and reliable production.
My 2011 6.2 is tuned for e85 so I can definitely see the result of the fuel. We will be changing the race car to e85 as well. Tired of the $12 per gallon for racing fuel.

 

If you are making the argument that DI is reasoning for no E-85 on the 6.2, that doesn't make sense. E-85 is available on the 5.3, so the combustion process of direct injection is an invalid point.

 

That's why I'm asking the question - I don't know how much more fuel the 6.2 would need than the 5.3.

 

Flex fuel delivery system can handle more fuel volume as the result of the demands for E85 and therefore is easier to accomodate boost.

The 5.3s like boost better anyways.

 

This is why I prefaced with "I may be wrong". No valid or "invalid " point to be made here. No argument over the flow capabilities of the DI system either.
Only throwing ideas (right or wrong) on the wall when someone else asked " anyone else have any ideas"?
So are you saying they just throw a 5.3 tune on the 6.2 and let it roll?
Just asking?

 

Not what I'm saying at all. I have no idea why the 6.2 is not E85 rated and the 5.3 is. But I highly doubt the direct injection fuel system is the reasoning behind it.
To my understanding, there is a lift (priming) pump to a high pressure pump in the valley. The cam(?) driven valley pump ups the pressure to direct injection levels. I highly doubt a cubic inch bump from 5.3-6.2 will adversely effect that high pressure. On pre DI engines, the fuel pump was a limiting factor due to needed fuel volume. I think the DI negates that.

Please, some one correct me if im wrong.

For reference, I'm using my (limited) diesel knowledge as a basis. I know it's different fuels- but similar principles.

 

Interesting ideas, SLC.

I'm still hoping that one of these days somebody will actually know the reason.

 

You are correct about the DI comparison to diesel but only just by a direct injection into the cylinder. Ignition is still separate on gas. Since gasoline has a much higher flash point a spark is still needed to ignite and assist with the burn. My only assumption is by not having the 6.2 flex fuel would be the CAFE standards GM has to meet in the future. They have quite a few vehicles in the past that were flex fuel but in 2014 the same product line was either limited flex fuel production or completely eliminated from the dual fuel.
I know all the manufacturers are testing newer type engines to be smaller and still maintain the power levels to get to those CAFE numbers. Turbocharging seems to be the most prevalent method at this point. From some info I've seen they are using almost diesel like compression ratios to get the power levels up.
But I guess only the General knows! Hell maybe they ran out of parts? Or maybe its Obama Care?

 

Ha ha. . . . Obama care . . . . .

 

Any new news on weither this is gonna be a go or not?