Quote:
Originally Posted by Norm Peterson
My understanding of forced induction is that it needs to be calibrated a little richer than NA when under boost, so at the same power output as a larger NA engine it will use more fuel when they're both making that level of power.
It's because under conditions where you aren't into boost that the smaller FI engine drops back into essentially NA mode that you make any fuel economy gains. So it makes sense to let the turbo engine stay out of boost during the emissions and mpg certification as much as possible.
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That's kinda the tree I was barking up. These small turbo engines behave very nicely for the gentle, unrealistic EPA cycle, but once even a little out of the parameters of that, they change into a different animal. So the EPA gets their numbers, and the consumer gets very little actual benefit for a great deal additional expense.
And some of these engines are getting small to the point that you don't necessarily have to be demanding that much power to make spooling up the turbos necessary. All it may take is a small hill with the cruise set.
Quote:
Originally Posted by GretchenGotGrowl
Yeah, I got better MPG than the sticker said on my Cruze and I'm getting better MPG on my EcoBoost F-150 than the sticker claimed. You just have to learn to keep out of boost when you don't need it.
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The same can be said of any engine. The N/A cars I've driven have always beat their EPA targets, often by significant margins. It's in how you drive, not what you drive. And most people don't drive well in terms of efficiency. FI engines are no magic bullet.
Quote:
Originally Posted by Norm Peterson
I think it's got something to do with catalytic converter durability.
Ford does the same thing, and aftermarket tunes are somewhat leaner.
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There are good reasons for it. Snoop around the internet and find out what happens to a 5.0 when the tuner goes a little too lean.
Quote:
Originally Posted by 90503
Am enjoying all you boys' expertise..."Real world" mileage I'd say is a non-issue...I don't think anybody really expects to get what is advertised...The "rated" mileage on the window sticker is what will rule the day, and determine what is offered for sale...
...Also, I'm just not seeing where a V-6 would fit into all this...I think Norm said earlier that the total year numbers for the Camaro would make GM hard-pressed to sell three different engines...as well as a ttv6 being more expensive and not as efficient as the v-8.???.....Things are getting as clear as mud!...lol...
Please carry on, and thanks....
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I share your frustration. Reality has taken a back seat to regulation which in itself is becoming more disconnected with reality every day. Remember the day when the automakers could build cars, and not just a regulator's or legislator's (whom may or may not have relevant knowledge of the field) blueprint of what they think transportation should be?