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5.3L 3.42 vs 3.73 fuel economy?

ryeguy

By ryeguy
in Engines & Drivetrain

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iCryWheniGoPoop Enthusiast

iCryWheniGoPoop

Posted
Posted

Yes I do see why you have been married so long, after reading this post I think I may be in love with her as well. Sorry?

KARNUT Senior Enthusiast

KARNUT

Posted
Posted

That smile in High School did it for me. It took a year to get her to go out with me. I had a bad rep. for my aggressive driving. There was this long strait road just after the high school 13 school busses was my record. It wasent long the buses would wait for me to leave first. The kids in school would come get me to drive there cars when there was a race, I could flat shift the tac would never move. At Atco drag strip of course.

iCryWheniGoPoop Enthusiast

iCryWheniGoPoop

Posted
Posted

13 school busses isn't very far in my world (check out my avatar) but cool story non the less. We need to sit down and have a beer sometime.

KARNUT Senior Enthusiast

KARNUT

Posted
Posted

When I get a few more miles on the truck, Ill have to drive to your neck of the woods, get a tune or talk you out of one of those turbos gathering dust in your shop. For a fee of course.

iCryWheniGoPoop Enthusiast

iCryWheniGoPoop

Posted
Posted

When I get a few more miles on the truck, Ill have to drive to your neck of the woods, get a tune or talk you out of one of those turbos gathering dust in your shop. For a fee of course.

Sounds like a plan... Maybe they will be mounted to something by the time you come up and we can just go for a ride.

calgator73 Senior Enthusiast

calgator73

Posted
Posted

Completed my trip. On my trip to Knoxville I stopped at a 1/2 tank and again upon arrival. First leg I-64W to I-81S was 18.5. Second leg I-81S to I-40W 21.5. Cruise control set to 74 with no A/C. Return trip 19.5 and 20.5. Trip to Hilton Head straight down I-95 no traffic, no A/C cruise set to 74 was 20.5. On the way home I set the cruise control to 78 with A/C on and recorded 19.5 until I jumped off at emporia. I wish it were a little better but I have the 3.73 so I guess it's okay.

fondupot Senior Enthusiast

fondupot

Posted
Posted

Those arent bad numbers at all considering you were going 74 and 78 mph....if you were within the range that the EPA tests the cars at (55-65 mph) you would have easily gotten the sticker rated MPG of the truck....

Northside Enthusiast

Northside

Posted
Posted

Oh yeah, you will hate switching back then, even though it is your put put in the family. Even though the power is subtle when switching to E85, it seems massive coming back down. It's like crack.... Awesome till you run out. Unfortunately I have an E85 drug dealer hanging out on the corner every day on the way to work so the convenience makes it even harder.

Do you suppose that the subtle change going to E-85 is because the "brain" takes time to adjust to the high octane fuel? When going back to E-10 I would guess that it would adjust back quickly because it can sense detonation on the lower octane fuel. My truck feels way more powerful now that I've run E-85 for a while. I suppose it's breaking in too, and that would have a little to do with it. I am not looking forward to using E-10 into it when I travel. I guess I'm hooked.

fondupot Senior Enthusiast

fondupot

Posted
Posted

I did about a 270 mile round trip yesterday. got between 20-22 mpg the whole time. This was back country highway with strips of little towns. But I was going about 65 mph most of the time.

 

5.3L and 3.42 gears

iCryWheniGoPoop Enthusiast

iCryWheniGoPoop

Posted
Posted

Do you suppose that the subtle change going to E-85 is because the "brain" takes time to adjust to the high octane fuel? When going back to E-10 I would guess that it would adjust back quickly because it can sense detonation on the lower octane fuel. My truck feels way more powerful now that I've run E-85 for a while. I suppose it's breaking in too, and that would have a little to do with it. I am not looking forward to using E-10 into it when I travel. I guess I'm hooked.

It's not adjusting to octane level... The ECM is adjusting to alcohol content in the fuel. This process is the enrichment of fuel by changing your stoichametric value depending on the alcohol content. This stoich value is what all fueling is based off of or better put as the constant in all calculations for fueling. Really the only other thing changing is a slight amount of timing. It changes the same speed either way but the engine likes the alcohol, so it seems to perk up quickly and will actually be lean for a little while until it adjusts. When you go back to gasoline your engine is actually running really rich and will be low on power, lower than if you had been running gasoline for a few tanks, I would guess somewhere around 15-20 hp actually. It will increase in power from the time you put gas back in it for a hundred miles or so, until the engine leans back out where it needs to be for gas.

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