2 Mods killed my mpg?

[Justin Nachazel]

Hello everyone,

 

So I just installed a muffler and repositioned my flapper to be in front of the muffler. Since then as a result I don't get any drone one thing I've noticed is that the mpg went down by 5. I haven't been revving it, in fact I've been more light on the throttle than usual just to see if I could get those numbers back up. The only other mod that I did at the same time was switching out my DeeZee sidesteps with the AMP Research Powersteps.

 

Here are my best guesses maybe someone with technical knowledge can help?

 

1) Flapper relocation is causing MORE back pressure by having it prior to the muffler which is causing dampening in the engine making it work harder

2) The DeeZee side steps might have actually been helping with airflow around the truck since I'm keeping the air dam, by switching to low profile AMP Powersteps It creates more air turbulence around the truck.

 

I didn't expect to gain mpg or anything but I also didn't expect to lose mpg. It should have at least stayed the same.

 

[GTD]

Why did you have flapper installed ahead of muffler? Have to believe GM engineers positioned the valve after the muffler for a reason. I'd have to say you've created a restriction that has hurt efficiency.

[Justin Nachazel]

Why did you have flapper installed ahead of muffler? Have to believe GM engineers positioned the valve after the muffler for a reason. I'd have to say you've created a restriction that has hurt efficiency.

 

The only reason I repositioned it there was another member had relocated it which got rid of the drone.

[Vic15]

I don't think the step is contributing to a loss in mpg. If anything, I think it might help, less drag.

[NitroDatsik]

Have you hand calculated your mpg or are you judging by the tiny screen?

 

2014 Silverado 2WT CC Summit White 4.3L V6

DROPKICK Edition

IG: jorge_dropkick_rangel

https://m.youtube.com/user/jorgerangel159

[Justin Nachazel]

Have you hand calculated your mpg or are you judging by the tiny screen?

 

2014 Silverado 2WT CC Summit White 4.3L V6

DROPKICK Edition

IG: jorge_dropkick_rangel

https://m.youtube.com/user/jorgerangel159

 

Im judging the loss off the tiny screen. I was getting 20 before and now I'm avg 15 on the same drive

[NitroDatsik]

 

Im judging the loss off the tiny screen. I was getting 20 before and now I'm avg 15 on the same drive

The screen is always off on my truck. I always hand calculate it for that reason, but I don't think what you did could have a great impact, my guess is wind resistance and bad reading of the computer screen

 

2014 Silverado 2WT CC Summit White 4.3L V6

DROPKICK Edition

IG: jorge_dropkick_rangel

https://m.youtube.com/user/jorgerangel159

[Justin Nachazel]

The screen is always off on my truck. I always hand calculate it for that reason, but I don't think what you did could have a great impact, my guess is wind resistance and bad reading of the computer screen

 

2014 Silverado 2WT CC Summit White 4.3L V6

DROPKICK Edition

IG: jorge_dropkick_rangel

https://m.youtube.com/user/jorgerangel159

 

What do you mean by wind resistance? I haven't changed anything that should effect that though except the sidesteps which should have helped right ?

[NitroDatsik]

That when you were getting 20mpg there wasn't any wind resistance and when you were getting 15 there was and your truck had to work harder to get your desire speed. Or your new exhaust system made your feet happy and you put the peddle to the metal but don't realize it cus it sounds to good lol. Have you reseted your average mpg screen?

 

2014 Silverado 2WT CC Summit White 4.3L V6

DROPKICK Edition

IG: jorge_dropkick_rangel

https://m.youtube.com/user/jorgerangel159

[Justin Nachazel]

That when you were getting 20mpg there wasn't any wind resistance and when you were getting 15 there was and your truck had to work harder to get your desire speed. Or your new exhaust system made your feet happy and you put the peddle to the metal but don't realize it cus it sounds to good lol. Have you reseted your average mpg screen?

 

2014 Silverado 2WT CC Summit White 4.3L V6

DROPKICK Edition

IG: jorge_dropkick_rangel

https://m.youtube.com/user/jorgerangel159

 

I did the reset on the avg mpg screen and its low still. I still don't know what you mean by wind resistance. Are you saying that the weather was effecting it? I haven't been laying on the gas though for sure.

[arkenzo]

Did the other member have MPG issues after the flapper relocation? Flapper valve opens by pressure in the exhaust correct? Relocating it so far down the exhaust might have cause some blockage and it not open anymore? Just a thought.

[NitroDatsik]

 

I did the reset on the avg mpg screen and its low still. I still don't know what you mean by wind resistance. Are you saying that the weather was effecting it? I haven't been laying on the gas though for sure.

Yes weather affecting it. You can feel when the wind is pushing on the truck, makes it feel heavier, that's a big factor on your mpg.

 

2014 Silverado 2WT CC Summit White 4.3L V6

DROPKICK Edition

IG: jorge_dropkick_rangel

https://m.youtube.com/user/jorgerangel159

[Spurshot]

I'd figure out how to check that valve while driving, to ensure its opening. If it is restricted from opening all the way, it would have an adverse effect.

 

No way in hell the steps would have that much effect one way or another. Steps of any type would probably not have a measurable effect in the mpg.

 

If the wind hasn't been unusual, I would discount that as well. As long as it's been the same as the earlier comparison and you're driving the same route.

[bdbake01]

No way this caused it. Even a stuck flapper wouldn't do it.

[NitroDatsik]

Best and final way to really check, is fill up to full, when pump clicks. Reset trip miles. Drive your daily routine, fill up again next morning, now divide your trip miles by gallons you pumped and that will be your average mpg and compare it to the screen average mpg.

 

2014 Silverado 2WT CC Summit White 4.3L V6

DROPKICK Edition

IG: jorge_dropkick_rangel

https://m.youtube.com/user/jorgerangel159