put a flowmaster 40 series on

[pizzle]

So i had a muffler put on my 06 tahoe. Sounds great but ive noticed a drop in MPG. I know people say its because you step on the pedal more now but i tested in a few long trips and its a 1.0 MPG less then it was.

Anyone else experience this? I was looking at my tailpipe yesterday and it looks to be a an upward angle. Would this have any affect on MPG?

Thanks

 

[mizzouguy]

Is the new muffler a smaller diameter than stock? Oem is 2.75". Upward angle won't hurt besides looking (in my opinion) dorky and collecting water.

 

[pizzle]

Is the new muffler a smaller diameter than stock? Oem is 2.75". Upward angle won't hurt besides looking (in my opinion) dorky and collecting water.

No its the same diameter as the original............i mean i keep the original pipe so it has to be. I looked at the muffler and there is no reducer or anything like that.

Did you just call me a dork?! It has a slight upward angle not major. I just want to know if that has an affect or if I should have it corrected

 

[mizzouguy]

No its the same diameter as the original............i mean i keep the original pipe so it has to be. I looked at the muffler and there is no reducer or anything like that.

Did you just call me a dork?! It has a slight upward angle not major. I just want to know if that has an affect or if I should have it corrected

Flowmaster 40 series are not available in 2.75.
http://www.flowmastermufflers.com/?page_id=11118
A 40 is a lot shorter than oem, so they would have had to add an extra length of pipe. Usually you can see a difference in pipe size somewhere.

No, lol, I wasnt calling you a dork. Tailpipes sloping up are just a pet peeve of mine. It doesnt allow for proper drainage of condensation. Not a huge deal but can lead to rusting out. If you look close at your original muffler it has a drainage hole because it is the lowest point of the system before it humps over the axle. I doubt it would have a negative affect on mpg on a stock engine. At all.

 

[pizzle]

i hear u i dont like it either. Something is affecting the MPG

 

[pizzle]

has anyone ever heard of disconnecting the battery for 30+ minutes after having a muffler installed to reset the computer so it can adjust to the new air flow?

 

[01ssreda4]

has anyone ever heard of disconnecting the battery for 30+ minutes after having a muffler installed to reset the computer so it can adjust to the new air flow?

Sure, that will reset your fuel trims, or you could just wait a few drive cycles and it will relearn them over time. Either will work.