exhaust... how much does it increase gas mileage????

[SapperRyash]

im looking to get some custom exhaust on my 2001. i want to do "dual" from what i have been told, it has to be a single inlet, dual outlet. is that true? if so, what is the increase on gas mileage? what is the best kit to go with? magnaflow, flowmaster, ect? and what have you paid? help me out please guys.

 

[SapperRyash]

wtf? nobody wants to help me out with this one?

 

[JKmotorsports]

Unless you go custom, you'll have to settle with the single in, dual exit pre-fab systems, as offered by companies like Flowmaster, Gibson, and Magnaflow. If you want a true dual, you'll have to go custom, routing the exhaust down side by side on the passenger side then split after the rear axle.
Your mpg increase will depend on the actual system and any other mods you may have. By itself, maybe a mile or so.

 

[boostaholic]

Mine dropped, maybe because the tach hovers around 5k too much :smilielol: But in all seriousness you'll see maybe 1mpg change, the biggest difference for mileage and power will come from a custom pcm tune although I did make some good power from the magnaflow I installed on the denali. I bought it at my work for $300.

 

[suckercyou]

pcm tune and everything else

what is the cost of a pcm tune I'm trying to get my denali in order im going to pick it up on friday im getting the 24's put on it on tuesday and still trying to find a shop to lower it, thinking about a JBA EXHAUST and Volant Intake. Let me know what you think EVERYTHING HELPS.

Thanks guys

 

[EZStreet]

I ran a flowmaster force II 50 Series on My 4.8 liter Yukon and I've seen an increase of about 2mpg (Once I stopped mashing the gas pedal). Most of my driving is highway, but my avg MPG jumped from about 14 to 15.8-16. So not great, but it sounds much better and I'll take 2mpg over nothing any day.

 

[mike1951]

My buddy is a big chevy guy and an ase master mechanic...we had this discussion.. to go the custom route with a true dual exhaust is not worth the money you will put into it...IMHO the single in and dual out is the way to go...
the reprogram on the computer will help as well..
good luck man..