Causes of negative gas mileage

Hi all, new to the tundra platform. I have a 2015 limited TRD tundra. I just installed a flowmaster super 44 dual exhaust system as well as a trd cold air intake. Before installing those items the gas milage was as normal as a 2.5 gen tundra would be. However now, going off the belief that trd intakes sort of help with gas mileage, I'm sure not in everyone's case, I notice a more than significant decrease in gas mileage. It'll drop at least 1 digit on the "miles to empty" gauge in probably a mile or less depending on how I drive/take off. It's stock height, my tire size is only 285, wheels are only a 20 inch, no weight is in my bed, I just had my vehicle serviced and nothing is wrong with it. I was thinking it could be the weight of the dual exhaust system but that sounds ridiculous. Any body experience something similar or have any input on maybe whether keeping the trd intake or switching back to original.
Thanks!

 

Hand calculate it and get back to us. Mine with a turbo and tuning has the range showing 600 miles but I’m doing good to get 400.

 

Couple things possibly going on here....

First, is that when we put a new exhaust system on a vehicle, we like to hear it roar. So, a heavier pedal (even if it's unintentional) will usually result in a reduction in MPG.

Secondly, dual exhaust set ups (even the Pro's TRD exhaust) have shown cause a decrease in low end torque on our rigs. The reduction in torque will generally result in a heavier pedal as well to make up for the torque reduction as you try to maintain similar performance w/the new system which will also net a drop in MPG.

Third, the factory intake is also 'cold air' and so the addition of the TRD CAI will probably provide no benefit in terms of mileage or performance. Although many say they enjoy how it sounds after installation.

PS>>> Welcome to the forum!!!

 

Ok. Yeah, I highly noticed that with the slight pedal force that's needed when driving. I also searched if there's solutions or fixes and I seen that you can possibly have the vehicle tuned? You know if that's accurate at all?

 

Take a look in this thread. I believe they talked about MPGs, etc. w/the OTT tune....

Is the OTT Tune Right For Me?

 

I know you just installed it, but Keith with @dirtydeeds is an awesome guy. He can give you so much info for your exhaust, and even help you out. But based on what he told me, yes, a dual exhaust will decrease MPG.

 

You get the best mileage stock, anything you do is only going to reduce that mileage.

285s definitely aren’t helping anything. What wheels and tires are you running? 100lbs combos on each corner of the truck only drag you down…