Poor gas milage

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Calman2k

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Good day!
My average mpg is around 13-14mpg. I have the Five Star tune for daily/tow 87 Octane and a cat back exhaust. I know I have bigger tires but seems like a lot of people on the forum are getting at least 18mpg.
Should I "try" to contact Five Star about this?
Is there anyone else getting the same mpg as my truck?

Thanks
You might be able to check and see if your speedometer is off. When driving on the freeway pull up your google maps and compare the GPS speed to the speedometer on your truck. If they don't match it could throw off your mileage.
 

Lou Hamilton

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You might be able to check and see if your speedometer is off. When driving on the freeway pull up your google maps and compare the GPS speed to the speedometer on your truck. If they don't match it could throw off your mileage.
I like the app Speedbox. Not sure if it available as Android, but it is available in the Apple App Store.
 

purevw

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Assuming the odometer reads from the wheel sensors or even any other sensor within the drive train, the odometer mileage will not be correct if you vary away from OE tire size. Someone stated 2mph per 1" of tire size. My pickup is off by 7mph by going only slightly larger than OE at highway speed. There are plenty of free calculators online where you can enter your OE and actual tire sizes and get an accurate estimate of the speed / odometer variation caused by the modification. If your odometer shows you traveled 200 miles, but you actually traveled 230, then there is no way the odometer can be used for mileage calculation. I can't speak for Apple products, but if you use Android, DigiHUD pro speedometer is a good digital gps speedometer / odometer, with full features. I use the paid version (3 or 4 bucks). It also gives you the option of placing your phone on your dash, to cause a heads-up display to be reflected off of your windshield, but I have concerns with leaving a cell phone in direct sunlight for long periods.
 

Pawpaw

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Checked my speed with one inch taller tires and GPS read 69 mph when dash showed 70 mph. Close enough for me!! Usually 2 mph less for every extra inch of height. Some factory speedometers show 2 mph higher than you're actually going.
 

1111ExpyEL1111

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It's a large SUV. I'm sorry but what did you expect? Best I've got on our 16 Expy is 20.1 highway at 55 mph and no AC. Normal highway 70 mph is right around 18. City is typically 15.
 
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JimW

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You might be able to check and see if your speedometer is off. When driving on the freeway pull up your google maps and compare the GPS speed to the speedometer on your truck. If they don't match it could throw off your mileage.
Yeah my speedo is off by 5mph so I Know that effects the milage a little also. 5 star was suppose to adjust the speedo but they can't get it right after multiple calls....

Of course, the tires effect the mph. I had 33's on my 07 Escalade with the 6.2 and had about the same mpg.

I do add fuel infector cleaner and octane booster from time to time to help. Today i have around 15.5 mph(driving easy) so after I adjust for the tires that would be around 18-19 mpg so I guess that's not bad with the larger tires. Thanks for the feedback!
 

Deep8174

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The expy is horrible in gas mileage around town. Hwy is decent, but in my geographic area and the way this city is hilly I average about 13 mpg as well.
 

Lou Hamilton

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The expy is horrible in gas mileage around town. Hwy is decent, but in my geographic area and the way this city is hilly I average about 13 mpg as well.
I get about the same in city as my previous 2011 Honda Pilot. Highway is about 2mpg less than the Pilot.
 

Fozzy

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Usually the tune is the problem, makes you want to put your foot in it more. But with 35ish tires that sounds about right. I average 13-14 combined with 35x12.50x20's driving it like gas is free.
 
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JimW

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Usually the tune is the problem, makes you want to put your foot in it more. But with 35ish tires that sounds about right. I average 13-14 combined with 35x12.50x20's driving it like gas is free.
Yea that's the problem driving it like gas is free...haha
 
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