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V6 to GT: Whoa, why didn't my mileage drop?

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Old 06-19-2014, 12:47 PM   #1
GTC
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Default V6 to GT: Whoa, why didn't my mileage drop?

I traded a 2013 V6 Premium Auto with Pony Package (18" Tires) for a '14 GT Auto (19" Tires).

The GT gets about 3mpg less on the highway (25 compared with 28/29) than the V6.

But, I traded the V6 with 26,734 miles, and the average mpg for that period is 22.2mpg.* The GT, which if anything I'm driving a little faster, particularly from a stop, has gotten 23.2mpg with the odometer at 812 (it was delivered with over 300), and I was fully expecting 19mpg! So this is good yet mysterious.

*The computer mileage on the V6 tended to be about .7 lower than actual. So, maybe closer to 22.9 actual mpg. I don't know if the GT's computer leans wrong in either direction or is spot on.
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Last edited by GTC; 06-19-2014 at 12:51 PM.
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Old 06-19-2014, 01:00 PM   #2
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what axle?
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Old 06-19-2014, 01:26 PM   #3
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Originally Posted by jz78817 View Post
what axle?
Both being automatics, the standard GT has 3.15:1, and I believe the V6 had the same since the only package it had was the Pony Package which doesn't change the rear end.
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Old 06-19-2014, 01:27 PM   #4
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I get roughly 26-29 mpg on the highway with 3.73 gears. If I draft I break 30

If I drive to fast (above 65) it's looking closer to 24 mpg
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Old 06-19-2014, 01:55 PM   #5
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If I drive to fast (above 65) it's looking closer to 24 mpg
65?!?! If you go 65 around here you will get run over by pickups and hondas. I do 80 on the local interstates. I also have 3.73 gears and get around 18-19mpg if I drive "normal". If I take it easy I can get 22-23, still doing 75 or so.
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Old 06-19-2014, 09:03 PM   #6
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My non stock 2011 GT gets 27-29 at 60 depending on hills and outside temp.
I average 24-25.

ETA:7-2-14 pulled into the driveway today with a 27.1 avg.

My GT 500 14-15
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Old 06-20-2014, 10:40 AM   #7
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I dont ever look at the computer generated gas mileage, I use it more as a reference cause not too sure how accurate it is anyway, but if I worried about gas mileage I would have bought a Prius.
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Old 06-20-2014, 10:45 AM   #8
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v6 and v8 are so close on mpg it dont matter...
i get 1 litre per 10 kilometers in my 4.6..about 25mpg..my v6 did about 26-27 mpg
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Old 06-20-2014, 11:13 AM   #9
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Quote:
Originally Posted by dcarlinf1 View Post
65?!?! If you go 65 around here you will get run over by pickups and hondas. I do 80 on the local interstates. I also have 3.73 gears and get around 18-19mpg if I drive "normal". If I take it easy I can get 22-23, still doing 75 or so.
I know lol. In in SoCal and everyone drives wicked fast. I have learned to drive in the number 3 or 4 lane slow and generally have more run in with sweet cars. Just my thoughts lol, and at 80mph I avg 24mpg
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Old 06-20-2014, 11:14 AM   #10
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It has to do with power to weight. The V6 is moving roughly the same weight as the V8 with less power, therefore it has to work harder. This is why they get roughly the same fuel mileage, even though the V6 engine is technically more efficient than the V8.
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Old 06-20-2014, 01:17 PM   #11
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With the right body shape, a car only needs a few HP to cruise at hwy speed. Speed changes and the occasional naughtiness probably account for most of the difference.
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Old 06-29-2014, 07:02 PM   #12
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The Coyote is very surprisingly a fuel miser, often getting above the advertised 26MPG on the freeway at 70MPH.
I attribute that to the very high 11:1 CR and the TiVCT which goes into a fuel saving cam timing during cruising.
Even in bumper to bumper rush hour traffic with speeds crawling as low as 20MPH and many dead stops and go's, at the end of the week, my AVG MPG is still above 20MPG. My AVG MPG read is 20.7MPG right now as we speak.
On the freeway, I have driven 100mi on a relatively flat freeway at a steady 70MPH and regularly hit 28MPG AVG and with good a tailwind, as much as 30MPG.

If I hit the reset and begin clocking my AVG MPG only for the parts that I am cruising at 70MPH, I see it reading over 30MPG AVG for the 70MPH leg of the trip; these legs lasting as long as over 70 miles and my AVG MPG never drops below 30MPG.

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Old 06-29-2014, 10:23 PM   #13
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My 2011 5.0 M6 averaged ~22mpg NA in the city and it averages over 24mpg with the ProCharger! It's pretty economical for a 10-second car!
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Old 07-28-2014, 12:55 AM   #14
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GTC, I just did the same thing! Traded my 2013 V-6 Premium for a 2014 GT. I averaged 24-26 to work in the V-6. While I have almost 500 miles on my GT, my 2 half tank fill-ups, I averaged 22.6 and 23.3. That is calculated mileage, not gauge. Haven't taken a trip yet in the GT, but I averaged 30-33 hwy with the 6. I'm sure if I drove it like I stole it the mileage would be lower, but gas is too high. I'm sure after my break-in I'll have fun with it though.
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Old 07-28-2014, 08:14 AM   #15
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4,700 miles on GT now, 21.2 mpg overall. 23mpg recently on 200 mile trip at average 85 mph and 97 degree ambient temperature (even with additional Ford oil cooler the oil ran just a wee bit warmer than usual but needle still centered on gauge nowhere near yellow); 25.4 mpg on return leg at 72mph and 8 degrees cooler ambient temperature.

Get about 1.7 mpg less overall than V6, and 4mpg less on highway, but drive the GT a little quicker, and I tend to make myself grin on on-ramps by punching it in 3rd gear.

Interestingly, with cruise control on going up fairly steep interstate grades the GT never downshifts out of 6th gear (Auto Transmission obviously). The same stretch of interstate would have the V6 dropping from 6th to 4th gear four or five times. So the GT is leaving highway mileage on the table by not having a taller additional 7th gear to shed some rpm and take advantage of the Coyote's power.

Can't really see the 2015 GT having a big mpg jump since they stayed with six gears unless they've reduced friction dramatically and are doing cylinder management (just firing needed cylinders depending on demand). Ford is saying the new GT burns fuel more efficiently. Would love to see another 4mpg overall. And, Would love to see an 8 speed auto with a dual clutch (e.g. new Acura TLX V6 has a 9 speed auto) and Ford and GM are jointly developing some of those boxes for the future.

Last edited by GTC; 07-28-2014 at 08:38 AM.
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Old 07-28-2014, 08:14 AM
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