There's a nice comparison of the Eco Boost 2.7, Chevy 5.3 and Fiat 3.0 in here....short version is the 3.0 crushed them in fuel efficiency by over 20% in real-world testing (even though the 2.7 was in a truck that weighed 1,000lbs less).
Comparison: 2015 Ford F-150 vs. Ram 1500 vs. Chevrolet Silverado All Pages
Don't know where you dreamed up 20%. The Dodge diesel costs $1500 more in fuel over five years to drive the same distance as the gas trucks.
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2015 GMC Sierra K15 4WD
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2015 Ford F150 Pickup 4WD FFV
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2015 Ram 1500 4WD
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4.3 L, 6 cyl, Automatic 6-spd 3.5 L, 6 cyl, Automatic 6-spd 3.0 L, 6 cyl, Automatic 8-spd, Turbo
MSRP: $30,545 - $58,475 MSRP: $30,065 - $54,680 MSRP: $29,520 - $52,875
EPA Fuel Economy
Regular Gasoline Regular Gasoline Diesel
Combined MPG:19 MPG
City MPG:17 Highway MPG:22
combined
city/highway city highway
Combined MPG:19 MPG
City MPG:17 Highway MPG:23
combined
city/highway city highway
Combined MPG:22 MPG
City MPG:19 Highway MPG:27
combined
city/highway city highway
5.3 gal/100mi 5.3 gal/100mi 4.5 gal/100mi
EPA range: 494 - 646 miles
494 - 646 miles
Total Range
EPA range: 437 - 684 miles
437 - 684 miles
Total Range
E85 E85
Combined MPG:13 MPG
City MPG:12 Highway MPG:15
combined
city/highway city highway
Combined MPG:14 MPG
City MPG:13 Highway MPG:17
combined
city/highway city highway
7.7 gal/100mi 7.1 gal/100mi
EPA range: 338 - 442 miles
338 - 442 miles
Total Range
EPA range: 322 - 504 miles
322 - 504 miles
Total Range
Unofficial MPG Estimates from Vehicle Owners
Learn more about "My MPG"
Disclaimer
User MPG estimates are not yet available for this vehicle
User MPG estimates are not yet available for this vehicle
User MPG estimates are not yet available for this vehicle
You save or spend*
Note: The average 2015 vehicle
gets 24 MPG
You SPEND
$1,750
more in fuel costs over 5 years
compared to the
average new vehicle
You SPEND
$1,750
more in fuel costs over 5 years
compared to the
average new vehicle
You SPEND
$3,250
more in fuel costs over 5 years
compared to the
average new vehicle
Annual Fuel Cost* Gas: $1,650 Gas: $1,650 $1,950
E85: $3,750 E85: $3,450
Cost to Drive 25 Miles Gas: $2.72 Gas: $2.72 $3.22
E85: $6.21 E85: $5.77
Cost to Fill the Tank Gas: $54-$70 Gas: $48-$75
E85: $84-$110 E85: $74-$116
Tank Size 26.0-34.0 gallons 23.0-36.0 gallons
*Based on 45% highway, 55% city driving, 15,000 annual miles and current fuel prices. Personalize. Five year cost savings for flexible fuel vehicles assume you drive on gasoline only.