Unbeleivable & Unexpainable Highway Mileage
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CF Beginner
Joined: Sep 2015
Posts: 1
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From: Franklin, Wisconsin
Unbeleivable & Unexpainable Highway Mileage
Bought a used 2006 Silverado 1500LT 4x4 Crew Cab 5.3 engine, 3.42 differential with 80,000 miles. Drove it for 5 or 6 years and was very pleased with consistent highway mileage of 20 to 21 with an occasional 22 mpg. I have a very light weight "Feather Foot".
Decided to trade it in at about 117,000 miles on a very clean 2012 Silverado 1500 4x4 Crew Cab 5.3 engine, 3.42 differential that had about 60,000 miles. Love the truck, but HATE the crappy economy! Just got back from a 1200 mile trip to Canada and back. 99.9% Interstate highway miles the majority of which was between 55 mph and 65 mph with only about 100 miles or so at 70 mph. The overall mileage calculated at 17.217 mpg and the electronic reading on the truck read 17.2; virtually identical.
Both trucks have the same engine (5.3) and differential (3.42.) Only differences are the 2012 has a 6-speed transmission, flex fuel (NEVER used), and the Energy Management System (V8-V4). And I still have the same "Feather Foot"
I HATE IT ! ! ! All of the other miles than the Canada trip are virtually IDENTICAL as the 2006. I use the same gas, from the same gas stations, travel the same interstate highways. Cold tire pressure is recommended at 35 psi. I consistently maintain 35 to 36 psi because I do so much highway driving.
I love the truck but can't afford to drive it! 6-speed?, Energy Management?. Is General Motors going "Backwards" ? ? ? I'm NOT a happy, loyal GM Customer.
Decided to trade it in at about 117,000 miles on a very clean 2012 Silverado 1500 4x4 Crew Cab 5.3 engine, 3.42 differential that had about 60,000 miles. Love the truck, but HATE the crappy economy! Just got back from a 1200 mile trip to Canada and back. 99.9% Interstate highway miles the majority of which was between 55 mph and 65 mph with only about 100 miles or so at 70 mph. The overall mileage calculated at 17.217 mpg and the electronic reading on the truck read 17.2; virtually identical.
Both trucks have the same engine (5.3) and differential (3.42.) Only differences are the 2012 has a 6-speed transmission, flex fuel (NEVER used), and the Energy Management System (V8-V4). And I still have the same "Feather Foot"
I HATE IT ! ! ! All of the other miles than the Canada trip are virtually IDENTICAL as the 2006. I use the same gas, from the same gas stations, travel the same interstate highways. Cold tire pressure is recommended at 35 psi. I consistently maintain 35 to 36 psi because I do so much highway driving.
I love the truck but can't afford to drive it! 6-speed?, Energy Management?. Is General Motors going "Backwards" ? ? ? I'm NOT a happy, loyal GM Customer.
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Joined: Jul 2009
Posts: 2,197
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From: Highlands
The 6 speed and the 4 speed have roughly the same overdrive ratio so rpms should be the same especially havin same gears. Difference could be weight and the fact that the 07-13s are like bricks goin down the highway. Other variables affect mpg obviously. Wind speed and what not, so those do have to be taken into affect. Every truck is different, my 2014 z71 4x4 6.2 gets 17-18 mpg overall, and 20-22 hwy while my old 2008 2wd regular cab 4.8 got 16 -18 hwy
