2011 Gmc Sierra 1500 5.3 4x4 3.42 Axle

Horsewithnoname · April 13, 2011

New to the group and GMC trucks, was a ford guy in the past.

I have 1100 miles on the truck and my fuel economy on the last tank was 11.3 MPG mostly city with some freeway driving, a far cry from the 15 city and 21 freeway on the EPA sticker.

What should I expect for city and highway fuel economy?

Would a K&N filter help with my fuel economy?

Any suggestions, or is this just the way it is

old-chevy-dude · April 13, 2011

takes about 5,000 miles to break in..

I saw similar mpg when mine was new, my mpg started to climb and settle around 7,000 miles. I am at 19.4mpg avg city/hwy combined, and have seen has high as 24mpg on an extended trip in my 5.3L Avalanche with 3.42 gears.

also depends on your area (hilly/flat, etc), quality of gas, and your driving habits (slow starts or jack rabbiting to lights).

I'm a miser, I drive 60 - 65mph on the highway in the old fart lane, I accel VERY slow, and set the cruise control every chance I have to maintain a constant speed. I pull between 580 and 700 miles per tank.

I'll tell you, city driving will kill your MPG if you are a red light to red light racer.. slow and easy and coast when you see a stale green or red light ahead, racing to that red light is gonna burn fuel.. Also I have noticed about a 1.5 to 2 mpg change just by turning of the Auto HVAC.. keep it set at 75 with the A/C off and it will raise your MPG.. in Auto mode the A/C is constantly on/off/on/off.

chev1guy · April 13, 2011

It should get better as you brake it in. I currently get around 17.5 city/hwy.

Horsewithnoname · April 14, 2011

Thanks for the input...

TheGreekIndian · April 14, 2011

look up hypermilling tips. Things like coasting to a stop light and anticipating stops will help out alot. I average 16.5 MPG city by doing multiple different things and driving like I am 80 years old. every penny counts!

cujo8 · April 14, 2011

I also have a 2011 Sierra EC 1500 5.3L 4x4 w/ 3.42 gears and my milage is just a little higher than yours at ~1300. My daily commute to work and back is approximately 50 miles and 85% highway (Not very hilly around here). I got 18.5MPG on my last tank according to the DIC, but I've been trying to go easy on the gas and use the cruise control with my highway speed at ~ 60mph. I started out getting ~ 16.5mpg, so I believe the milage is improving, but I also maybe getting the summer blend gas now, so I'm not totally sure.

gnet158 · April 15, 2011

Lead foot here, I was getting 14.5 with a 50-50 mix. The must of switch to summer blend because I'm getting 15.1 / 15.3 on the last two tanks, same commute. This is with a tune and CAI.

HawkScot · April 15, 2011

I also have a 2011 Sierra EC 1500 5.3L 4x4 w/ 3.42 gears and my milage is just a little higher than yours at ~1300. My daily commute to work and back is approximately 50 miles and 85% highway (Not very hilly around here). I got 18.5MPG on my last tank according to the DIC, but I've been trying to go easy on the gas and use the cruise control with my highway speed at ~ 60mph. I started out getting ~ 16.5mpg, so I believe the milage is improving, but I also maybe getting the summer blend gas now, so I'm not totally sure.

Your mileage is improving because you have installed the pcv oil catch can!

cujo8 · April 15, 2011

I also have a 2011 Sierra EC 1500 5.3L 4x4 w/ 3.42 gears and my milage is just a little higher than yours at ~1300. My daily commute to work and back is approximately 50 miles and 85% highway (Not very hilly around here). I got 18.5MPG on my last tank according to the DIC, but I've been trying to go easy on the gas and use the cruise control with my highway speed at ~ 60mph. I started out getting ~ 16.5mpg, so I believe the milage is improving, but I also maybe getting the summer blend gas now, so I'm not totally sure.

Your mileage is improving because you have installed the pcv oil catch can!

That's really hard to prove, since my truck only has ~1300 miles on it and the milage is supposed to get better as the engine breaks in, but I'm really not sure how many miles this supposed to take. The other factor to consider is the switch from winter to summer blend fuel should be happening now. To see if the Oil Catch can mod improves MPG, someone with a more established MPG history that has installed this same mod will have to check this theory, but here's hoping.

denbadax · April 17, 2011

ive got a 2011 1500 with the 5.3 3.42 4x4 exsb ive got just over 4,000 on my truck i drive 60 miles daily to work hilly drive. on the dic it says 15.8 i did it out once and got 17.25 that was on a little further tri\p but not highway. what is the oil catch can mod?