Quest For Milage

uchi · November 4, 2010

im seeing alot of guys on here getting some respectable gas milage for a truck. i wanna see if i can get around the 450 mile to a tank club. ive added some air to my tires. dealership gave me the truck with about 32 psi in them, i bumped them up to 36 to see how it rides and affects milage and ive been driving it very gingerly. i went to the gym and back tonite with my tank full and the milage meter stayed around 19 mpg and didnt dip below 18.0 at all. it only dropped that low because of some hills that i tried to mostly coast up with mild throttle input. i start off very easily and im sure im pissing off people around me but i wanna see just how far i can stretch the gas in this thing and compare it normal driving to see how much of a difference it makes. id imagine itll be significant as ive seen it get to 11 mpg with some of my more normal driving. i just need to hit the hiways and get some hiway km on her to even out the mixture of city and hiway. so if anyone has any free or cheap tips for me please feel free to share. truck is an 06 slt sierra crew cab 4x4 with leather and power everything. not sure what it weighs but im sure its well over 5000 pounds. lol, so every little bit helps

plumber802 · November 12, 2010

You might get another .5 mpg with a tonneau.

pwall · November 13, 2010

Keep it at 55mph on the highway, it'll get the best mpg then. But then there's the risk of falling asleep at that speed.

Zembonez · November 13, 2010

Keep it at 55mph on the highway, it'll get the best mpg then. But then there's the risk of falling asleep at that speed.

Or getting run over. Nobody going much under 80 here normally.

Realistic fuel economy if you are good to these trucks is going to be 16-18 MPG. I suppose you could nudge that by a .2 here or there but you should be able to see 17 or a bit more pretty easily if you drive highway a bunch.

mtsusa · November 13, 2010

Yeah, driving habits will be your best bet. Driving conservatively I got about 1 mpg better with the addition of my magnaflow and airaid MIT and I'm getting a tune tomorrow, which should help...otherwise, it's all in how you drive. Try not to downshift on highway grades, keep RPMs as low as possible, gradually increase your speed, proper vehicle maintenance, etc. On a tank of 70 highway/30 city I pull a pleasing 22.1 mpgs.

oldscsc · November 13, 2010

I've managed 19.35 MPG in my truck (100% highway) but I have a regular cab 2WD 4.8 / 3.42 truck. What gears do you have? The RPO code will be in your glove box. GU4=3.08. GU6=3.42. GT4=3.73. GT5=4.10

Assuming you have a 3.73 gear ratio and 5.3 4x4, personally, I'd be very pleased with 17 MPG or above.

[email protected] · November 13, 2010

Maybe you ought to go and get an HHO generator and get 50 MPG while saving the planet man!!! But, seriously, I'd almost die to see my truck get 19(I get 12-13), so I say you're doing pretty good already.

b00001 · November 13, 2010

Yeah, driving habits will be your best bet. Driving conservatively I got about 1 mpg better with the addition of my magnaflow and airaid MIT and I'm getting a tune tomorrow, which should help...otherwise, it's all in how you drive. Try not to downshift on highway grades, keep RPMs as low as possible, gradually increase your speed, proper vehicle maintenance, etc. On a tank of 70 highway/30 city I pull a pleasing 22.1 mpgs.

Hey there Matt,

You saying you did 22.1 in a 4x4 on a full tank of gas or as you were cruising on the interstate and looked at the avg, you were getting 22.1 at that time???? If you are saying you got 22.1 on a full tank of driving, did you calculate that mileage or is that what the DIC said the mileage was???? My truck is just like yours except mine is a ext cab (lighter) and 4x2 (less drag) and the best I have done is a touch over 20 and that was 100% hwy on a dead flat stretch of over 400 miles.

Also, which tune are you getting and could you please give a review or two. I would love to hear your experience immediate after tune and say after a few tanks run though. SOP feel and fuel mileage. Be sure to calculate it, I have heard tunes do something to the DIC's ability to calculate the mileage. DIC is 10-15% off as is anyway!

Thanks!

Navaho · November 23, 2010

Hey there Matt,
You saying you did 22.1 in a 4x4 on a full tank of gas or as you were cruising on the interstate and looked at the avg, you were getting 22.1 at that time???? If you are saying you got 22.1 on a full tank of driving, did you calculate that mileage or is that what the DIC said the mileage was???? My truck is just like yours except mine is a ext cab (lighter) and 4x2 (less drag) and the best I have done is a touch over 20 and that was 100% hwy on a dead flat stretch of over 400 miles.

Also, which tune are you getting and could you please give a review or two. I would love to hear your experience immediate after tune and say after a few tanks run though. SOP feel and fuel mileage. Be sure to calculate it, I have heard tunes do something to the DIC's ability to calculate the mileage. DIC is 10-15% off as is anyway!

Thanks!

The Key to Accurate MPG's on the DIC is to Reset it to 0 at every Fill Up.

I keep very accurate mileage reports (for re-imbursement) and my manual MPG calculations are 100% to the DIC.

I have a 2007 Silverado Crew Cab 2WD, 5.3L w/AFM, and I average between 19.7 and 20.5 MPG's on a complete tank, living in Socal with a mix of Highway, Street and Traffic.

My One Way MPG High was 25.7, Driving 100% Highway from Los Angeles to Las Vegas.

Zembonez · November 23, 2010

DIC is NOT a reliable way to calculate fuel economy. It will indicate ridiculous (25.7) mileage figures on open highway but the truck is not actually getting that.

On several trips, I have reset mine and refilled my truck. Each time the DIC indicated between 18.5 and 19.0 MPG. When refilling and doing the actual calculations, the REAL MPG was in the 17.0 to 17.5 range. Anybody relying on CID mileage readouts is fooling themselves. Over several thousand miles the DIC is more accurate, but it sucks for single highway trip calculations.

ognob · November 24, 2010

I found that my driving habits alone have increased my MPG by 3-4 mpg. If I am really good I can get 22mpg, granted I have the 4.3l. From what I have found a steady easy throttle going up hills prevents downshifting and on a longer trip saves a good amount of gas. Any body have any good words about programmers?

peteking · November 24, 2010

Check your type of tire too. When I seasonally switch between my summer highway treads and my winter all-terrains...I tend to lose about 2 mpg on the highway.

lake357 · December 18, 2010

Has anyone tried a K&N cold air intake filter I was told ( not that I believe it) the it will increase the HP by 17 and therefore have more power to hold the afm in 4cyl mode longer and more often

TDImark · December 25, 2010

Some of these mileage posts are outrageously optimistic! Yeah, I get 55 mpg + as a coast down the Cajon Pass into Devore on the I-15 -- but, only under those unique AND time limited conditions.

kdixer · December 27, 2010

DIC is NOT a reliable way to calculate fuel economy. It will indicate ridiculous (25.7) mileage figures on open highway but the truck is not actually getting that.

On several trips, I have reset mine and refilled my truck. Each time the DIC indicated between 18.5 and 19.0 MPG. When refilling and doing the actual calculations, the REAL MPG was in the 17.0 to 17.5 range. Anybody relying on CID mileage readouts is fooling themselves. Over several thousand miles the DIC is more accurate, but it sucks for single highway trip calculations.

Not all DIC's have the same level of accuracy. I suspect it all depends on how well the "other" sensors on your vehicle are calibrated.

Every time I have checked mine it has been within .5 mpg for a tank of fuel. Clos enough for me since I simply use the DIC as a baseline, not the gold standard.