Increase mpg - The 1947 - Present Chevrolet & GMC Truck Message Board Network

reesew · 02-07-2011, 08:19 PM

OK here is my question I want to get more than 16/gal out of my 2008 Silverado LS with 4.8. I thought of a power programer. Do they work? Asked my mechanic he says it wil fry my computer, dealer customer service says it will void my warrinty, Lots of questions anyone have any ad ice?

reesew · 02-07-2011, 08:20 PM

Oh I forgot I don't know how to use this site

blazerboy72 · 02-07-2011, 08:50 PM

You may want to look for a problem if you are only getting 16. I normally average 19-20 in mine, even my 4runner with a 5.3 and no overdrive gets 15.

71swb4x4 · 02-07-2011, 09:47 PM

Is that 16 in town or on the highway? Is that what you see year-round? I know my mileage suffers greatly in the winter because I am more apt to let me truck warm up, and also will leave it running sometimes when I run inside.

'72customdeluxe · 02-07-2011, 11:06 PM

Soft tonneau, lowering kit (might help on the highway), and a REAL tune. Forget the handheld. Look up Black Bear performance, Wheatley, or Nelson tuning. They do mail order tuning, but are starting to do handhelds with your stock and custom tune

STOCKISH · 02-07-2011, 11:24 PM

K&N FIPK intake. Made a HUGE difference on mine. I have a 07 Silverado classic crew cab 2wd. I get 17 around town and 20+ on the highway.

andrewmp6 · 02-08-2011, 07:51 AM

Is it a 4x4 does it have a lift or bigger then stock size tires?Driving habits can hurt your mpg also.My little test is drive the speed limit and use cruise control the max they will show you the max mpg your truck would get.

usmcchevy · 02-08-2011, 09:25 AM

Quote:

Originally Posted by '72customdeluxe

REAL tune. Forget the handheld. Look up Black Bear performance, Wheatley, or Nelson tuning. They do mail order tuning, but are starting to do handhelds with your stock and custom tune

What he said!!!!! you will not do any single thing that will benifit you more.

Shon · 02-08-2011, 04:57 PM

Quote:

Originally Posted by reesew

OK here is my question I want to get more than 16/gal out of my 2008 Silverado LS with 4.8. I thought of a power programer. Do they work? Asked my mechanic he says it wil fry my computer, dealer customer service says it will void my warrinty, Lots of questions anyone have any ad ice?

handheld will not do anything.
what fuel are you running?
how do you drive?
We have tuned several vehicles and gained 3% in MPGs.

69CST4x4SWB · 06-06-2012, 04:47 PM

Quote:

Originally Posted by reesew

OK here is my question I want to get more than 16/gal out of my 2008 Silverado LS with 4.8. I thought of a power programer. Do they work? Asked my mechanic he says it wil fry my computer, dealer customer service says it will void my warrinty, Lots of questions anyone have any ad ice?

WOW... I wish I had that problem... try 7 to 8 MPG!!!

**LEEVON** · 06-07-2012, 05:22 PM

What gears do you have? My 08 4.8L with 3.23's got that kind of mileage around town. Not enough gear...

Like the others said, go custom tune. Blackbear Performance, Google it. That's what I have on my 5.3L '08. I had the 4cyl mode turned off and still get 16-17mpg around town. Averaged 19.3 on a 500 mile trip recently.

Your dealership is right, PCM tune will void your warranty. You can purchase another computer to swap out with the original if you have to go in for service though. Oh.... and find another mechanic, yours has been breathing in too many exhaust fumes!!!

piecesparts · 07-10-2012, 04:45 PM

As stated above, I get 19 to 20 from my 5.3 with a set of 3.42 gears, in my 2011 SWB. I have put in an EFI Live upgrade on my engine tune and tightened up the shift points on the tranny. I have installed a Cold air intake and a set of Kooks headers to an exhaust that has a magnaflow muffler. I am running a 265/50/20 tire size. I have not lost any MPG, but I did not gain any either, I did gain a lot of torque with the headers.

I have a local tuner guy that is big into the Gen III and GenIV engines.

timcrow00 · 10-11-2012, 04:48 PM

i was always told by dealer techs that you cant do anything to void your warranty completely. only if they can trace the problem directly to a modification that your have made will it no longer be covered under warranty

clinebarger · 10-12-2012, 09:40 PM

Modifying the ECM/TCM calibration WILL void the powertrain warranty, Yes they will know

piecesparts · 10-18-2012, 07:14 PM

Quote:

Originally Posted by clinebarger

Modifying the ECM/TCM calibration WILL void the powertrain warranty, Yes they will know

I was good with that, when I did mine. I am not sorry either. Runs great and worth every penny.

clinebarger · 10-18-2012, 07:45 PM

Quote:

Originally Posted by piecesparts

I was good with that, when I did mine. I am not sorry either. Runs great and worth every penny.

Thats cool, Some people will do this & not realize that they are now their own warranty station. Then Cry when their trans breaks.

02-07-2011, 08:19 PM	#1
reesew Registered User Join Date: Feb 2011 Location: dewitt iowa Posts: 7	Increase mpg OK here is my question I want to get more than 16/gal out of my 2008 Silverado LS with 4.8. I thought of a power programer. Do they work? Asked my mechanic he says it wil fry my computer, dealer customer service says it will void my warrinty, Lots of questions anyone have any ad ice?

02-07-2011, 08:20 PM	#2
reesew Registered User Join Date: Feb 2011 Location: dewitt iowa Posts: 7	Re: Increase mpg Oh I forgot I don't know how to use this site

02-07-2011, 08:50 PM	#3
blazerboy72 Senior Member Join Date: Mar 2002 Location: Temple, Ga Posts: 854	Re: Increase mpg You may want to look for a problem if you are only getting 16. I normally average 19-20 in mine, even my 4runner with a 5.3 and no overdrive gets 15.

02-07-2011, 09:47 PM	#4
71swb4x4 Senior Member Join Date: Nov 2003 Location: Brookings, SD Posts: 10,497	Re: Increase mpg Is that 16 in town or on the highway? Is that what you see year-round? I know my mileage suffers greatly in the winter because I am more apt to let me truck warm up, and also will leave it running sometimes when I run inside. __________________ Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs.

02-07-2011, 11:06 PM	#5
'72customdeluxe Registered User Join Date: Jan 2008 Location: Tejas Posts: 691	Re: Increase mpg Soft tonneau, lowering kit (might help on the highway), and a REAL tune. Forget the handheld. Look up Black Bear performance, Wheatley, or Nelson tuning. They do mail order tuning, but are starting to do handhelds with your stock and custom tune __________________ '72 cheyenne super step, '05 long bed gmc

02-07-2011, 11:24 PM	#6
STOCKISH Formerly- 1972SuperCheyenne Join Date: Oct 2008 Location: Wake Forest NC Posts: 5,782	Re: Increase mpg K&N FIPK intake. Made a HUGE difference on mine. I have a 07 Silverado classic crew cab 2wd. I get 17 around town and 20+ on the highway. __________________ --Josh My Build Thread:http://67-72chevytrucks.com/vboard/s...d.php?t=799218 A good crossthread is better than Loctite any day. Life is not about what you have, but who you have to share it with.

02-08-2011, 07:51 AM	#7
andrewmp6 Registered User Join Date: Jan 2009 Location: Louisville,Ky Posts: 5,811	Re: Increase mpg Is it a 4x4 does it have a lift or bigger then stock size tires?Driving habits can hurt your mpg also.My little test is drive the speed limit and use cruise control the max they will show you the max mpg your truck would get.

06-07-2012, 05:22 PM	#11
LEEVON Registered User Join Date: Jul 2006 Location: Ozark, MO Posts: 4,887	Re: Increase mpg What gears do you have? My 08 4.8L with 3.23's got that kind of mileage around town. Not enough gear... Like the others said, go custom tune. Blackbear Performance, Google it. That's what I have on my 5.3L '08. I had the 4cyl mode turned off and still get 16-17mpg around town. Averaged 19.3 on a 500 mile trip recently. Your dealership is right, PCM tune will void your warranty. You can purchase another computer to swap out with the original if you have to go in for service though. Oh.... and find another mechanic, yours has been breathing in too many exhaust fumes!!! __________________ '20 Silverado Trail Boss ~ '17 Tahoe ~ '79 K15 Sierra Grande ~ '76 Blazer 2wd ~ '71 Cheyenne swb ~ '55 Pontiac Safari ~'50 3100 bagged ~ '80 Wife ~ Late model kids

07-10-2012, 04:45 PM	#12
piecesparts Parts and more parts Join Date: Nov 2003 Location: Lebo, Kansas (middle of nowhere Posts: 6,821	Re: Increase mpg As stated above, I get 19 to 20 from my 5.3 with a set of 3.42 gears, in my 2011 SWB. I have put in an EFI Live upgrade on my engine tune and tightened up the shift points on the tranny. I have installed a Cold air intake and a set of Kooks headers to an exhaust that has a magnaflow muffler. I am running a 265/50/20 tire size. I have not lost any MPG, but I did not gain any either, I did gain a lot of torque with the headers. I have a local tuner guy that is big into the Gen III and GenIV engines. __________________ Frank

10-11-2012, 04:48 PM	#13
timcrow00 Registered User Join Date: Mar 2009 Location: mulvane, KS Posts: 200	Re: Increase mpg i was always told by dealer techs that you cant do anything to void your warranty completely. only if they can trace the problem directly to a modification that your have made will it no longer be covered under warranty

10-12-2012, 09:40 PM	#14
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: Increase mpg Modifying the ECM/TCM calibration WILL void the powertrain warranty, Yes they will know



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