# Duramax add ons?



## Dookie Ray (Apr 9, 2008)

I didnt' want to hijack redexpress' thread, so I'll start this one. What aftermarket add ons have some of you done to increas the fuel economy in your Duramax? I have a 2012 with the Allison auto tranny and 3:73 gears and I only get about 13-14mpg with mixed driving. I have heard someone say something about a programmer that "doesn't leave a footprint" and a cold air intake. Do any of you have anything like that, and does the performance change justify the expense? Please no "well my Ford or My Dodge" stuff, I'm just looking for a little help. Thanks

Dook


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## DSL_PWR (Jul 22, 2009)

All programming leaves footprints PERIOD. 

You might want to look at EFI live. That might give you the tuning you want. 

Cold air intake will not do any good. Stock air filter is best.


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## Gottagofishin (Dec 17, 2005)

A tune can help you pick up an mpg or two if you drive it the same as without a tune. Most people can't help but get a little more heavy footed with a tune though. My experience is that most late model vehicles have cold air intake systems already, so an aftermarket intake will only help if it improves airflow through the engine. To do so, also requires an upgrade to the exhaust system in most cases. Again, 1 mpg is about all you can expect in the real world. Economically, the cost of the upgrades will likely never be made up for in fuel savings. I tuned a 2000 SD 7.3 to maximize towing. Tune, new intake, and exhaust ran about $3500. I picked up 2 mpg in regular driving. It would pull a house off its foundation though.

The main issue is that you are driving an 8000lb truck designed to pull heavy loads. There is only so much you can do to improve the gas mileage. 

The best thing to do is practice fuel saving driving techniques, keep your tires properly inflated, and the drive train maintained and in good working order. Just my .02


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## Reynolds4 (Jan 18, 2010)

I have an 08 with around 93k miles and I just recently did away with the DPF and went with a MBRP 4" exhaust and EFILive tuner. My mileage increase was immediate. I typically would get 13.5 in town and 15.5 on the highway empty. Now I'm getting 16.5 in town and 19-20 on the highway depending in how heavy my foot is. I haven't pulled any distance yet but will be this upcoming hunting season. Wish I would've done it sooner because now I have the new truck bug.


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## 300 win mag (Nov 19, 2012)

EFILive tuning and turbo back pro flow exhuast system with muffler (or close to it). Cold air intakes might make just a little hp but does not justify the expense. Synthetic oil....Rock and Roll...
And yea I have a Dodge.
EFILive tuning is great!


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## theyallbreak (Jan 29, 2012)

RACER X said:


> EFILive tuning and turbo back pro flow exhuast system with muffler (or close to it). Cold air intakes might make just a little hp but does not justify the expense. Synthetic oil....Rock and Roll...
> And yea I have a Dodge.
> EFILive tuning is great!


Lucky you to have a 06 and up common rail im stuck with udc


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## goodwood (Mar 30, 2009)

If you have the small Chevy wheels, taller tires will make your gear ratio bigger.


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## loco4fishn (May 17, 2010)

My 06 lbz got 18+ mpg on the factory 245 size tire. I went to a 305 then 285 and now get about 13


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## goodwood (Mar 30, 2009)

305 and 285 is the width. you wanna stay narrow to decrease rolling resistance and unsprung weight.


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## 300 win mag (Nov 19, 2012)

305/70/17
305 is the sidewall height.
Your tread is 70% of that
17 is your wheel size.


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## 300 win mag (Nov 19, 2012)

I had it wrong...
305 width.
side wall is 70% of that... you know the rest..


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## shooter308 (Jul 31, 2013)

*duramax add ons*

h/s mini max pro flow 4" and s/b cold air u can see 20 -22 hwy do them all the time.


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## rglide09 (Mar 21, 2012)

On my 2002 Dmax I added MBRP 4" exhaust, Banks air intake system, Quadzilla programmer and run 265 tires. I didn't notice much if any fuel mileage gains with these mods but the turbo whine is much more noticable, no problem here with that! Seat of he pants performance is much better..........


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## BrandonH (Oct 15, 2006)

Mine is an '03 with an '05 lly engine. I have 4" exhaust all the way from the turbo back, pcv re-route, egr deleted, aftermarket air intake, and custom tuned on a dyno with efi live. My power was sonewhat limited due to factory transmission, so I had to settle on 410hp & 650ft lbs torque. I get around 18mpg averaging city and highway, I have gotten as hight as 21mpg with just highway miles.

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