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I recently made some mods to fit 35" tires on my 2012 ram 1500 that are real aggressive looking. Obviously because it looks great, but now I have taken a hit in the MPG range and have dropped from 15.2 mpg to about 13.6. I was wondering if anybody had any suggestions about a programmer, intake, or exhaust that might give me the best benefits to make up for the mpg lost.
 

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I too put 35's on my truck for the look and because I do off-road. I nstalled a CAI and put the Magnaflow exhaust on the truck, I have a tuner because it is a 2010 but don't think that will help with the MPG. I doubt you can get back all your miliage but it will help a bit. I don't calculate my MPG as I am afraid to know. I will mention that I run 91 octane all the time and it makes a big difference on MPG on the highway only.
 

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Maybe if you replace the factory Y pipe and some shorty headers combined with a CAI it may gain you 1 or 2 MPG. Once i lowerd my 11 with 24's i just changed the factory y and added a flowmaster 10 series i saw a gain from 17 to 19.5. Even on my last trip to houston i avg 20.8 running 75 to 85 mph.
 

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If you are looking at the EVIC MPG you need to be aware that it is calibrated for your stock tire size. Going to a larger diameter tire you will actually be going a bit further with each revolution (your speedo will be off a bit too) but your EVIC doesn't know this. If your stock tires were the 33's when your speedo reads 70 your are really doing 74. In a nutshell, you are going further than your odometer says you are. You do lose a little mileage due to the tires being heavier (weight penalty) but it isn't that much. Try doing a manual calculation correcting for the size difference. Your ECM can only be programmed for up to a 33" tire so no help from the dealer on this. You could add an aftermarket box (like a Hypertech) to correct but it really isn't worth it.
 

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If you are looking at the EVIC MPG you need to be aware that it is calibrated for your stock tire size. Going to a larger diameter tire you will actually be going a bit further with each revolution (your speedo will be off a bit too) but your EVIC doesn't know this. If your stock tires were the 33's when your speedo reads 70 your are really doing 74. In a nutshell, you are going further than your odometer says you are. You do lose a little mileage due to the tires being heavier (weight penalty) but it isn't that much. Try doing a manual calculation correcting for the size difference. Your ECM can only be programmed for up to a 33" tire so no help from the dealer on this. You could add an aftermarket box (like a Hypertech) to correct but it really isn't worth it.
Sooo true try comparing gps miles with your odometer then refigure your gas mileage with the actual gps miles. How about some pics with them bad boys on?
 

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MPG's !!!!!!!

I'm not sure why there is such a discrepancy in the MPG's on these trucks. For instants, I drive my 2012 w/392's almost 800 miles to work every two weeks, & at interstate speeds ( 75 avg ) I get 17.3 to 18.2 mpg depending on the geographical location. I did add a 180 T-stat, a Varraram Intake (which btw I would recommend to anyone in search of a CAI ) & I have a BT Catchcan that I've yet to install, but even totally stock, I was averaging almost 17 mpg at the same speeds. I do run only 91+ octane however, & all AMS synthetics this could possibly be the difference. I'm a firm believer that " Good In = Good Out "
 

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I'm also very interested to start improving the fuel economy in my truck...

My first truck was a 2005 RAM 1500 w/ 5.7L Hemi and an automatic transmission w/o mods, and the fuel economy balanced out at ~14.6 L/100km (~16.11 miles/US gal.).

Liked it so much, I traded it in for my current 2011 RAM 1500 w/ 5.7L Hemi Sport. The fuel efficiency sucks!! (pun intended!) Same traffic routine, I baby the throttle to keep it at 16 L/100 km/h (14.7 miles/US gal.) I wasn't so good at feathering the throttle with my first Hemi!! ;)

And here I thought that the new ECO mode would obviously give me increased fuel mileage! :doh:

Last summer on a pure highway trip from Calgary to Sicamous B.C., I was able to achieve 12.5 L/100km (18.81 miles/US Gal.) which is not bad, but not as good as some of the results I've seen here that makes me envious...(Grubrunner's photo from S&B CAI review)

So, now I'm looking to start modding to improve things--but--isn't there an issue with aftermarket modifications voiding warranty coverage?
 

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With mine I have found the the mds to be worthless in town, 14 mpg avg.. I get better mpg's in town limiting the tranny to 5th gear. The mds requires too much throttle input for in town driving. On the Highway the mds shines. I have gotten 22mpg running a steady 70-75 on fairly flat interstate, even seen 24mpg at 65mph. I ran 80-85mph from Florida to S.C. and averaged 17.8mpg's, all this was done running 87 octane with the a/c running constantly. My truck is still bone stock unfortunately.
 

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With mine I have found the the mds to be worthless in town, 14 mpg avg.. I get better mpg's in town limiting the tranny to 5th gear. The mds requires too much throttle input for in town driving. On the Highway the mds shines. I have gotten 22mpg running a steady 70-75 on fairly flat interstate, even seen 24mpg at 65mph. I ran 80-85mph from Florida to S.C. and averaged 17.8mpg's, all this was done running 87 octane with the a/c running constantly. My truck is still bone stock unfortunately.
Forgive the question, Im still new at all this...it looks like we have the same truck and correct me if Im wrong but you limit the tranny to 5th gear around town and leave it open for highway driving?
Thanks
 

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With mine I have found the the mds to be worthless in town, 14 mpg avg.. I get better mpg's in town limiting the tranny to 5th gear. The mds requires too much throttle input for in town driving. On the Highway the mds shines. I have gotten 22mpg running a steady 70-75 on fairly flat interstate, even seen 24mpg at 65mph. I ran 80-85mph from Florida to S.C. and averaged 17.8mpg's, all this was done running 87 octane with the a/c running constantly. My truck is still bone stock unfortunately.
Forgive the question, Im still new at all this...it looks like we have the same truck and correct me if Im wrong but you limit the tranny to 5th gear around town and leave it open for highway driving?
Thanks
+1!! 22 MPG on stock would be a dream!
 

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As I posted elsewhere, I checked and replaced the air filter (I know, I know... where to look if you've got poor performance and fuel economy) before I went on my annual summer vacation to British Columbia.

What a difference! My wife drove it out, and used the cruise control liberally as she wanted to take care of my baby. 20.5MPG!

I drove the return trip and managed to keep it to 20.3--the truck is all stock.

I find it frustrating that I take it in to the dealer for service, complain about performance and fuel economy, only to find that the air filter was pitch black on my own!! :4-dontknow:
 

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11.8 mpg here...would kill to have yalls 4th gen mpg
 

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11.8 mpg here...would kill to have yalls 4th gen mpg
Hmm... I used to average just a hair over 16 mpg in my '05... are you sure that your (relatively) low mileage isn't being caused by a heavy foot?

20.5 mpg highway is the best I've done with my 4th gen, and it's definitely being conservative with the pedal! ;)
 

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Hmm... I used to average just a hair over 16 mpg in my '05... are you sure that your (relatively) low mileage isn't being caused by a heavy foot?

20.5 mpg highway is the best I've done with my 4th gen, and it's definitely being conservative with the pedal! ;)
for the most part yes. but i will admit i do get on it but not floor it, ill just give it a little gas to hear it better. i am going to buy an intake end of this month, hopefully that helps.
 

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Ya, my 3rd gen also only gets around 13, but I have seen up close to 20 when my muffler was rusted out, and drove 60 with cruise :LOL:
 
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