6.7 cummins with 35's mpg

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ramguy11

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I have a 2013 ram 2500....
I had it bone stock up until 3 days ago.

I was getting around 20mpg at 85mph on the highway.
And 17-18 around town.

I had 33's with 20's put on 3 days ago and my mileage has went to complete crap.

13-14 around town and lucky to see 18-19 at 65.
15 at 75

I wanted to get it leveled and have 35's but was worried about mileage. The 33's killed it anyway so I'm about to just say screw it and do what I wanted from the get go.

But it wanted to ask here first.

What are any of you getting with 35's leveled or stock height with factory power levels and no deletes.

This is it with the 33's and Un-leveled.

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Stangshcky12

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Your mileage numbers seem high to start
The aggressive tread is where you lose most of your mileage
 
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ramguy11

ramguy11

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Your mileage numbers seem high to start
The aggressive tread is where you lose most of your mileage

Those numbers were hand calc.
The evic was around .3 higher.
The pre 33" tire numbers are correct and I verified them.
I checked it locally and also 3 long trips.
2- El Paso from Baton Rouge
1- gatlinburg from Baton Rouge

The post 33" numbers haven't been verified just the evic numbers.
 
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ramguy11

ramguy11

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I also have 3.73 gears and it is 4x4
I had 265/70r17 transforce at's from the factory
 

NWRQC

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Depending on the OE tire size that came with your truck and how close to a true 33" tall tire, your tires are about 1.5" - 2.5" taller than stock so your speedo is off. Between the aggressive tread and the speedo being inaccurate your mpg number will be off.

For what it's worth I have 33x12.5x20's Federal M/T's, deleted, tuned and I get about 16mpg highway. That's hand calculated, I do it every tank of fuel and have so for the past 30K miles. My overhead has never been within 3mpg even after the speedo being corrected.
 
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ramguy11

ramguy11

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The or tire size was a 30.6" tire.
Now I have a 33.2" tire

The dealership already reflashed my truck for the new tire so that's all been corrected.

Thanks for the mileage update. I can't delete the 2013 yet though.

Most Likely will be ordering the edge JWA soon for it
 

Cummins Powered

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The best I've seen, hand calculated was just over right at 24 miles per gallon. That was on a hunting trip from Flagstaff, Arizona headed back home to Texas , with 4 full grown men inside the cab. The back of the truck was loaded with several ice chest full of beer, food and hunting equipment, along with 3 mature bucks, and 2 feral hogs packed down with ice. That was with a speed of 70 miles per hour with the cruise control on. I have the Kore HP series lift close to 3 1/2 inches of lift up front and just over 1 inch of lift in the rear, with stock 17 inch rims and 35's along with the General Grabber MT's. That is the best mileage I've ever encountered, however I do use the Power Service Diesel Kleen at every fill up, with Mobil 1 5/40 Turbo diesel oil. 35's are very hard to balance them to begin with, I just rotate them every 2 to 3,000 miles.
 

V-Rod

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I always wonder why we complain about fuel milage after modding a truck in some fashion.Hrre is a novel idea, if your worried about mileage, leave it stock you can not afford it.
 

1500ram12

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Depending on how much more weight the new wheels and tires added over stock will affect mpg. But depending on where you live they might be switching over to winter blend and you will see a loss in mpg.

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regularcab2500

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i say quit ******* thats a sexy ass ****** truck!! **** gas mileage who needs it? you could rip down a damn house at the foundation.. if you need mpgs go get a car that could fit in the bed lol

did i mention thats a sexy truck ;)

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RyeThomas

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I also have 3.73 gears and it is 4x4
I had 265/70r17 transforce at's from the factory

Hate to tell ya but unless you did a gear swap all 13/14 2500 came with 3.42, no ifs ands or buts. Its one of the reasons I DID NOT buy one. Rumor has it 15 will have the 3.42/3.73/4.10 option back.
As far as tires, you have to consider the added unsprung weight and rolling resistance. No matter what anyone says even on a heavy truck tire change makes a difference. As stated nice looking rig, another factor in your mileage could be colder temps bud. No one likes to talk about it but Cold weather and then winter fuel generally equall about a 2mpg loss, at least that's my experience over the last 12 years with a CTD.
 

shaftman_05

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I see this "bashing" frequently on this forum...

Whats wrong with the notion of wanting a bad ass lifted truck on 35+ and still pull 20+ mpg? Hell dream of 30! I'm not saying it will happen but to post things like its a truck who cares, tow rating of a prius, blah blah blah is asinine. If you like dumping money start wiping your ass with $100s.

Sorry... rant over.

Weight of the new tires, slight height change, rolling resistance of the more aggresive tire, and aero dynamics is where most is lost. Small low trucks or cars with full wind funneling under belly and low rolling resistance combined with light tires is where the big mpgs come in. The factory chooses the tire to adequately boost the mileage a little higher. Sadly everything we love to do to a truck makes the mpg tank downwards.

I have heard quite a few good things about tuning all diesels. The engine will work less to acheive the same results but thats onoy if you can keep your foot out of the new found power.
 

shaftman_05

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Hate to tell ya but unless you did a gear swap all 13/14 2500 came with 3.42, no ifs ands or buts. Its one of the reasons I DID NOT buy one. Rumor has it 15 will have the 3.42/3.73/4.10 option back.
As far as tires, you have to consider the added unsprung weight and rolling resistance. No matter what anyone says even on a heavy truck tire change makes a difference. As stated nice looking rig, another factor in your mileage could be colder temps bud. No one likes to talk about it but Cold weather and then winter fuel generally equall about a 2mpg loss, at least that's my experience over the last 12 years with a CTD.
Not sure where you get this info but its wrong. I dont even see that as an option. 3.73 or 4.10 only.

http://m.ramtrucks.com/en/mobile/mo...e=ram_2500&model=big_horn_crew_cab_4x2_64_box
 

RyeThomas

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Cummins 13/14 2500 is ONLY available in 3.42, that's it end of story. As I said 15 2500 CTD you may be able to order 3.73 or 4.10. This has been beat to death on Other forums and by many other owners. It sucks but it is what it is.
I'm not wrong, thanks for playing.
 

shaftman_05

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Cummins 13/14 2500 is ONLY available in 3.42, that's it end of story. As I said 15 2500 CTD you may be able to order 3.73 or 4.10. This has been beat to death on Other forums and by many other owners. It sucks but it is what it is.
I'm not wrong, thanks for playing.
While I was simply looking for proof it appears the public didnt get these as I thought. Sorry I was not attempting to be rude. I work for chrysler at a proving grounds and have seen "things" I forget are not outside our walls. Many apologies
 

RyeThomas

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Don't apologize bud, tell them they have lost customers due to poor decisions in 13/14. The 13 2500 is a complete debackle, let's upgrade to SCR and interior but not touch the frame till next year. WTF is that?
I went used instead of new due to this and only a 3.42 option and I know others have.
 

regularcab2500

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i didnt mean to offend anyone either..its totally reasonable to want better mpgs out of your big ass truck its just not totally realistic to expect numbers like mid 20s for mpgs in a 7500lb truck made for hauling heavy loads..i hate people on here ******* that their lifted truck gets bad mpgs..of course it does haha!!! lifts, big tires and rims are only hurting your mpgs

but many ive talked to said gearing down helps tremendously

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Cummins Powered

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With these newer trucks, especially with the 13 and 14 models. You will never get the miles per gallon like the 5.9 or the earlier 6.7's with the emissions removed. There are ways to improve miles per gallon, always use the same station, keep the maximum air pressure for tires, rougher ride but will improve mpg. Use a good diesel additive such as Power Service Diesel kleen at every fill up, lubricates fuel system, less down shifting, cleans dirty injectors and prevents injectors from sticking. It improves mileage up to 8 percent, keep the air filter clean along with the fuel filters. Use a good synthetic motor oil, I use 5/40 Mobile 1 Turbo Diesel oil. Agricultural Diesel Solutions, carries the truck edition mudule for the 13 and 14 models, and will not break the bank! It's an adjustable 4 position switch stock, 30, 60, and 90 horsepower setting. Also try keeping your driving habits under the 2,000 rpm helps a bunch. Of course bigger tires and a lift will not help the situation.
 

RyeThomas

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Actually many are reporting and showing via Fuelly the 13/14's are getting better mileage than the 07.5-12 4th gens and some 5.9's. It's one of the reasons Ram/Fiat went to the 3.42 gear set, CAD system, along with SCR/DEF. Less regen's burning fuel, terrible but mileage based gears, and pulling some drag out by using CAD. All things considered the newer trucks get better mileage than the previous 6.7s and on the Highway should destroy 5.9s even more so the ones with the 4 speed 48RE auto. My 48 and 4.10's in my 06 were awesome at everything till you got on the highway, then they sucked.

Op I have a 12 with 33.6 MT's, my DD is stop and go NoVa. I have a running city average of 14.4, a best tank of 15.5 city, and my few highway miles are upper 17's, but in my area if you get on the highway and aren't going 75-80+ your going to get run over. This is a fully stock truck with 3.73's.
Your truck being a 13 should do far better than my 12. But you have to consider your driving style, elevation, location(temps and possible winter blend). Give it some miles and see how it averages out, new tires also need a couple hundred miles to break in. Again nice looking ride!
 

Arctic-Rodz

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MPG is very important, i still cant belive some here bashing others with that concern...

As I am looking into getting a new 2500 CTD im also looking to stay in the 35" tire range. But im going to stick to All Terrains. Interested in seeing how it affects MPG and power since the only option is 3.42 gears.

What would be the ideal gear ratio for those 35" tires? The original tire on some Tradesman models ive seen have 275/70R18 tires = 33.2" height. So from there to 35" isnt a hugh increase in overall height, but i imagine its the weight and resistance from the more aggressive tire you decide to run that hurts MPG the most?
 
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