2500 6.4 35 or 37 inch ire MPG

[Noblezero13]

Hello all.

Im debating on putting on 35 or 37 inch tires on my '17 Ram 2500 6.4

I looking to know what MPG you guys with a lift and these size tires are getting with a corrected speedo.

Thanks for any help I can get.

 

[6.4LMegaMan]

I've had my 2" level and 35s on for about 15k miles and am averaging about 11.5 to 12mpg during my daily stop and go hilly driving. It's really about as bad driving conditions as you can get so I don't think it could go any less. I use the AEV ProCal to adjust for the tire size and hand calculate. On the highway I can get 15 if I baby it. I have 3.73 gears on a 2016 Mega cab with the 6.4. I'm contemplating going to 37s next time but am thinking I should install 4.88s first.

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[[email protected]]

I have a 2016 2500 CC with the 6.4. 5.5 inch BDS lift with 20in fuel rims and 37 in tires. I had 3.73 gears was getting around 9 or 10 MPG everyday driving. I just went to 4.56 gears and it is much better in the city. Only like 500 miles on the new gears so no update on MPG. But its around 11 12 right now.

Tires I'm running are the Nitto Ridge Grapplers 37x12.50 20 LT.

 

[Nick@GotExhaust]

I have a 2016 2500 CC with the 6.4. 5.5 inch BDS lift with 20in fuel rims and 37 in tires. I had 3.73 gears was getting around 9 or 10 MPG everyday driving. I just went to 4.56 gears and it is much better in the city. Only like 500 miles on the new gears so no update on MPG. But its around 11 12 right now.View attachment 121944 View attachment 121945

Tires I'm running are the Nitto Ridge Grapplers 37x12.50 20 LT.

Looks great!

 

[[email protected]]

Looks great!

Thanks Nick

 

[Gear Jammer]

With stock tires and 4:10's I was averaging around 13-13.5, I'm not nice to the skinny pedal, with the 35's and the Thuren springs the computer says 12.5 I haven't hand calculated it yet. I corrected the speedo for tire size and verified it with GPS and the mile posts on the side of the highway.

Update: Hand calculated it's 11.5-12 MPG

 

[OzarksRam]

From looking at everyone's comments, what's shocking to me is that tire size doesn't seem to make as big of an impact as I thought. Especially if you re-gear. I do a lot of in-town driving and my average is 10-11 mpg. I even saw single digits when it was below 0 and I had a lot of idle time. I did see a drop in my highway MPG when I went to a wider mud tire (325/60R18) but I assumed going to a 35" or 37" tire would just destroy your mileage but it doesn't seem be that way.

 

[6.4LMegaMan]

From looking at everyone's comments, what's shocking to me is that tire size doesn't seem to make as big of an impact as I thought. Especially if you re-gear. I do a lot of in-town driving and my average is 10-11 mpg. I even saw single digits when it was below 0 and I had a lot of idle time. I did see a drop in my highway MPG when I went to a wider mud tire (325/60R18) but I assumed going to a 35" or 37" tire would just destroy your mileage but it doesn't seem be that way.

Let me clarify I am using Toyo Open Country AT2 extreme 295/65R20 which measure to exactly 35" installed. Maybe being a tad skinnier is helping me? Also when the temp drops below freezing and I use remote start to warm up my average drops to 10.5 - 11.5. I'm curious to see if my average improves at all when the temps warm up come summer time.

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[14RAM4X4]

2015 CC 4x4 short bed. Running 37x12.50r20s on a 3"/1" lift. I average about 10 - 11 mpg lately. I can get up to 12-13 city if I baby it and about 14 hwy if I keep it about 65 mpg. I'd been averaging 12 - 13 daily driving, but lately, I've been in a hurry, so my mpg dropped off quite a bit. Hand calc, I'm about 10.4.

I used the ProCal to correct OD for tire size. When I save up, I'll probably go 4.56 gears.

 

[Fearfact]

I’m on 285/75r18 (35x11.5ish) Cooper discoverer AT3 in stock suspension. I haven’t noticed any real drop in mpg or power whether it’s empty or with 15k behind. Eventually I’ll probably get a set of thuren front springs just to smooth the ride a bit


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[Dmopar74]

I’m on 285/75r18 (35x11.5ish) Cooper discoverer AT3 in stock suspension. I haven’t noticed any real drop in mpg or power whether it’s empty or with 15k behind. Eventually I’ll probably get a set of thuren front springs just to smooth the ride a bit


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Do you have a picture, been thinking of the same size at3

 

[mohemipar]

Just to add after the fact, if you are doing any kind of lift even just a level, get 37's. Gotta go with a 37 on these big trucks if you are lifting them at all.

IMO 35's look just right on a stock suspension HD.

Mine has had 35's and with 4.10s I barely noticed a loss of performance - if at all. MPG actually seemed pretty unaffected surprisingly.

 

[pwjouster]

transmission still sucks!

3K miles on 35s and i wish i got 37s... lol

 

[mohemipar]

transmission still sucks!

3K miles on 35s and i wish i got 37s... lol

For PW, yep lol. They come a 1.5 - 2 inches taller up front than the regular 2500.

 

[pwjouster]

For PW, yep lol. They come a 1.5 - 2 inches taller up front than the regular 2500.

well i knew i wanted to start out with 35s due to the fact im still a month or so away from my shocks and lift install.

im rubbing with 35s and method nv 17s. not a good setup if you offroad. you need to either lift, or trim the rear of the front wheel wells.

37s will require a good amount of chop to clear without lift.

 

[mohemipar]

well i knew i wanted to start out with 35s due to the fact im still a month or so away from my shocks and lift install.

im rubbing with 35s and method nv 17s. not a good setup if you offroad. you need to either lift, or trim the rear of the front wheel wells.

37s will require a good amount of chop to clear without lift.

That is true. I guess I was thinking of with an aftermarket wheel with the right offset. I have AEV's on my regular 2500 and no rub.

 

[Fearfact]

Do you have a picture, been thinking of the same size at3

Sorry for the delay getting back to you

 

[MasonD21]

Just got my 35's on my truck last week. I do a lot of city driving. So I went from 9mpg average to 7.

Trip 400 miles to the coast and back I pulled 18.

I havent calibrated my speedo yet, so the transmission isn't really dialed in that well and the Lie-O-Meter is inaccurate.

Loud pedal is still happily loud, fuel gauge moves when floored, stops moving when I drive it like a grandpa. That's all I care about.

 

[Alexpaul09]

I have a '14 6.4 and had 2.5" level and 35x12.5 bfg mud terrains on and best I could get is 13.5. I put it back to stock and put my Firestone transforce HT tires on 275/70r18 and I average 14.5 now. 18 on the high way

 

[Fearfact]

If you went with a less aggressive tire you wouldn’t see much of a difference... and you’d be done with those horrible firestones


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