MPG Drop w/ 3.21s on 35's

sbuko213 · Feb 25, 2015

So I'm really back and forth on getting 33s or 35s. I have the 3.21s and really can't justify the money for the regear. Just looking to see what the mpg/power drop is when upping to 35s on the 3.21s. I do have a diablosport already on there so that may help a little. Any input will be appreciated.

Copperhead7310 · Feb 25, 2015

The engine and camshaft design (power range, where the engine is the most efficient) changes when you go to a larger diameter tire and wheel combo. The 33" tire for example. If you had the tire off and marked a small chalk line at the bottom. Roll it one full rotation. It would cover .. 'X' amount of distance. (Circumference= 103.68) Go up to 35" and it's 109.95. The 35" tire covers more distance per one revolution.

This will drop your 3.21 ratio down a bit. So, it would be almost the equivalent of one gear change maybe (?) and in my opinion would make the truck kinda sluggish around town.

Think about the weight if the tire too, that also impacts the mpg. plus the fact the cam is out of it's power range and the engine is having to work harder to make the same power. The 275/60 is 32.99" tall, me I think I'd go with the 33's. IF you change to 3.92's then yes, it would handle 35's no problem.

Just thinking out loud.

dodge dude94 · Feb 25, 2015

Even with a Hemi, 3.21s on 35s will be a complete dog and will drop MPG all over simply because the transmission will be having to kick down all the time. Especially if you have any hills at all where you live.

brandonjansen · Feb 25, 2015

To answer your question, you're going to lose roughly 1.5-2 mpg going to a 35" tire. That's typical regardless of what gear ratio the truck has. As others have stated though, the issue you'll notice more is how slug-ish the truck will feel to get moving from a standstill. Overall it just won't have as much "get up and go" as it does with the smaller tires.

Jerry1984 · Feb 25, 2015

Stock 275/60/20 tires are right at 33 inches. If I get custom wheels I would go with a slightly more aggressive than stock offset at +10 on a 17x9 inch wide wheel with 295/70/17 tire which is nearly identical to stock overall diameter while giving more sidewall and a slightly more aggressive stance.

xrsman · Feb 25, 2015

When my truck was stock I could get around 10-10.5 L/100 kms (24 mpg).

When I did the lift it dropped to 11.5-12 L/100 kms. (21 mpg)

When I installed my 35's it dropped to between 13-13.5 L/100 kms. (17-18 mpg)

I have a 2014 1500 longhorn CC 3.92 gears 4x4. Performance Mods are a hemifever tune always on 91 octane, S&B cai, MBRP cat back.

Those mods increased my mileage, i've had them on for all of the above mpg numbers. My mileage would be worse without them. All in all I'm happy though, I knew what I was getting Into and I love the way it looks!

Copperhead7310 · Feb 25, 2015

I posted 31.99 for the 275/60 above, my bad. It is 32.99 in tall. 275/25.4*.60*2+20

For some reason I was thinking 31.99 from memory but .. oh well.

Still brother man, I dont think I'd do 35s on the 3.21 gears.

Burla · Feb 25, 2015

Wrong gear for 35's, go with 33's unless there is a reason like wheeling or trail riding.

You can make 33's kind of look like 35's by getting a smaller rim like a 17 or even 16, Top pic is 35's on 20 inch rims, second pic 33's on 16 inch rims. IMO 17 inch rims with 33's is the sweet spot, that is the 3rd pic, 33 with 17's. Never mind the rims, just look at it for sizing. Added a 4th pic, 17 inch rims on 33's, nicer rims. Final pic is 33's on 20's, there just is not a lot of meat on the tire like all of the other options.

Are you getting AT's or MT's?

used-2012-jeep-wrangler_4x4-unlimited4inchlift35inchtires20inchblackrims-8417-9595281-32-640.jpg

used-2007-jeep-wrangler_4x4-3inchlift33inchtiresprocomprims-8417-10624153-17-640.jpg

used-2009-jeep-wrangler_4x4-unlimited3inchlift33inchtiresxdrims-8417-9449562-22-640.jpg

brandonjansen · Feb 26, 2015

Burla said:
Wrong gear for 35's, go with 33's unless there is a reason like wheeling or trail riding.

You can make 33's kind of look like 35's by getting a smaller rim like a 17 or even 16, Top pic is 35's on 20 inch rims, second pic 33's on 16 inch rims. IMO 17 inch rims with 33's is the sweet spot, that is the 3rd pic, 33 with 17's. Never mind the rims, just look at it for sizing. Added a 4th pic, 17 inch rims on 33's, nicer rims. Final pic is 33's on 20's, there just is not a lot of meat on the tire like all of the other options.

Are you getting AT's or MT's?

FYI you can't run smaller than a 17" rim on a 3rd or 4th gen Ram. They won't clear the brake calipers.

averageguy · Feb 26, 2015

Another advantage to a smaller rim and more side wall is when you have to let air out for off roading in sand. The short tires don't grip well at all. Also, a taller side wall means if your spinning in mud your rim is a little farther away from getting scratched and gouged from the sides of the rut your digging.

sbuko213 · Feb 26, 2015

Well I'll be getting 17" with a -12 offset wheels. The tires I'm looking at are the Red Letter Grabbers (I like the look). Since I'm doing a coilover level (to gain travel) and don't want to put on the big fenders either, it's starting to look like the 33s will be the best option with this in addition to the above mentioned reasons. Especially since this is daily.

I do like the get up and go I have now, and all I have is a DS 87 Can tune on it right now. S&B is sitting in the box still, and flowmaster catback will be ordered when the funds are available. Sounds like I'll be getting the 33s.

sbuko213 · Feb 26, 2015

Burla said:
Wrong gear for 35's, go with 33's unless there is a reason like wheeling or trail riding.

You can make 33's kind of look like 35's by getting a smaller rim like a 17 or even 16, Top pic is 35's on 20 inch rims, second pic 33's on 16 inch rims. IMO 17 inch rims with 33's is the sweet spot, that is the 3rd pic, 33 with 17's. Never mind the rims, just look at it for sizing. Added a 4th pic, 17 inch rims on 33's, nicer rims. Final pic is 33's on 20's, there just is not a lot of meat on the tire like all of the other options.

Are you getting AT's or MT's?

Getting Red Letter Grabbers in specific. Already decided on 17" rim w/ -12 offset a while back. Just trying to figure out tire size, and it looks like 33 is the way to go.

Sausage · Feb 26, 2015

Well I have 6in lift pro comp with 35x12.5x20 on a 2014 ram 1500 4x4 cc sport with 3:21 gears and they do the job, but like what was said in hills it will up shift alot. But it will turn the 35's over without a problem. As far as MPG. I am averaging 16 to 16.5 and that is city/hwy. Before the lift and tires 18.5 avg. At 60mph now I get 16, before factory I was getting 21. I live in flat country and the speed is 55mph so I drive around 52mph mainly and I can get avg of 18 at that speed. So that is where I try to stay. Should of gotten the Eco, but no turning back now.

HemiPower36 · Feb 27, 2015

IMO, if you cannot afford the 3.92 regear, then you should not put 35's on. Again, my opinion, to clear the 35" tires you need a suspension lift. Those can get pricey. Next, sweet rims to complete the look. Including the price of labor, you are hovering around 5k. If you are willing to drop that kind of loot, then get a regear.

For you, I recommend a leveling shock. Not those awful leveling spacers. Then get 33" tires with some cool rims.

loveracing1988 · Feb 27, 2015

sbuko213 said:
Well I'll be getting 17" with a -12 offset wheels. The tires I'm looking at are the Red Letter Grabbers (I like the look). Since I'm doing a coilover level (to gain travel) and don't want to put on the big fenders either, it's starting to look like the 33s will be the best option with this in addition to the above mentioned reasons. Especially since this is daily.

I do like the get up and go I have now, and all I have is a DS 87 Can tune on it right now. S&B is sitting in the box still, and flowmaster catback will be ordered when the funds are available. Sounds like I'll be getting the 33s.

From every review I have read those red letter tires are horrendous in any cold weather, so any snow or ice your truck will be next to impossible to drive.

sbuko213 · Feb 27, 2015

HemiPower36 said:
IMO, if you cannot afford the 3.92 regear, then you should not put 35's on. Again, my opinion, to clear the 35" tires you need a suspension lift. Those can get pricey. Next, sweet rims to complete the look. Including the price of labor, you are hovering around 5k. If you are willing to drop that kind of loot, then get a regear.

For you, I recommend a leveling shock. Not those awful leveling spacers. Then get 33" tires with some cool rims.

I already have that planned out. I'm basically doing a Stage 1 RamRunner suspension with the King OEM replacements (the coilover up front gives me up to 2.5" of lift) and I'll be getting Total Chaos UCAs to help add some more travel up front. May go 1.5" in the back with the Icon Springs but not sure yet. Decided to spent the money on the suspension haha

sbuko213 · Feb 27, 2015

loveracing1988 said:
From every review I have read those red letter tires are horrendous in any cold weather, so any snow or ice your truck will be next to impossible to drive.

Well I'm leaving for Active Duty in May and I'm getting stationed in eastern New Mexico, and the winters are nowhere near as bad as what I've been living with in New Jersey my whole life.

I've actually seen a few guys with them up here in NJ. So they either don't know or aren't having any issues haha. If I was going to be staying up here I'd look at something different, but I'm moving to the southwest in a few months so I'm not as worried about that.

Copperhead7310 · Feb 27, 2015

Regardless of tires, gears, mpg, etc. I just wanted to say thank you for your service to our country. Very much appreciated.

Chad

kg93 · Feb 27, 2015

sbuko213 said:
Well I'm leaving for Active Duty in May and I'm getting stationed in eastern New Mexico, and the winters are nowhere near as bad as what I've been living with in New Jersey my whole life.

I've actually seen a few guys with them up here in NJ. So they either don't know or aren't having any issues haha. If I was going to be staying up here I'd look at something different, but I'm moving to the southwest in a few months so I'm not as worried about that.

i have a few raptor guys that frequently come to my job. They run grabbers for the most part, i havent heard any complaints from them

loveracing1988 · Feb 27, 2015

sbuko213 said:
Well I'm leaving for Active Duty in May and I'm getting stationed in eastern New Mexico, and the winters are nowhere near as bad as what I've been living with in New Jersey my whole life.

I've actually seen a few guys with them up here in NJ. So they either don't know or aren't having any issues haha. If I was going to be staying up here I'd look at something different, but I'm moving to the southwest in a few months so I'm not as worried about that.

That makes sense, they were developed for desert racing.

MPG Drop w/ 3.21s on 35's

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