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I've read the threads about gearing ratios and the more I read the more I wonder what to get. I'm looking for the max benefit from the ecodiesel, mainly my latest decision to go with a diesel truck this time around. The confusion is in wheel size paired with gear ratio and what type of economy comes from it. The truck will mostly be used on highway/turnpike driving in sunny south flat ass Florida with minimal around town driving, lets say 80/20, not really ever towing anything or heavy loads. Someone who is more savvy with this could possibly explain the differences with 17 vs 20 wheels paired with gear options. All of this is obviously dependent on the right foot's cooperation but consciously thinking about fuel savings and using cruise control as much as possible should help. Thanks for an explanation even if this horse has been beaten way too many times.
 

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If all you care about is maximum highway fuel economy than get 20" wheels with 3.55 gearing. However that being said, I did the math and posted it in a thread that showed over 150,000 miles with diesel at $4/gal the difference between 28mpg and 26mpg was like $1,600 over that 150k miles. So not much savings for so much effort to maximize the economy.

If you want to maximize the economy you'd want a chip or tune for the truck or even and intake/exhaust upgrade. most tunes cost between $300-$700 but increase is usually 10-30% fuel economy with diesels and a payback of around 20-50k miles.
 

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There is support for the engine overseas and for the jeep grand Cherokee so it shouldn't be too hard to transition to the ram.
 

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I don't think there is a active 'delete" available for the 2013-2014 2500 Cummins yet. There are lots of computer issues in addition to the removal or deactivation of the exhaust-stroke fuel injection/regeneration and the Diesel Injection equipment.

Also read there are increasing government enforcement on suppliers of kits to "delete" the emissions.

Not sure I'm absolutely correct but that's the gist of what I have been reading. That issue tells me a "delete" on the 3.0, though rumored in Europe, is not easily forecoming.
 

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If we're all patient, somebody like Diablosport always figures out some tuning products eventually. As far as deleting equipment goes, you probably want to wait until your warranty is done(I expect to out-drive mine by year 4-5) because I'm one of the biggest backers of this engine but I can't see it being cheap to rebuild. Tuning chips, intakes, and exhausts are the kinds of things dealer shops will ignore but large-scale mechanical modifications like that blow your warranty. I'm going to all kinds of stuff to it once warranty is up and I've found with lots of vehicles these days the performance parts actually cost less than OEM replacements so I'm not going to feel the least bit bad about it.

I'll wager by the time it's relevant the market will be flooded with both trucks and parts for us all to play with.
 

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You click that DieselPower link and the pop-ups will overwhelm you.

The 20" tires look like a rather lower profile than the normal 17" tires. That lower profile would tell me the circumference difference between the two is not all that much. How much is "not all that much"?

If there's little difference there will be little final gearing difference between the 20 and 17" tires. Doubt that issue will affect fuel mileage significantly.

Another issue is to answer a simple question. Is fuel mileage a big issue because of expense?

If expense is the issue a 20" tire may not be the answer. First issue is they are expensive compared to the 17's. Since they are low profile they are much less forgiving in the sidewall and will affect ride. They also tend to have a thinner tread and carcass design. That means it's easier to puncture and gets mostly less tire mileage. All that is expensive.

When I see large tires, illegally tinted windows and hear loud music it's probably trouble for a lot of reasons.
 

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The 20" tires look like a rather lower profile than the normal 17" tires. That lower profile would tell me the circumference difference between the two is not all that much. How much is "not all that much"?

If there's little difference there will be little final gearing difference between the 20 and 17" tires. Doubt that issue will affect fuel mileage significantly.

Another issue is to answer a simple question. Is fuel mileage a big issue because of expense?

If expense is the issue a 20" tire may not be the answer. First issue is they are expensive compared to the 17's. Since they are low profile they are much less forgiving in the sidewall and will affect ride. They also tend to have a thinner tread and carcass design. That means it's easier to puncture and gets mostly less tire mileage. All that is expensive.
Tires certainly affect fuel economy because of their friction and weight. Many tradeoffs in our choices, just depends on priorities. The 17" is slightly smaller than the 20" with revs per mile about 4% greater which I doubt affects fuel economy. The practical advantage of 20" tires is road handling because of the wider footprint and stiffer sidewalls. The 17" is better in most other respects. If it's for looks, whatever.

Stock tires are Wrangler SR-A all-season street tires:
P265/70R17, 31.7" dia, 10.7" width, 660 rpm, 37 lbs, 2535 load, 44 psi, $139 (TireRack)
P275/60R20, 33.0" dia, 11.0" width, 634 rpm, 40 lbs, 2601 load, 44 psi, $125 (TireRack special)

These tires rank 34 out of 41 in the category on TireRack's user survey with no superior qualities and a low rating for ice traction.
There are 113 choices at TireRack in P265/70R17 versus 29 choices in P275/60R20.
The 17" wheel-tire combination weighs 8.3 lbs less than the 20" (x5 for 4 tires and the spare).

Some of us will want LT tires which add weight, cost and rough ride. From my research a good LT tire is the Wrangler All-Terrain Adventure with Kevlar Pro-Grade, premium on-/off-road all-terrain, E-rated, severe winter rated:
LT265/70R17, 31.7" dia, 10.7" width, 660 rpm, 50 lbs, 3195 load, 80 psi, $214
LT275/65R20, 34.1" dia, 11.0" width, 610 rpm, 56 lbs, 3750 load, 80 psi, $320

That's right, 13 lbs more per tire for 17" but puncture-resistance, load rating and traction are worth it. The Adventure is a new tire that replaces the SilentArmor which were ranked 4 out of 19 in the category on TireRack's user survey with all excellent or superior qualities and within 98% of the category leader (Firestone Destination A/T, $205 for 17"). The Adventure is the only tire in the top 4 that is severe winter rated which matters to me.
 
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Bigfoot. I have had 2 sets of Bridgestone Dueler A/T Revo 2 (On-/Off-Road All-Terrain) tires over the last 10 years. I really like them on snow, mud, ice and dry pavement. You get some road noise, but it is not that bad. Just more than the stock tires. Which should be obvious.

You can also get a LT version of the tire.

I am constantly going from pasture to road and I have yet to lose traction with those tires. I will put them on my new truck.
 

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Like always, good info from Bigfoot
 

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With 212,000 miles on my current Cummins 2500 I am on my 2nd replacement (third set) of Michelin tires. Using the spare once, I have only ever bought 7 tires since the truck was new.

Have no clue why the new trucks no longer use Michelin. My guess would be expense. Far as I'm concerned most all other brands wear out fast and are not worth the hassle buying.

That information presented is good. Tire prices initially are on a sale and non-sale comparison so may not be real valid. I have never bought and will not be getting giant tires so I can pay a lot of money to show-off my fancy spinner/chrome rims.

As for handling I assume the 20" tires are a lot wider. Per a given weight I would think that the less pressure per area on the wider tire would make it more prone to hydroplaning. Also, you do have more area to hit stuff with. Then there's the issue of debris thrown onto the sides of the truck. I see oh so many that do not immediately install mudflaps. Then a look at their truck and the paint is damaged from debris thrown right against the side of the truck.

Oh so often I just cannot figure things out.
 

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Bigfoot. I have had 2 sets of Bridgestone Dueler A/T Revo 2 (On-/Off-Road All-Terrain) tires over the last 10 years. I really like them on snow, mud, ice and dry pavement. You get some road noise, but it is not that bad. Just more than the stock tires. Which should be obvious.

You can also get a LT version of the tire.

I am constantly going from pasture to road and I have yet to lose traction with those tires. I will put them on my new truck.
That looks like a good tire with an interesting tread pattern. I've had some Bridgestone car tires in the past and they worked well. So many choices!

Unfortunately they are not severe winter rated (snowflake on mountain symbol) which I want. Most people may not care about the winter rating but I often travel in the snow zone, and in Oregon these tires can legally be used instead of chains or studs in chain-control areas. I carry chains, too, but rarely need them. I used to have separate summer and winter tires but tire technology constantly improves and there are now winter tires that can be used all year with good tread life. I have all-year winter Nokian tires on our car and they work very well but are hard to find for sale. I was happy to come across the Goodyear Adventure Pro-Grade LT tires which get good reviews and seem a great match for the Ram.
 

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My vote would be for 17s. Many more choices in tire sizes, brand and tread patters. I’m not a fan of 20s like this for a “truck”, unless you are just driving it to the mall or soccer practice.

“According to Chrysler, the Ram brand will concentrate on "real truck customers," rather than casual truck buyers who buy trucks for image or style” (Ram Trucks - Wikipedia, the free encyclopedia)

OK, then what is up with these 20s?
 

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My vote would be for 17s. Many more choices in tire sizes, brand and tread patters. I’m not a fan of 20s like this for a “truck”, unless you are just driving it to the mall or soccer practice.

“According to Chrysler, the Ram brand will concentrate on "real truck customers," rather than casual truck buyers who buy trucks for image or style” (Ram Trucks - Wikipedia, the free encyclopedia)

OK, then what is up with these 20s?
Truck customers like big wheels.

Truck customers like being referred to as "real truck customers."

Marketing Dept's produce happy noises, not precise and accurate communication.
 

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Truck customers like big wheels.

Truck customers like being referred to as "real truck customers."

Marketing Dept's produce happy noises, not precise and accurate communication.
Where I live, its easier to find tires for 20's if you bust one near the end of winter. 17s are one of THE most common truck rims so the tires are more popular.
 
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