People who have 28 inch tires on the dodge Dakota rt run 4.56 gears , I would go 4.56

 

He did already.... with 28" tires and those gears mpg is not even a considered factor anymore... power is great fuel ecomomy would be worse than usual unless it sees a lot of hills every day... then it might not do too bad...

 

Well she's back... WTF, why didn't I regear eleven years ago! The 4.56 and 285's are awsome! I ran 40 miles of highway at 70 GPS MPH and got 16.2 MPG; The best I ever got before was 14.5. I ran with the cruise on and pulled plenty of hills and the transmission never dropped out of over drive. I don't see any around-town differences other than the RPM's are the same or lower as O/D licks in sooner than before. I''m gonna put some miles on her and then change the gear oil before towing so I'll report back. 70 GPS MPH ran 2,200 RMP, my 3.55's ran 1,700. I'm F-bomb impressed. Glad I didn't go 4.10.

 

Gears make a much bigger difference than people want to believe because of the costs involved in changing them.... most feel if they just ignore them they wont be a factor.... or they really dont realize how they work with tire size to effect things...

 

Nice man . I have trouble hitting the checkout button . I most Lilly would but I'm not really into haveing a single cab anymore . Being my gf has 2 kids ext .

Think imma wait and get my hemi quad cab and do 4.56 as my first mod

 

funny, your perspective..

just yesterday i was driving the truck on an open road with a posted 45mph speed limit, and popped off the o/d.. @ 50~55ish MPH, the tach jumped several hundred RPM, but the vacuum gauge picked up well over 5 inches.. the stress on the engine was way WAY down, which equates to better mileage RPM's be damned..

understand this, though (and this is pretty much my opinion only) 4.56:1 gears are just a band-aid.. they are a dang good one though.. the real issue with these trucks @ highway speeds w/ o/d engaged is their weight, and the huge drop in leverage (ratio difference between 3rd 1:1 and w/ o/d engaged)... our trucks would get a LOT better gas mileage with a lower (higher numerically) ratio o/d than they do with that huge step from 3rd 1:1 and fourth locked.. on paper, they get better mileage with the higher (lower numerically) o/d ratio- which allows mother Mopar to advertise better than reality mileage, and keeps the EPA and congressionally mandated mileage standards in check..

it's basically theory vs. reality.. the theory of a high ratio o/d is better mileage, the reality is quite the opposite.

 

Gotta agree with ya there drew. Keeping the engine where it is actually making more than enough power to throw the 5000+ pound brick down the road will net you better economy than having the engine struggling at lower RPM.

I think there are .75 ratio O/D's available...... I think.... but, I don't know anyone that's tried one.

 

if you're right about those o/d's- when my transmission finally gives up the ghost and I nail a PATC to the back of the engine, dangling off that will be what you speak of..

that and/or... and, yes- I'm serious: mr. 727 here I come..

 

As far I can tell You guys are saying the same thing as the op? and we are all in agreement.... 4.56 gears will raise the rpm's in all cruising speeds and actually lower the actual final od ratio? this keeps the truck in a higher powerband and puts less lag on the engine and transmission..... 33" tires and gears like 3.55 would put be hypothetically like an extra high overdrive.... its just like shifting all your gear ratios up or down depending on which way you go... if the wind and other conditions were all just right it may net better mpg but if conditions are otherwise....it will suffer.

I think it related well to the ten speed bike analogy.... you pedal slower in higher gears but it takes more energy and puts a higher load / strain on your muscles ... this also makes you downshift more on the slightest incline but if you at the magic speed in optimal conditions you achieve the best results in high gear...
but unlike the human muscle an engine and transmission doesnt get stronger from any of this...it just wears out quicker...

 

That's essentially it.