The 6.4 HD Hemi Thread

[Koredova]

3.73 or 4.10

Here is a link to a pretty good article on axle ratios.

Understanding Axle Ratios | Medium Duty Work Truck Info

 

[loveracing1988]

I am hoping it will be a little better than 11-12mpg but it is a lot of steel to move down the road.

Anybody with 3.73s who does mostly city driving seeing a big difference?

You can see my Fuelly numbers, they aren't great and my truck has never really hauled anything, is a tradesman, no ram boxes, so I have pretty much the lightest crew cab 4x4 you can get. I think I will be in the mid 13's for mileage in the summer
but right now 12 is pretty good, especially now that it is going to be single digits or lower for lows. That is when my 1500 really started sucking fuel.

I do. It's not a lot better, I see 12-13 around town. And I'm anywhere from 16-19 on the highway depending on speed and wind conditions.

I can see those highway numbers going 55 or 60 with no wind when the temps aren't too low but that is about the only time. Deer season 180 miles got me an average of around 14 going 70.

 

[Chew]

If you ordered the 4.10 great...The one thing I hate I didn't order with mine but will fix if the wife lets me go to 37s. Currently thanks to the DOD I live in NM but back at home in SD I miss the 4.10 gears in the hills.



I as well have been stocking these pages about the 6.4. Last October I traded my 2013 JK Rubicon for a 2014 Mega Cab 6.4 (Plan was 2 kids... a third was blessed to us). The Jeep was my fourth jeep (93 YJ, 97TJ, and 09 JK) but due to my family growing I needed more space. I now have 5 PAXs (peps/1dude/1wife/3kiddos) and 2 dogs. The only thing I would change about mine is the gearing. I have the 3.73 and would have rather had the 4.10. My buddy has the 4.10 gears in a CC and on the highway gets better mpg then I do. This is mostly because he stays in MDS longer than I do. With CB radios we talked over mpg on a 3 hours road trip. Between my truck being heavier (also have an A.R.E. topper now; not pictured) and his 4.10 gears he got about 1.6 mpg better than I did on the same 200 (ish) mile trip (400)both ways.



When we drive from home to work (1.2 mile trip) we get about the same depending on idle time.



By the way; Thanks to everyone for the information and if anyone was wondering, my 5 year old son picked the user name. ( I realized what it was a few weeks ago). For now I have a few old pictures until the weather is better.





Attacked are a few pictures of the truck, one of the jeep, and one of my D-Max. In the jeep picture is my family trailer I steal from my parents from time to time (Cougar Fifth Wheel). The Ram 6.4 in the Black Hills of South Dakota will tow it almost as well as the 09 D-Max of my Step Dad (Ram's interior is 100X's better)!!! I also towed it with my old 2011 D-Max. (The D-Max dragged the trailer over the hills at whichever speed I wanted (85-100mph) ... same as a Cummins.., but I only tow it when on leave.) A conservative person will not care which engine is working. If drag racing with a load is your style the Cummins or D-Max will get it done. I actually prefer the slower speed of 55 going through the hills with the fam. (Besides the Ram is way sexier than the D-Max or P-Stroker and when I when I pump gas into it and people freak out priceless~



Hoping to remove some chrome soon. If anyone is interested in the door strips let me know. I'll charge shipping only... once I remove them when it isn't snowing.



P.S. This is my first post but I check this forum twice daily!

Nice post. I'm hoping to go from a '09 rubicon to a megacab 6.4. Good info on the gas mileage

 

[Big Payment]

Are their any tsb out for the 6.4 with aisin trans? Mine down shifts very hard between 28-32 mph. A simple program change would fix this.

 

[Ratket]

I didn't think you could get the 6.4 with the aisin tranny

 

[loveracing1988]

I didn't think you could get the 6.4 with the aisin tranny

You can in the 4500's I believe.

 

[regularcab2500]

Chassis cab models can get the aisin...which is the model of 6.4 with downrated horsepower lol

 

[Big Payment]

Mines a 3500 dump with 430 gear. I think its shifting from 4th to 3rd when it does it.
It really needs to slow down to about 25mph before the down shift. Its only noticeable empty also. When loaded or towing its perfect. I haven't drivin one with the dodge trans but this aisin has 0 torgue management. Torgue converter is always under full pressure. When you let of the gas the trans drags the speed right down and down shifts. Feels like it has a engine brake great for towing. Down rated horsepower?? 367hp@4000 rpm vs 410hp@ 5600 rpm. Do you work for the Obama administration?
Trust me its the same engine without the mds

 

[6.4 dude]

New tires and wheels ordered, exhausting but anxious!

 

[w6pea]

Ford 7.5L "460" Cid Vs Dodge 6.4 Hemi

Right now I am driving a Ford F-250 XLT 1995.(I can not see putting more money in a 20yr. old vehicle) I am going to buy a new truck. I like the V-8 Gas. I also Like the Cummins Diesel.

I have over 200,000 miles on my Ford. It's starting to nickel and dime me to death. In the past three months I could have made payments on a new Dodge Ram 3500 as compared to what I paid for new brakes and other repairs. I like the Hemi and am glad to see they brought it back and it's available.

Can some of you folks give me some pro's and cons between the Cummins and the Hemi.

 

[NewBlackDak]

If you haven't decided, get the 4.10s. I have one of the better mileage 6.4s, and I have 4.10s


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[kohldad]

I have the 3.73 and would have rather had the 4.10. My buddy has the 4.10 gears in a CC and on the highway gets better mpg then I do. This is mostly because he stays in MDS longer than I do.

I almost went with 4.10s for this very reason but decided the 3.73 would work better when in tow haul mode. Only have 36 miles on it after 3 days of ownership, but so far I've been impressed where I can keep the MDS active. But I can already tell, to get anything decent is going to take a lot of care.

 

[TWILLIAMS9]

Right now I am driving a Ford F-250 XLT 1995.(I can not see putting more money in a 20yr. old vehicle) I am going to buy a new truck. I like the V-8 Gas. I also Like the Cummins Diesel.

I have over 200,000 miles on my Ford. It's starting to nickel and dime me to death. In the past three months I could have made payments on a new Dodge Ram 3500 as compared to what I paid for new brakes and other repairs. I like the Hemi and am glad to see they brought it back and it's available.

Can some of you folks give me some pro's and cons between the Cummins and the Hemi.

Pros on the 6.4 over the 6.7: cheaper, no new epa emission crap, designed to be more of a truck type gas engine, made to be low cost maintenance and reliable, doesn't mind short stop and go trips. Honestly if you don't tow heavy often get the 6.4 and save yourself some money. I wanted a diesel when I was shopping, decided I couldn't justify the price tag since I have absolutely zero need for a diesel and I actually preferred the way the 6.4 felt on my test drives.

 

[RAMYOU]

Pros on the 6.4 over the 6.7: cheaper, no new epa emission crap, designed to be more of a truck type gas engine, made to be low cost maintenance and reliable, doesn't mind short stop and go trips. Honestly if you don't tow heavy often get the 6.4 and save yourself some money. I wanted a diesel when I was shopping, decided I couldn't justify the price tag since I have absolutely zero need for a diesel and I actually preferred the way the 6.4 felt on my test drives.

Have you done any exhaust work on your truck yet?

 

[TWILLIAMS9]

I have not yet but I'm going with the mufflex replacement muffler here at the end of the month.


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[RAMYOU]

I have not yet but I'm going with the mufflex replacement muffler here at the end of the month.


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Mufflex DOD250035? I was actually lookin at this too. On their website it says the kit has Magnaflow muffler built in it, but doesnt say what size or which Magnaflow muffler. Looks pretty small from the picture but the video they have sounds just a little bit louder than stock

 

[TWILLIAMS9]

Yeah I wanted to hear it when I open it up, but while I'm cruising I like the quiet cabin. It also has one of the best flow through designs so you can get an extra mpg which I really need now lol


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[Ratket]

I'm getting steps/flex-undercover/and exhaust done next weekend, worst case scenario " if the shop doesn't have a muffler I want or wants to much money" I will have them do the muffler back and I will do the mufflex when I get home. I am also hoping to find a dyno and get a few pulls in to see where the truck sits on putting power to the ground.

 

[loveracing1988]

Mufflex DOD250035? I was actually lookin at this too. On their website it says the kit has Magnaflow muffler built in it, but doesnt say what size or which Magnaflow muffler. Looks pretty small from the picture but the video they have sounds just a little bit louder than stock

It is one of the race style mufflers, so I doubt it would be on the quiet side.

 

[w6pea]

Pros on the 6.4 over the 6.7: cheaper, no new epa emission crap, designed to be more of a truck type gas engine, made to be low cost maintenance and reliable, doesn't mind short stop and go trips. Honestly if you don't tow heavy often get the 6.4 and save yourself some money. I wanted a diesel when I was shopping, decided I couldn't justify the price tag since I have absolutely zero need for a diesel and I actually preferred the way the 6.4 felt on my test drives.

With my F-250 it has a 7.5 L "460" cid.Motor. Compared to that motor as for pulling power how is the Hemi compare? What rear ends do you have ? My current has a 4:10.1 Positrac. 1ton Rear End. If I set the cruise ontrol I can get about 11 to 13 mpg.