5.7L Vs. 6.4L 2500

[Caldwell]

Hey Fella's,

the more I follow the ( 6.4L Thread ) the more im really interested in looking into a 3/4 ton. Now I cant say that I really need one, however I can say that I am interested in possibly plowing this coming winter. Secondly Im use to bad gas mileage anyway, so gas isnt really a concern for me. I like the idea that I have a truck capable of just about anything I could throw at it. Not having to lift it is awesome also lol. Now onto the point of the question.

Has anyone test driven a 5.7L 2500 w/ 4.10's compared to a 6.4L w/ 4.10's ?

is there that much of a noticeable difference between the to engines ?

there are some pretty well priced tradesmen / slt models with varying 5.7's and 6.4's in my immediate area.

 

[ammo]

Yes there is. I recommend you go test drive them both and you will see for yourself.

 

[Lhemi]

What he said ^^^^!!!

 

[TWILLIAMS9]

You have to remember that the 6.4 is detuned and made to last longer than a 5.7 especially when doing truck type work. I guarantee that you will be able to make incredible power if you want to with the 6.4 seeing as the srt's 6.4 are 470/470 hp/tq and the trucks are 410/429.

 

[WhiteExpress]

I have a '13 5.7 4x4 Crew Cab with 3.73s
Dad has a '14 6.4 4x4 Crew Cab with 3.73s

Mind you, he has the all new suspension etc, but other than his being fancy (BigHorn) and mine (Tradesman) not, mechanically, there good enough to compare, same trans etc.

I like the way his 6.4 drives over my 5.7. I think tuned (No MDS) it'd be near perfect.
That being said, there are a few things about it I don't care for:
- They moved a bunch of stuff around under the hood, and some of it just seems stupid.
- I also don't care for the 'closed' coolant system (pressure cap on reservoir).
- Also VERY glad to be free (entirely, not just turned off) of that MDS crap. I hate it!
- The exhaust is like 4" into the HUGE muffler, and has a giant resonator that hangs waaay down low

Again, back to just driving impression, daaang, that 6.4 gets it.
He also has the BigHorn 18"/33" wheel/tire combo, I have the 17/30" so mine should be 'quicker' and boy it's NOT.

 

[Caldwell]

WHITEEXPRESS,

thanks for your comparison of the two. I do appreciate it.

i was just curious if the slight horsepower difference made that much of a difference, if both trucks side by side have the same trans / gears. clearly in your explanation this is the case. If I could make a good enough deal to get out of my lease without killing myself I would jump on it. I would just pray for atleast 10mpg in local ( Philadelphia ) stop / go traffic.

I would love to see the real world dyno numbers of each respective platform for a comparison. then I would love to see the results of a 93 octane tuned 6.4L. with that being said these vehicles are clearly not drag racers. I could only imagine what an ( intake, throttle body, shorty headers, exhaust, tune ) would do to the power curve.

 

[Donelam304]

On the exhaust, the 6.4's have 2½" pipes coming out of the cats, that is mashed flat in to a Y pipe that's 3½" in to the muffler and then 3½" in to a resonator and then 3½"out the tip. Yes the resonator hangs down and is quite ugly.

I painted mine flat black with some engine paint till I had true duals installed. I went with a Jones 40 series muffler and 3" pipes from the cats back. I had them cut the pipes just after the cats and before they flattened the 2½" pipe at the Y. No resonators on mine now either. And I have true duals with 2 mufflers. And wow, what a difference it made. Now I just need to do a CAI and get a programmer.

Towing a 24' boat yesterday that weighed just over 5,000lbs up a 9% grade I got 12mpg. And it never struggled for one second. And I was running 60 mph to 70 mph. I'm running 3.73 gears and 305/60R18 Nitto Terra Grapplers. And had myself, my 2 teenage boys, my teen nephew, my sister and my dad and a crap ton of crap in the bed. Lol.

On the MDS, you can disable it by putting the transmission in manual 6th gear. But then again mine never kicks in here in WV.

Sent from my SM-N900V using Tapatalk

 

[Caldwell]

Donelam,

I did hear your exhaust, and I loved the sound of it !. If I made the move I think I would personally stick with a single exhaust. ( Y-pipe Mod, 3.5 into a Magnaflow Race Bullet, then 4'' out to a 4.5/5" tip. ) just like the " diesel look ".

considering your in the mountains region, do you feel the 6.4+3.73 still has great power ? I want 4.10's but feel that I would get murdered on highway mpg, and the 3.73's would shine in that aspect. NOT LOOKING FOR HYBRID MILEAGE ***** !!!!! but lets face facts who doesn't love an honest 17+ mpg on a truck if they can help it lol

 

[Soldier of The Law]

I'm kicking the same idea as you. Trade my 2011 1500 crew for a mega SLT 6.4. Was leaning towards 4.10 rear since I know I won't leave it stock

Would also do a dual setup on the exhaust. I have the muffler delete and can't have a quiet truck.

Also live in the Philly burbs and used to frequenting gas pumps.

Gonna get some pricing from a local dealer today. Will keep you posted.

 

[WhiteExpress]

Donelam,

I did hear your exhaust, and I loved the sound of it !. If I made the move I think I would personally stick with a single exhaust. ( Y-pipe Mod, 3.5 into a Magnaflow Race Bullet, then 4'' out to a 4.5/5" tip. ) just like the " diesel look ".

considering your in the mountains region, do you feel the 6.4+3.73 still has great power ? I want 4.10's but feel that I would get murdered on highway mpg, and the 3.73's would shine in that aspect. NOT LOOKING FOR HYBRID MILEAGE ***** !!!!! but lets face facts who doesn't love an honest 17+ mpg on a truck if they can help it lol

My try at exhaust on my '13 was a 18" 3" In/Out Maggy stepped up to a 4" Cummins tailpipe. D R O N E M O N S T E R !

Don't do it! It did look great, but holy ****, the standing waves that built in that 4" pipe where ungodly!

 

[arod412]

Caldwell, if you are not towing, I think you are fine. I would love to see one in person and ride with ya. I won't buy one, but I want to hear the roar of the engine. Test drive a 2500 with a 6.4l and test drive the ecodiesel.

 

[Caldwell]

AROD,

your right I don't really need one, but hey if I can safely afford it then why not ?. I have a lease at the moment anyway so I have to give my current truck back eventually. I do not want to roll into another lease. I'm only in my lease now cause my fiance' got laid off, and I took on all the bills last summer. my current truck doesn't have all the options I want, so if I can make the right move and get exactly what I want then im gonna make the move lol.

there are some new and used 5.7's / 6.4's around our area for reasonable prices that im willing to pay for. I was just curious if the power difference is that noticeable even with the 5.7L + 4.10's compared the the 6.4L

 

[NewBlackDak]

Donelam,

I did hear your exhaust, and I loved the sound of it !. If I made the move I think I would personally stick with a single exhaust. ( Y-pipe Mod, 3.5 into a Magnaflow Race Bullet, then 4'' out to a 4.5/5" tip. ) just like the " diesel look ".

considering your in the mountains region, do you feel the 6.4+3.73 still has great power ? I want 4.10's but feel that I would get murdered on highway mpg, and the 3.73's would shine in that aspect. NOT LOOKING FOR HYBRID MILEAGE ***** !!!!! but lets face facts who doesn't love an honest 17+ mpg on a truck if they can help it lol

Get the 4.10s. Check out the mileage thread, or look on fuelly(link in my sig). The 4.10s have been getting the same(or better in my case) mileage as the 3.73.

 

[Donelam304]

Yes, the gas mileage on 3.73 vs 4.10 gears is almost the same. And here in WV in the mountains I rarely hear the mds even kick on. All ya have to do if ya don't want it on is push the tow/haul button and it disables 6th gear and the mds. Or select 6th gear on the gear shifter and put it in manual mode and you have overdrive and no mds.

 

[KCTHUNDER]

curious, whats factory mileage city and highway for a 5.7 and 6.4 2500??

 

[regularcab2500]

heavy duty trucks don't get rated for fuel mileage.

 

[KCTHUNDER]

gotcha, was just wondering cuz obviously everybodys mpg will be different with towing, driving habits, etc. didn't know if there was stock numbers to base it off of. thanks

 

[regularcab2500]

those reasons are why they don't rate them lol they all get used differently.

 

[Ratket]

one thing to keep in mind.. this motor is new... there are a **** load of aftermarket parts available for the 5.7 and all of them are tested and true. So for some extra cash that 5.7 will out preform the 6.4. hell if it is enough of a savings u can even add a blower... I love my 6.4 but it's always something to think about.

 

[KCTHUNDER]

I drove a 6.4 today and loved it. I was just curious how they compare mpg without a load. if 5.7 would be better or work harder and not be much different. obviously 6.4 with pull anything for towing tho !