5.7L Vs. 6.4L 2500

[wyo2track]

The Aisin is already mated to the 6.4L as the standard transmission in the following Cab and Chassis models 3500, 4500 and 5500. Since at least 2014 it was an option on the 3500 cab and chassis and standard on the 4500 and 5500 cab and chassis.

It sure is. I believe the 6.4 is also derated in power from the standard 2500/3500 models in these applications because of duty cycles.

Yes it is, but what he is saying is it isn't efficient enough to put in the 2500's and 3500's where a few more people care about fuel economy than in the cab and chassis trucks.

Correct. And I'll take this a step further. I find myself asking the question, are manufactures willing to put in a bunch of R&D into a 8+ speed transmission for the 3/4 & 1 ton gasser market if the transmission cannot be used in the diesel application? After all, the 3/4 ton gasser market is a small piece of the HD pie and fleet sales most likely easily account for the bulk of customers. Us guys that love our 3/4 ton gas trucks are probably just a bonus. I just don't see a manufacture dumping a bunch of money into an all new tranny design that accounts for a small portion of sales. Hope I'm wrong. Its gotta be easy, like what Ford is doing with their new revised 6 speed going into the 2017 SD. It was easy for RAM to take the gear set out of the 68RFE and place it into the 545RFE case.

 

[wyo2track]

How much fuel economy would you loose, 1 maybe 2 mpg. I certainly hope no one really expects a 2500 or a 3500 with 6.4L engine to get good gas mileage anyway. I have 6.4L /3:73 I get like 13/18 so with the Aisin maybe a little less like 12/16 both suck, so to most I doubt they would raise an eyebrow. .

Your probably right. Seems the Aisin equipped diesels are about that amount lower than 6.7's with the 68RFE from reading all the forum reviews. Just more rotating mass to overcome. IMO, I don't think RAM would put a tranny in that would make the truck less efficient.

 

[smurfs_of_war]

How much fuel economy would you loose, 1 maybe 2 mpg. I certainly hope no one really expects a 2500 or a 3500 with 6.4L engine to get good gas mileage anyway. I have 6.4L /3:73 I get like 13/18 so with the Aisin maybe a little less like 12/16 both suck, so to most I doubt they would raise an eyebrow.

To a fleet buyer that might raise an eyebrow. Even for me, the thought of losing even more mileage on an already dismal efficiency is a bit gut churning.

 

[drittal]

After all, the 3/4 ton gasser market is a small piece of the HD pie and fleet sales most likely easily account for the bulk of customers. Us guys that love our 3/4 ton gas trucks are probably just a bonus. I just don't see a manufacture dumping a bunch of money into an all new tranny design that accounts for a small portion of sales. Hope I'm wrong. .

That piece is growing though. Fleet gasser sales around here are BIG! C&J Energy (nabors), Baker Hughes, Continental, BNSF Railway all use gas 2500/3500.

Nabors used to run dozens of powerstrokes. Now it's all Gas. Companies are tired of the issues and expense of diesels now days. The only alernative from Ram was a 360 magnum, or the 5.7 when it replaced it. Was the hemi ever available in the 3500?? As I drive around now, I notice a lot more gas HD than ever before.

A proper geared 6 or an 8spd with that can handle the HD requirements on their Ram gassers could help them nibble more business from Ford.

And why 3 transmissions and 3 power outputs on the cummins??? 1 output and 2 transmissions. Streamline...

 

[wyo2track]

A proper geared 6 or an 8spd with that can handle the HD requirements on their Ram gassers could help them nibble more business from Ford.

And why 3 transmissions and 3 power outputs on the cummins??? 1 output and 2 transmissions. Streamline...

I feel the same way!! Good thoughts. RAM does do a great job at giving their customers choices. Perhaps too much.... And most fleets around my area are HD gassers too. I really like how FCA jumped out and was the first to put the 8 speed in a truck. Had those other 2 manufactures following for a bit. Maybe they'll do it again in 2 or 3 years, this time in the HD arena ....

 

[SouthTexan]

I feel the same way!! Good thoughts. RAM does do a great job at giving their customers choices. Perhaps too much.... And most fleets around my area are HD gassers too. I really like how FCA jumped out and was the first to put the 8 speed in a truck. Had those other 2 manufactures following for a bit. Maybe they'll do it again in 2 or 3 years, this time in the HD arena ....

I don't see having an 8 speed in the 1500 made the others follow. The 8 speed in the Ram still didn't increase any capabilities. In fact it lowered them in some cases and remained the same in others which is why if you want to tow the max a Ram 1500 is rated for then you would have to get one with a 6 speed not an 8 speed. Nor did the 8 speed increase any performance and the competition with their 6 speeds . Not only did the F150 EB 3.5L with a 6 speed outperform the 1500 Hemi 5.7L with an 8 speed in every performance test, but it also got better fuel economy doing it. So I don't so how the others would be following.


I think that while an 8 speed mated with 6.4L in the Ram may allow it to tow better, it might come at the cost of less capability. The only way to add gears in an automatic while keeping the external case the same size is to make the internal parts smaller which would inherently make them weaker in most cases. Smaller clutches also have less friction area, and less friction area makes it more susceptible to slip. More slipping creates more heat, and heat ruins a transmission fast which is why most tow vehicles have transmission oil coolers. Nothing causes an auto transmission to slip more than towing heavy loads with a high powered engine. You might see a tow rating drop with the 8 speed although most 6.4L owners probably don't tow anywhere near the 15,500 lb rating anyways.

 

[regularcab2500]

not sure how a stock eco could be faster than a hemi 8sp with 3.92s. guy at work leased a 2014 ecoboost and thought his truck was hot **** till i pulled away from him from a stop on niagara falls boulevard near the 290. when i let off at 80, his nose was behind my tailgate. obviously didnt run away from him too much but he certainly was never gonna get me. he abrubtly stopped talking **** to me as well.

as far as the OP which i believe i have already commented on, i see no reason why ram even sells the 5.7 for heavy duty trucks anymore. my only request, although this would not be very popular for consumers, would be a G56/6.4 hemi combo. if i could get a manual gasser i wouldnt even consider diesel in the future. that is unless Caterpillar starts putting a smaller I6 in pickups. if they started doing that i wouldnt even care what brand i was driving (except toyota lol)

 

[warwagon98xj]

I have the 5.7 in ccsb 2500 and i love it but then again i came from a 06 f250 with the 5.4 so the 5.7 is a powerhouse to me

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[SouthTexan]

not sure how a stock eco could be faster than a hemi 8sp with 3.92s. guy at work leased a 2014 ecoboost and thought his truck was hot **** till i pulled away from him from a stop on niagara falls boulevard near the 290. when i let off at 80, his nose was behind my tailgate. obviously didnt run away from him too much but he certainly was never gonna get me. he abrubtly stopped talking **** to me as well.

It is quicker by personal experience of my 2012 crew cab 4wd Ecoboost 3.55 going against my brother in law I my sister's 2013 crew cab 2wd 3.92 at the track. I also raced two other Ram 5.7L that day, but I raced those with my tune and had a considerably larger lead than what I did with the less than a truck length I had with my brother in law running stock.


There are also other sites that prove the same like the last time Pickuptrucks.com took both these trucks to the track.


2015 F150 3.5L EB 6 speed 3.55
Vs.
2015 Ram 1500 5.7L Hemi 8 speed 3.92

0-60 unloaded
F150 - 6.22 seconds
RAM - 6.68 seconds

Quarter mile
F150 - 14.84 @ 94 mph
RAM - 15.12 @ 92 mph

Davis Damn 6.8 grade 0-60
F150 - 20.76 seconds towing 6,800 lbs
RAM - 26.15 seconds towing 6,700 lbs

Fuel economy
F150 - 18.5 mpg using regular 87 octane
RAM - 16.4 mpg using midgrade 89 octane

 

[theviking]

Not sure why any of this stock vs. stock benchmarking matters so much. Anyone who really cares will be modifying there vehicles anyway.

But for what it's worth, Ford apparently chose not to use the EcoBoost engines in their new 2017 HD trucks. No idea why, but it seems to give validity to some of the concerns mentioned over heavy towing with the EB motors.

 

[avolnek]

But for what it's worth, Ford apparently chose not to use the EcoBoost engines in their new 2017 HD trucks. No idea why, but it seems to give validity to some of the concerns mentioned over heavy towing with the EB motors.

they aren't using it in the heavy duty line up as it isn't a heavy duty motor and anyone who will tell you a 3.5L v6 is any different is a fool...

yes it is impressive what they are towing with them but that doesn't prove to be "heavy duty"

 

[Csanders1992]

I had rumors of an ecoboost in the hd line but I heard it was a bigger motor than the 3.5


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[avolnek]

I had rumors of an ecoboost in the hd line but I heard it was a bigger motor than the 3.5


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i think i turbo charged gas engine would be huge step forward if they could get it to hold up to the HD standards... With the EPA cracking down on diesels many people are looking at the gas engines... as of right now they still lack the overall torque to suit the needs of many but if you could up it with a turbo and run it reliably that would be freakin sweet!

 

[rayz]

I have a '15 Power Wagon,6.4L I "jumped "on it the other day...o.m.g.....why you would want more power is beyond me....

 

[SouthTexan]

Not sure why any of this stock vs. stock benchmarking matters so much. Anyone who really cares will be modifying there vehicles anyway.

But for what it's worth, Ford apparently chose not to use the EcoBoost engines in their new 2017 HD trucks. No idea why, but it seems to give validity to some of the concerns mentioned over heavy towing with the EB motors.

If you modded the Ecoboost then it would be more in the its favor unless you spend over $6,000 on a supercharger on the Hemi 5.7L. With just a $450 SCT tuner with custom tow tunes, I was putting down around 370 hp and 460 lb-ft of torque at the wheels on the dyno(that is about 410 hp and 530 lb-ft at the crank). This was with the very same tow tune that I towed 9,500 lbs up and over the Rockies twice without ever being more than 5 mph under the speed limit at very steep grades. I even went up where they did the Ike. It just pulled along at 65 mph in 4th at about 2,900 rpm and then it got to the the steep parts it would slow down to about 63 mph then kick in 3rd gear to at about 3,800 rpm to get you back up to 65 mph. If I would have left it in 3rd, then I doubt it would have even dropped back.

To those that say it does not belong in the HD world clearly have never driven one or know what they are talking about. Why Ford didn't put in the new Super Duties I don't know and any guess would be speculation only. Maybe it had to do with emissions certifications or maybe it had to do with the fact that the 6.2L (which was only first released a few years ago) still hasn't payed for itself yet especially since it is only offered in Super Duties now that it is no longer offered in the F150. Whatever the case may be, I have no doubts about the 3.5L Ecoboosts being able to reliably handle the life of an HD knowing how it was tested, what it's internals are made of, and from seeing a fleet of them get used and abused towing or hauling every day.


Oh, and the 3.5L Ecoboost is already offered in commercial "one ton" Transit 350HD vans with a GVWR of 10,360 lbs.

 

[smurfs_of_war]

You're right. Speculation. One speculation is marketing. Ford is already cannibalising their F250 market with the F150.

I do have to question the duty cycle of the ecoboost. No questioning the power output, but I would wonder if it could do that day in and day out being flogged like a mule like the 6.2 can.

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[SouthTexan]

You're right. Speculation. One speculation is marketing. Ford is already cannibalising their F250 market with the F150.

I do have to question the duty cycle of the ecoboost. No questioning the power output, but I would wonder if it could do that day in and day out being flogged like a mule like the 6.2 can.

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True, but if you looked at it's internals compared to other V8 engines it competes with. A lot of people ignorantly think that being a six cylinder then it will be more stressed. Those people are taking naturally aspirated logic and placing on a forced induction engine.

It kind of reminds me of the tales of when the 5.9L Cummins six cylinder turbo diesel came out and it was being compared to the larger displacement naturally aspirated V8 diesels. All the V8 Ford guys said it wouldn't be reliable, or that it wouldn't hold up to the duty cycle of a heavy duty, or that turbos would lessen its reliability. How did their assumptions pan out?

As I said, if you take a look at the 3.5L Ecoboosts internals and compare it to V8s like GM's 420 hp and 460 lb-ft 6.2L. The 6.2L has a higher 11.5:1 compression ratio than that of the 10:1 of the 3.5L EB. The 6.2L uses a weaker cast-in iron cylinder liners compared to the Ecoboost stronger steel cylinders liners which are used in most diesels. The 6.2L uses only four bolt mains to hold the crank while the 3.5L uses six. The crankshaft and piston of the Ecoboost are forged steel while the 6.2L connecting rods are forged powder metal. So it is definitely "overbuilt" to handle the stress even with it's turbos just diesels are "overbuilt" to handle the much greater stresses that the Ecoboost engine goes though.

Then there is the fact of what kills in engine which is speed(rpms) and heat. It is a known fact that constant high rpms will lessen an engine's life. Parts are having to move faster which hinders their longevity. With high rpms adds heat if the oil and coolant cannot shed enough heat off the internals quick enough. If you took at 5.7L Hemi 6 speed found in the 2500 and a 3.5L Ecoboost in an F150 and towed 10k lbs across country, I would guarantee that the 5.7L Hemi would have a higher average engine rpm than the 3.5L Ecoboost. This is because the Ecoboost makes it's power at a much lower rpm, and does not need to rev as high to get the pulling torque it needs. It basically does not have to work as hard to do the same work. If you have an engine that is built to handle the stresses of forced induction without the need to have to work as hard to do the same job, then you have a recipe for a reliable work engine.

 

[theviking]

Still, the fact remains they chose not to launch the an EB motor. Considering how Ford is marketing these engines, it's pretty surprising and there must have been some compelling reason. Since we're speculating for fun here I'd guess it would have to be one of a few reasons.

Hard to sell HD truck guys on a weenie (and tinny sounding) 3.5L motor, no matter how good it may be.

Heavily boosted turbo motors generate a lot of heat, which can be hell on parts. May have had trouble passing all HD durability tests. Don't care how well it's built, compared to a big NA iron block motor there is a lot more to go wrong.

About everyone reports fuel economy goes to hell when towing heavy loads with the EB. Perhaps they just couldn't get the numbers they wanted for an "Eco" motor.

I think the Holy Grail to HD Ford fans would be a mildly boosted EB 5.0 motor. Sort of like how we pray for a 6.4HD motor with 450hp/tq and an 8 speed. Both probably won't happen any time soon, but we need something to complain about

 

[Ratket]

you can't shove a twin turbo ecobost 3.5l v6 in a had truck. Towing with max pay load with one is nuts.. the truck just doesn't weigh enough. They have the play form with the 5.0 to convert it to a ecobost .. twin turbo v8..prolly 550 in change hp with 650 tQ.. I would trade my truck in a heart beat.. tune the ****** and cai with exhaust now it is 660-700 hp with 800tq- sign me the **** up lol.. Eco boost are awsome, we towed my buddies 28ft toy hauler fully loaded.. every big gust of wind and my but hole was puckering... thing had power for days.. no way ford puts on in a hd truck though.. Or if they do.. no one is gonna buy it.. at full pay load you could t keep the front tires on the ground. I looked real hard at a f250 with a 6.2 and having a whipple installed.. but ford wants to much money for their trucks.. I will just wait till the Eco boost the 5.0 in a hd.. hopefully it happens.. in 5 or so years.. so I can talk the wife into letting me trade lol.

 

[SouthTexan]

Still, the fact remains they chose not to launch the an EB motor. Considering how Ford is marketing these engines, it's pretty surprising and there must have been some compelling reason. Since we speculating for fun here I'd guess it would have to be one of a few reasons.

Hard to sell HD truck guys on a weenie (and tinny sounding) 3.5L motor, no matter how good it may be.

Heavily boosted turbo motors generate a lot of heat, which can be hell on parts. May have had trouble passing all HD durability tests. Don't care how well it's built, compared to a big NA iron block motor there is a lot more to go wrong.

About everyone reports fuel economy goes to hell when towing heavy loads with the EB. Perhaps they just couldn't get the numbers they wanted for an "Eco" motor.

I think the Holy Grail to HD Ford fans would be a mildly boosted EB 5.0 motor. Sort of like how we pray for a 6.4HD motor with 450hp/tq and an 8 speed. Both probably won't happen any time soon, but we need something to complain about

It was also hard to sell the six cylinder turbo charged Cummins in a market dominated by naturally aspirated V8s too. But how did that turn out? Although you may have a point about the perception some may have. I know when the engine first came out in the F150 it was an up hill battle on proving the engine. Oddly people are more worried about the noise an engine makes or how many cylinders than actual power. They would rather have less usable power over noise. Then there were the ones with the false mentality of "there is no replacement for displacement" when the correct mentality should be "there is no replacement for effective displacement ". Then the "good old fashioned V8" crowd that thought the modern V8s were just like the old ones. Even worse, if those people were to ask their grand dad then he would probably say "good old fashioned 6 cylinder" since they were the only choice in many trucks before V8s. Hell the first Power Wagons only came with a 230 ci (3.8L) 6 cylinder engine.

I am not with you on is the reliability thing. Yes, compressed air does create heat, but it does not mean a thing unless the engine oil and cooling system can manage that heat. With Ford running the 3.5L Ecoboost for 15 days straight at wide open throttle in their testing and it still held up to that heat while passing then I think it can handle running at wide open thottle when towing for a few hours(not like it needs it). Then was the shock test of running the engine at wide open throttle for 10 minutes getting the turbos up to 1,800 degrees and then immediately shutting of the engine to halt all oil and coolant going to the turbos. This was repeated 1,500 times on the same oil with the turbos and engine passing spec. I know the tor ture testing g this engine went through is a lot more than almost all HD truck owners will put their trucks through so this is why I say that I am not with your on the reliability assumption.


On the fuel economy when towing thing, I have to call BS to that. Every naturally aspirated V8 that I have ever driven gets horrible fuel mileage when towing and I would not think that a turbocharged V6 would be any different. I have heard people talk about the 3.5L EBs fuel mileage when towing many times acting like a V8 gets great fuel mileage when towing when I know for a fact that they don't. Another thing that debunks that myth is not only did the 3.5L EB get better fuel economy than the Ram 5.7L 1500 towing in both of the PUTC they were in, but it also got better fuel mileage in the Canadian Truck Challenge as well when towing the same weight. In that PUTC test that I posted the performance numbers for earlier, the 3.5L Ecoboost got 11.1 mpg towing a 6,800 lb trailer and the 5.7L 1500 got 9.7 mpg towing the same load so I will call bull to that.

Although the one thiing I will say is that Ford has been notorious here lately of not introducing new engine with new models. They have been waiting a couple years after the new model comes out to reenergize sales. That is the same thing they did with the F150 when it was a new model in 2009, but used the old engines until 2011 when they came out with all new ones. Rumor has it that they are coming out with a Gen 2 420+ hp 3.5L Ecoboost in 2017 for the F150 which is two years after its 2015 new model debut. They did this for other cars as well and can see how it could stimulate sales with those who always want the latest and greatest. Who knows, we may see a new engine line up in the Super Dutis a few years after its release.