6.4L Hemi vs 7.3L Ford Gasser-either in a Dually

[HEMIMANN]

Thought Duramax (actually Isuzu) was ok after they had the original injector problem solved way back? I think the diesel engine makers have the HPCR Bosch CP4 pump durability problems now?

 

[retired]

4000 to 4300, that's basically peak torque. Your engine has nowhere left to go to make additional power. Maybe we have different definitions of "screaming" but pick a different word then; WOT, full power, whatever the case is, that engine is working as hard as it can, which is my point.

When my truck is empty and I'm in the city or on rural roads, I can go weeks without exceeding 2100 rpms, and that's keeping up with traffic while accelerating, or getting onto freeways etc. 4000 rpms in my truck is a really really rough day while towing anywhere between 5000 to 7000 pounds, I almost never need to touch 4000 even while accelerating while towing, and I've definitely never sat there for minutes on end.

It is still making additional horsepower to like 5800 rpms give or take.

 

[ramffml]

It is still making additional horsepower to like 5800 rpms give or take.

When you're towing, torque is king. That's why you're engine won't sit at 5800 rpms (unless you force it or have like 4 gears in your transmission). If you have an 8 or 10 speed and are trying to tow up a hill, your engine will sit around or slighty above peak torque, not peak HP.

 

[mtwofeathers]

Hello. Looking for real world comparisons of these two drivetrains. I have had the 8 speed, so I know it is absolutely the bee's knee's, but, I am enamored with the higher output of the 7.3L Ford. I think the Ford 10 speed has a lot of promise, but I am not convinced that it is on par with the 8 speed. Same situation, but in reverse on the engines. I have a 5.7L hemi that has given me good service, but the 6.4L seems to be derated for the trucks. Why? The 485HP that they make in the SRT vehicles would do a lot to persuade me toward a Ram, but the 6.4L in the trucks only has 410hp. I looked at the torque curves of each 6.4L engine, and there are no answers there either. The higher horsepower SRT version makes great torque down low.

I am going to buy a 350/3500 dually crew cab long bed truck. I already put a deposit down on a Ford. I am getting very shakey about it though, as there is report after report about rear end/transmission noise and several people have posted pictures of low mileage trucks with metal contaminated rear end oil. Numerous people are saying that there is a grinding noise when shifting from 5-4 or 5-3 or 4-3 while slowing down. No one has pinpointed where this is coming from, there are NUMEROUS trucks that have already been back in to the dealer for this noise and several have been advised that new rear ends are needed. This is in ADDITION to a M275 Dana Axle recall that Ford already has underway due to thin castings at the spring mount.

I know my Jeep had DANA axles, do these Ram 3500 4.10 rears have Dana axles? I know that Dana typically makes excellent axles, but you can forgive me for being very cautious about this issue. There are already active recalls in place, and now there are numerous verified issues that Ford has NOT addressed.

I've had great luck with the prior 4 Chrysler/Jeep purchases that we've made, and I'm considering a fifth now.

This truck will be used primarily to tow 16-20,000lbs of tractor around a radius of about 70 miles of foothills at speeds of no more than 65mph.

Please comment as you feel necessary. Thanks.

12 inch AAM rear axle, AAM was awarded the contract for 2022 to 2230.

 

[huntergreen]

Thought Duramax (actually Isuzu) was ok after they had the original injector problem solved way back? I think the diesel engine makers have the HPCR Bosch CP4 pump durability problems now?

All engines have their unique issues. Friends of mine tow their super huge 5th wheel here every summer. 2017 duramax, nearing 100000 miles, other than maintenance, 0 issues. They go all over the country. My thoughts are, when worked like this, you avoid all the issues common to modern diesels.

 

[HEMIMANN]

All engines have their unique issues. Friends of mine tow their super huge 5th wheel here every summer. 2017 duramax, nearing 100000 miles, other than maintenance, 0 issues. They go all over the country. My thoughts are, when worked like this, you avoid all the issues common to modern diesels.

Yup - applying the diesel for its intended purpose - not a short trip grocery getter. I got a little Yanmar diesel in my compact tractor. @ 1,500 hours & 9 years old, app. 1,200 of those hours are heavy mower deck mulching of grass and leaves. I'd be burning through app. 2x the amount of gasoline in a gas engine. I know because I used to have one of those, too!

But for my Ram 2500, my 6.4L Hemi is just right for part time towing. Yeah, I cringe when I squeeze the fuel pump multiple times when I do tow, but underworking a diesel the 95% of the rest of the time ain't right.

 

[huntergreen]

Yup - applying the diesel for its intended purpose - not a short trip grocery getter. I got a little Yanmar diesel in my compact tractor. @ 1,500 hours & 9 years old, app. 1,200 of those hours are heavy mower deck mulching of grass and leaves. I'd be burning through app. 2x the amount of gasoline in a gas engine. I know because I used to have one of those, too!

But for my Ram 2500, my 6.4L Hemi is just right for part time towing. Yeah, I cringe when I squeeze the fuel pump multiple times when I do tow, but underworking a diesel the 95% of the rest of the time ain't right.

Nothing wrong wrong with the 6.4 you have. With the way you're using it. The right truck for the right job.

 

[2020PW]

Personally, I would go 7.3. I’m in my 3rd 6.4, nothing wrong with them but nothing to write home about.

You will have issues with any brand.

 

[bcbouy]

i love reading about all the diesel owners telling everyone they're wrong.my uncle pulled a 26 ft. cabin cruiser for years with a pontiac station wagon.guess he was really wrong.not everyone wants a diesel.

 

[retired]

A few days ago I did 400 miles in a new F250 with 7.3 and 4.30 gears. I will say it is a much better drive train then my 2020 6.4 with 4.10's. If I were starting with a clean slate and going to be towing anything that is what I would get. We drove mostly 75mph and overall hand figured mpg was 14.6mpg and the truck was new I think it might have had 400 miles on it at the start of the trip and went from Missoula to Great Falls and back so always a stout wind. Ram needs to up their game in the gasser department.

 

[BadHemi2014]

i love reading about all the diesel owners telling everyone they're wrong.my uncle pulled a 26 ft. cabin cruiser for years with a pontiac station wagon.guess he was really wrong.not everyone wants a diesel.

I bet that wagon weighed more than my truck does!

Cars and men were tougher then.

(But I agree, diesel is not often necessary, got to fit the tool to the job.)

 

[Bldrinker]

My 6.4 6 speed with 4:88 handled 13k easily. Except for MPG lol
I’m sure the 6.4 8 speed would be ok with 14k maybe get by with a 15k load.

20k? No freaking way.

Buy a diesel.

 

[Cummins diesel]

I would definitely buy a diesel if you are pulling that kind of weight. Your truck will thank you.

 

[DJ18hemi1500]

Is the OP around the forum or did he just join to ask for opinions and then not want to listen to them?

 

[ramffml]

Is the OP around the forum or did he just join to ask for opinions and then not want to listen to them?

Hover your mouse over his name, he showed up last mid nov.

 

[DJ18hemi1500]

Hover your mouse over his name, he showed up last mid nov.

Thank you, that is a useful tip!

 

[Dodge trucker]

Ford has a 7.3 GAS engine out? Did they bring the 460 back?

 

[huntergreen]

Ford has a 7.3 GAS engine out? Did they bring the 460 back?

Supposedly newly designed.

 

[GonnaBuyaDually]

So I finally got my truck in; an F350 crew cab gas 7.3L 10 speed dually XL with 4.30 rear & 4 x 4. I put the small equipment trailer behind it (maybe 3500lbs) and my tractor with implements on it (7500lbs) and I took it from our remote property to our new house 40 miles away. In that trek, there is a 6-8% grade road that might be 1/2 mile - 1 mile long. In my first go at it, my truck made the hill at 61mph in 5th & 6th gear at about 4300 & 3600 rpm respectively. It was able to pull it in 6th gear, but the cruise allowed it to lose enough speed on the entry that it downshifted to 5th right away to regain the speed and then recovered to 6th gear at 3600rpm for the last half of the hill.

So it was able to pull 11k up a 6-8% grade in 6th gear at about 3600rpm doing 60mph. That was pretty bad ass imo, and it far exceeded the towing performance of the 20 year old diesels that I mentioned in the op that could barely manage 45mph up that same hill. I would bet a crisp $100 that it will outperform my fil's 2005 6L F250 diesel also.

That hill is the worst that this truck will see. Granted I was using the small trailer, and undoubtedly the big one would have netted a much tougher result from the gas engine. It will likely be a long time before I have that comparison.

I have video taped that pull, because there isn't enough available online for this new gasser for prospective new buyers to look at for evaluation, and when there is a video posted, some people want to say it isn't real before they even watch it. It will be a few days before I'm able to upload it.

This gas engine will be sufficient for my needs and the truck has been an absolute pleasure and has exceeded my expectations in nearly every way. I love it. Ram, time to get on the ball will a comparable gas engine! That is the only thing that drove me to buy my first Ford ever! The engine and transmission combo! I'd take a Ram with the 8 speed, but the comparable engine doesn't exist yet.

Here's a picture for your enjoyment;

 

[GonnaBuyaDually]

And one other thing I forgot to mention; you keep talking about the 4.30 as if that is going to change anything. It's not. That just helps you get moving off the line from a stop. In that video from Colter or whatever his name is, he was screaming in 5th, 6th etc, well beyond whatever benefit a super short first gear gets you. You have 10 gears in that truck, a 4.30 only helps you in one of them. Beyond that, as long as you have room to downshift, 4.30 won't change the picture whatsoever, your transmission (10 gears!) does whatever it needs to do to put you at peak power.

You obviously don't understand how rear end gearing works. Every single gear of the transmission is affected by the rear end gear. 6th is lower going through a 4.30 rear than a 3.73 rear, 4th is too, so is 1-10. All gears benefit from the lower 4.30 rear end gear.

Glad I could clear that up for you.