5.7 hemi engine comparisons

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Bladesmith

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Ram Year
1997
Engine
5.9
I have an old 1997 2500 ram with a 5.9 gas engine, I'm thinking about trading up to a new 2018 ram 2500 with a 5.7 hemi. I do pull a RV 5th wheel ( dry weight 7,000) occassionally on short trips ( 70 to 100 miles) from home. The old 5.9 does a good job with no issues so are these 2 engines comparable. Does the new 5.7 hemi have better tor. and HP then the old 5.9? Or do I need to move up to the 6.4 hemi to be more comparable? I don't care about being macho needing a bigger engine just because its there, I just need to know if the 5.7 hemi will do the job the 5.9 did with as good or maybe even a little better results.

Thank you for all info
 

Arth

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2022 Ram 3500 Crew Cab Limited 4x4
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6.7 HO Cummins Turbo Diesel
I have an old 1997 2500 ram with a 5.9 gas engine, I'm thinking about trading up to a new 2018 ram 2500 with a 5.7 hemi. I do pull a RV 5th wheel ( dry weight 7,000) occassionally on short trips ( 70 to 100 miles) from home. The old 5.9 does a good job with no issues so are these 2 engines comparable. Does the new 5.7 hemi have better tor. and HP then the old 5.9? Or do I need to move up to the 6.4 hemi to be more comparable? I don't care about being macho needing a bigger engine just because its there, I just need to know if the 5.7 hemi will do the job the 5.9 did with as good or maybe even a little better results.

Thank you for all info


So if you've got a 97 with the 5.9 you are looking at roughly 245HP and 340 torque.

The 2500 5.7 Hemi you are looking at has 383 HP and 400 torque. The 6.4 Hemi gives you 410 HP and 429 torque.

Basically any new truck will blow your 97 out of the water and get better MPG doing it I bet.

I would go to the dealer and give one a test drive to see if you think it's worth it. On paper it will be an easy choice due to the advancements in safety, towing tech, and just general improvements that have been made over the years.
 

pacofortacos

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2016
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5.7
My 5.9 in my 01 quad cab Dakota towed much better than my 5.7 hemi in my 16 Ram CC.
The 5.9 had much more low rpm torque.
The 5.9 had 3.55 gears, the 5.7 has 3.92 gears.

That being said - if you let the hemi rev it has much more high rpm power than the 5.9 and the 8 speed transmission is, well, just about perfect.

My ideal truck would have been that dakota body with a tuned 5.9 and the 8 speed trans :)
 
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Bladesmith

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I'm sure hoping a new 5.7 would get better MPG, my old 5.9 only gets about 14 MPG empty, towing it drops to 8-9. Its been 21 yrs, since I've looked at new trucks so thats why I asked you more knowledgeable folks for help. Dealers are liable to tell you anything so its good to hear from those that actually own and use these trucks.
Thank you all.
 

pacofortacos

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It really depends on where you live, how you drive, winds, and your ave. trip length.

deleted

Sorry, just noticed you are looking at a 2500, the above is for a 1500 so ignore it. LOL
 
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huntergreen

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2016
Engine
hemi 5.7
I'm sure hoping a new 5.7 would get better MPG, my old 5.9 only gets about 14 MPG empty, towing it drops to 8-9. Its been 21 yrs, since I've looked at new trucks so thats why I asked you more knowledgeable folks for help. Dealers are liable to tell you anything so its good to hear from those that actually own and use these trucks.
Thank you all.

I doubt you will see much of an improvement in mpg, but you will have a heavy duty truck. You might get maybe 2 extra mpg. I would suggest the the 6.4 with the 4:10 gear ratio.
 
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Bladesmith

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5.9
Why the 6.4 over the 5.7, is there really that much of an advantage with an additional 26 or so more hp. I have 409 gear ratio in this old truck and there a mileage killer. My father had an older 2500 chevy with 373 gears ( 350 motor) and his truck pulled just as well and mileage was 3-5 MPG better. I know the newer technology of today should be better performing then that of 20 yrs. ago but whats the advantages with a 6.4?
WOW arth, I just reread your post I had no idea there would be 138 more hp difference in todays engines approximately the same size. Thats amazing.

Thanks guys, I really appreciate all your knowledge and opinions
 

chrisp2493

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It’s not just about the 26 extra hp at peak output. The 6.4 has much better low end power being the bigger engine then the 5.7. Plus that motor is a much heavier built engine, stronger internals then the 5.7. It’s set up for heavier trucks and pulling more. It will completely blow the old 5.9 out of the water, no question about it. Let alone the newer transmissions compared the the old 4 speed you have.


I Bleed Ram Trucks
 
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Bladesmith

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5.9
Thanks Chrisp, but I'm not to worried about pulling hugh loads but I do want a motor that will hold up. If I was going big loads I'd go 6.7 cummins. I'm just looking to figure out if the 5.7 will be satisfactory for what I need and not give me headaches . There's so much over kill out there, and some might say you should just go with the big boy engines because then your covered no matter what, only problem with that reasoning is all these big boy upgrades come with an increased price, so I really don't want to spend for over kill if I don't need it. I see that the 5.7 hemi came out in 2003 to replace the 5.9 mag so I'm assuming its very comparable and even better then the 5.9 that I now have, but does the 5.7 have a good track record for holding up as well as the 5.9. My old 5.9 has only needed the plemum plate gasket replaced in 21 yrs. so is the 5.7 as tough as the 5.9, or is that the reason dodge came out with the 6.4. Dodge transmissions use to be garbage, I don't know what there like now, but, 80,000 to 90,000 miles were usually there life expectency, mine crapped out at 85,000, so I'm just researching trying to figure out whats good or what I should stay away from.

Thanks guys I do appreciate your opinions.
 

slim chance

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lancaster, pa
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2023
Engine
hemi 5.7 eTorque
i had the 5.9 in several dodge trucks and IF you are happy with that engine, as i was, you will be VERY happy with the 5.7 hemi ... for towing i would get the 3.92 rear
 

Fitz-0518

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Have had 4 5.7 hemi. The 6.4 is a true truck engine and a great fit for the 2500.
 

chrisp2493

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There are several threads on here with a ton of info comparing towing between the 5.7 and 6.4 motors. Just a heads up the 6.4 is only available in at least a 2500 truck so if you plan on staying with a half ton the 5.7 Hemi is hands down the best option. The new 8 speed transmission has proven to be a very solid and strong transmission, generally everyone is very happy with it. With some proper care you should expect them to last a good 150,000 miles if not more. The main issue lately has been some trucks having trouble with the camshafts and lifters, we have to wait and see if the brand new trucks have that issue, that doesn’t seem to happen until after 100,000 miles though


I Bleed Ram Trucks
 

dapepper9

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Before you go to the dealership, call and ask if you can bring your trailer to see if the towing capability of there new trucks will make it worth buying. Say you wanna compare the 5.7 and 6.4
 

Don Williams

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v10 8.0
Hi there,
I had an 05 Ram Quad Cab 1500 Hemi with5.7, 392 gears, and 20 inch tires. I pulled a 32 foot toy hauler with it for about 8 years. It did OK. The Hemi had good power and the 5 speed transmission was good. I never had any transmission problems. I decided I wanted a heavier truck. Although the TH weighed about 8K loaded up with a toy, it was pretty close to towing capacity and payload capacity on the truck. If I had the money, I would look at a newer truck and it would be a 2500 with a 6.4. My funds being what they are, I found 99 Ram 2500 with the 8.0 V10. Although the truck doesn't have the horsepower numbers a Hemi has, it's torque rating is 450 and the torque range is wide. As it is it compares very favorabley with a 5.7 hemi. I would love the extra gears in a newer transmission though. I know the gas mileage sucks but for the difference in pricing, I can buy a lot of gas. If I were you, and I had the funds for a new truck, I would definitely go for a 2500 with a 6.4 engine. A 2500 has better brakes and axles not to mention a heavier frame. In the long run you will be happier with that.
 
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Bladesmith

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1997
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5.9
Thanks everyone for the comments. I've owned 2- 2500 dodge trucks in 30 yrs. and both held up great and I owe that to them both being 2500 models. They are built a lot tougher then 1500s so where I live and what I tow I would never go back to a 1500. So my wife and I went to a dealership yesterday and was looking at a 2500 4x4, crew cab with a 6.4 and the price was pretty reasonable, but after further review the truck didn't have the anti slip rear end, trailer break controller or the 5th wheel tow package which I was really hoping for, so we passed on that one. I will say that I remember now why I haven't traded trucks in 21 yrs.- car dealerships and their salesmen are a very unpleasant experience, we arrived at the dealership around 2:30 and they jimmed us around for over 2 hrs before they would actually give us their lowest bottom dollar price which was almost $3000 less then their starting price . This really didn't sit well with my wife, who said that was a nightmare, why don't they just give you their best price and say take it or leave it, instead of mickey mousing you around for several hours. All I could say was, thats the games they play, so you just need to beware. We'll keep looking, though we're not looking forward to going thru that again.
 
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