Which is better for fuel economy 3.6L V6 or 5.7 Hemi

Helping my son in law purchase a new 2022 Ram 1500. He does mostly highway driving to work, I'd say 70/30 split. What would be the most beneficial for fuel economy, the V6 3.6L or the 5.7Hemi.
Some people are telling me the Hemi shuts to 4 cylinder over 50, so that would be better, I'm saying well their highway driving specs do not reflect that, it has the V6 about 3-4 mpg better.
I know actual experience is a lot different but for now lets just stick with the advertised numbers.
What do you think?
thanks

real world it is not much difference, the V6 will get maybe 1 or 2 better mpg. The other thing to consider though is whenever you go to sell it the V6 brings a ton less than a hemi and will easily make up for any fuel savings.

The only reason to buy the V6 is to save a few bucks on the initial price.
Resale will take a hit. Gas mileage isn't much better. Towing capability will suffer.

Have him ask himself to weight all the "benefits" of having a smaller motor in a 5,000 lbs vehicle.
JUST GET THE HEMI!!!

I have 2 friends that bought V6 Rams....they both regretted the purchase. Underpowered and as stated...poor resale.

I've had 3 Ram 4wd 4 door trucks in the last 5 years. All 3 Hdmi 8 speeds. Highway mileage has been between 19 to 22 depending on rear gear. My 2021 gets 20ish with a 3.92 rear.

I have a Pentastar in my charger and it's a sweet little motor. 300hp, perfect sedan engine. But it has no place in a 1/2 ton, and I can't imagine a factory cam change for a truck application would have made that much better.

I have a 2012 ram 1500 sport, quad cab. 5.7 hemi and in real world I get 18.5 to 19 average pretty consistently
Just took it to Reno Nv recently draging a trailer. , Loaded it averaged 14.5 and pulled it like it wasn't there

When i was looking last year I wanted a 2006 to 2008 Truck but couldnt find anything that was decent ,shape and decent miles and not priced in the stratosphere
So started looking at the 09 and up trucks, as soon as I saw V6, clicked off and kept looking I didnt care price And they are cheaper, quite a bit cheaper for a reason

Sorry for suggesting something off topic but since fuel economy is one of your son's concerns I'm surprised that he's not considering an EcoDiesel. Pretty much the same towing capability too.

Lots of good points here, I didn't think about resale that is a big one to consider. He says its a 10 year buy, so resale might not be a big issue if that turns out that way.

I have a 2011 with the 5.7, bought it to tow a car trailer, never did get around to getting one, so I understand why he is considering this, no plans to ever two anything more that a landscape trailer. But you never know.

Anyhow I'm going to send him a link to this thread so he can think about this.

Thanks again

The 6 would be my first choice in the Chargers/Challengers. It is very peppy and gets good mileage. No need for one of the Hemis unless it is just something that someone has to have for vanity's sake.

But the trucks are Hemi territory. Looks like 2 to 4 MPG difference between the 6 and Hemi. Big torque difference. Big difference in resale. In fact, the 6 is a very limited market.

At $3.70 per gallon the 6 could save about $24 per thousand miles (20MPG vs 23MPG). That is the only possible advantage to driving a 6 cylinder powered full sized truck. And that could be optimistic.

But the trucks push a lot of air. So the faster the truck is driven, the less the MDS can drop the cylinders. If the driver likes speeds about most speed limits, the mileage will suffer. My 2019 2wd 5.7 Ram will get 19.5 to 20.4 average at and below 70. But it starts to drop off over that. And against a head wind. And up hills. And stop and go really eats into the mileage.

I don't have much experience with the 6s in trucks personally. We had one a few years ago and liked to have never sold it. So no more of them here.

www.fueleconomy.gov/feg/bymodel/2022_Ram_1500.shtml

I wouldn't know much about a half ton truck, but my 2015 5.7 Hemi 4x4 is lucky to get 17 mpg going 55 with a tail wind. The difference in the horsepower, torque, and weight has a lot to do with it, but I still don't know a single person who drives 55 and gets 19 and up mpg with a 3/4 ton truck, and don't know anyone who brags about mileage in the half ton except for Moparts...

My 2021 6.4 2021 averages a bit over 16 overall, and typically shows 19 to as much as 21 driving highway. This is on the average fuel economy reading on the dash. Doing some quick math at the pump I find that the readout on the dash averages somewhere between 1/2 mpg to 1 mpg too optimistic.
I'm finding as I am getting older and more burnt out I have no bandwith to drive very aggressively, I get to where I am going at approximately the same time without mashing the throttle all the time, or racing to the next red light whipping around people then smoking the brakes so I can be first at the light when it turns green like so many knuckleheads seem devoted to doing.
On the highway I usually find myself doing 70-72 mph. This readout was when I got home after a trip to Indiana a few months ago. I topped off about 80 miles from the Illinois border and I drove highway until I dropped a friend off and then drove the last 25 miles home on side roads with some traffic lights but light late evening traffic. It had been a long day and for the last leg of that trip, I just wanted to get settled in one lane and not get too caught up in passing and merging fighting Chicago area traffic, so was doing around 65 instead of my usual 70-75. This picture was from the next morning when I first started it up.
My first truck in the early 80s was a '79 Bronco 351M 2 barrel that got 8-9 mpg and hardly had enough power to get out of its own way sometimes. My next truck was a standard cab '95 Ram 1500 5.9 that averaged 13-14 overall, and maybe 17+ highway, and would run circles around my old Bronco.
Now I have the new 3/4 ton which is big enough I could almost park the Bronco in the bed, handily outperforms the 1500 and gets better mpg to boot. As an engineer I am very impressed with the remarkable improvements in engine and driveline performance over the last 40 years!!
Shame that the powers to be seem bent on tossing away all this progress and amazing technology chasing very over optimistic EV dreams.

What was the OP asking about?

Oh yeah, gas mileage on half ton trucks. But maybe someone also wanted to know about mileage on the heavier trucks.

And you think that actually answering the question that was asked is bragging?

My 6.4 2011 2500 with a 6.4 BGE short block and 5.7 top end and cam will get 19 MPG on the highway unloaded at about 65, never been able to hit an honest 20 even driving much slower. Starts to drop off pretty quick if loaded or driving faster. It easily does better than my 2013 2500 with a stock 5.7 and is pretty much dead even with my 2009 and 2012 1500s with stock 5.7s. The worst MPG I ever got with the 6.4 truck was towing the 2013 truck on an open trailer 75-80 mph in some hilly territory, it dropped down to 12.5 MPG. I do try to always run premium when towing as it has a lot of compression with the 5.7 heads on it.