Pentastar vs Hemi, which should you choose?

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Huliodude

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When I was in the market for a 4th Gen Ram 1500 Classic, I was pretty torn about whether to go with the Pentastar V6, or the Hemi.

It can be difficult to make the right decision with just a short test drive from the dealer. Now that I’ve owned both, I wanted to give a detailed account of the differences, and things to watch out for. Yes, the topic has been beat to death but I think there’s quite a bit of generalization and points not mentioned.

Bear in mind, this perspective comes from someone who could easily do without a truck, I don’t tow, don’t need to haul, but the idea of driving a pickup truck was in the back of my mind for many years. I had owned mostly sporty cars, some of my favourites being a fox body Mustang 5.0 LX trunk with a manual, a c4 Corvette, an e90 328i, e92 335i, and an f30 335i. The biggest reason I looked at RAMs was because of the ZF 8 speed. It was awesome in the f30. I’ve never felt an auto transmission work so well before.

The very first truck I ever owned ended up being a 2019 Ram 1500 Classic Crew Cab 4x4 with a 3.55 gear and 20” wheels. I put on 67,000km on it, or 41,631miles. I loved this truck! Fantastic on gas, quiet, smooth, cavernous space inside, great visibility on the road. Finally I could stop paying for premium gas, and run plain old regular.

It’s funny how once you own a truck, a million reasons come up for owning one. It just made life so much easier. Carrying house materials, dirt bikes, bicycles, Christmas trees, snow blowers, dishwashers, firewood, furniture, all sorts of stuff I could have never done with a car.

Ok, the good about the V6 RAM.

It’s fantastic on gas for how big and heavy this truck is.
The 3.55 gear ratio allows it to get out of its own way.
The Pentastar is very quiet and very smooth.
It’s easy to change the oil, and doesn’t require any special oil type.
This drivetrain is very car like. It shifts smooth, the engine is quiet, idles super smooth, very low NVH. I can’t say enough good things about this engine.
If you rev it out, it’s surprisingly powerful.
The transmission is quick to downshift giving your the revs you need to accelerate.

The bad about the V6 RAM.

It’s very low on torque for a truck this heavy, especially below 3000rpm. If you want power, you need to rev it and put your foot in it.
I test drove it with the 3.21 gear, and I honestly wouldn’t recommend it. The 3.55 should be the longest gear RAM offers, and leave the 3.21 option for the Hemi.
Even with the 3.55 gear, the motor cannot hold 8th gear on even the slightest of inclines on the highway. It downshifts a lot, simply because the motor lacks torque at lower RPM’s.
When you rev it beyond 3500rpm, it doesn’t sound great. It sounds like you’re pushing it hard, and it’s not particularly enjoyable.

I now own the exact same truck except it’s a 2021 classic, with a Hemi and 3.21gear and ZF 8speed. I’ve only put about 3,000km on it, but I’ve got a pretty good feel on most aspects of this setup.

The good about a Hemi powered RAM.

Wow, the difference in power is nothing short of shocking, even though I went down to a 3.21 gear. If you look at a HP/torque dyno chart of a stock 5.7 Hemi, you’ll see this motor makes far more torque at even 1200rpm than the Pentastar can make at any RPM!
The grunt this burly V8 provides makes it feel like a different truck, and you end up driving it different. For example, on ramps to the highway are now fun. Getting up to speed and well beyond are no issue. Is your lane ending? In a V6 you need to brake and go behind whoever is next to you. In the Hemi, you can be a hooligan, step on it and blow the doors off the guy next to you.
This motor does everything effortlessly, while the V6 works hard in this truck.
You can go about your day taking it easy, and the engine will never go over 2000rpm. And it takes a lot more than a small incline to get this motor to require a downshift. It rarely needs to downshift, and the transmission generally shifts much less often.
Even if you tow or haul nothing, you will definitely use the power this engine offers just in regular driving situations. The fact that it tows more is just a bonus.
It gets surprisingly good highway mileage.
It has very good engine braking.
This engine sounds great, is happy to rev if you want it to, and it never sounds strained. It’s a testament how good the old school pushrod V8 design is. It still competes with much more modern engines.

The bad about the Hemi powered RAM.

It’s definitely thirstier, by about 10% from what I can tell. It’s particularly worse in the city, and just idling it a red light seems to consume more fuel than the v6.
Because the engine is a lot heavier, you feel it in the truck. The truck is less nimble, especially noticeable on more spirited right hand turns.
I understand oil changes are not easy or as clean as the V6. Not looking forward to that.
MDS…. While it saves gas and that’s great, you definitely feel it when it’s active. It’s vibrates a fair amount and the V6 is much smoother when cruising for this reason. I don’t dislike it enough to disable it since I enjoy the fuel savings, but I’m surprised the price you pay in NVH.

Other differences I noticed.

The V6 exhaust has a drone when it’s below 0c outside.
The V8 dual exhaust is louder than the V6, but not annoyingly so. If you want the quietest truck overall, the V6 is your choice.
The V8 is slower to get into gear when you put it in D. It’s slower than I’d like.
The V6 doesn’t have much engine braking. You’d think the lighter truck would be easier on the brakes, but it’s definitely the opposite, the V8 is easier on the brakes.
When MDS deactivates on the Hemi, the torque converter briefly unlocks to smooth out the transition to 8 cylinders. This is noticeable, and another reason why I don’t like MDS too much. It makes for a busier drivetrain.
The V6 engine takes longer to warm up than the V8. However, the V6 has a transmission warmer as well as a cooler, and in cold Canadian climates, the trans warmer is welcome. The V8 only has a trans cooler, and takes about 4 times as long to warm up. The V6 trans can be at full operating temperature in 15mins, and the V8 can take upwards of an hour in cold climates. That can’t be good for fuel economy, and the Hemi can use all the help it can get.
The V6 cabin heater is just adequate, the V8 will melt the skin off your face. Crazy hot.
No idea if the V6 vs V8 air conditioning is any different, perhaps someone can chime in on that.
The V6 makes the truck feel more “car like”, the V8 feels more like you’re driving a truck, whatever that means to you.
The V8 front end dives more on braking, probably due to the extra weight up front.

My overall opinion

While I don’t need to tow or haul, I still prefer the Hemi. The extra fuel consumption is worth it. To put the 10% difference in fuel costs into perspective: I spent about $3k in gas last year with the V6, and with the Hemi I’ll spend $3300, all things being equal. The V6 burns 90% of the gas the Hemi does. But it only gives you 77% of the horsepower, and only 66% of the torque. This shows just how efficient the Hemi really is. Now I realize peak output is rarely used, but it’s the extra power everywhere across the RPM range that really changes the the driving experience.

In all fairness, if you own a V6 with a 3.55 gear, I do believe it’s also a fantastic choice, albeit less fun and capable in most ways than the V8.

If you have a V6 with the 3.21, well…. You’re a better man than I.
 

ramffml

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Nice write up! One thing I will add, with the ZF 8 speed I no longer care about downshifts on hills, which happen even with the 3.21/hemi every once in a while if the hill is large enough and the speed fast enough. The shift only raises your RPMs by about 400, and it's smooth and seemless. On the same roads with one of my old cars the shift was much firmer and you felt the tug, heard the revs, and felt the difference in power all at the same time, so noticing that was a subconcious reminder everytime that the car was not powerful.

But with the hemi anyway, I don't notice anything really. The engine just makes a somewhat higher noise and that's that. No fuss, no drama, no tiring noise, no jerking. So I no longer worry or care about downshifts on the highway. This transmission also runs pretty cold so no worries about heat or burning it out either.
 
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Huliodude

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Nice write up! One thing I will add, with the ZF 8 speed I no longer care about downshifts on hills, which happen even with the 3.21/hemi every once in a while if the hill is large enough and the speed fast enough. The shift only raises your RPMs by about 400, and it's smooth and seemless. On the same roads with one of my old cars the shift was much firmer and you felt the tug, heard the revs, and felt the difference in power all at the same time, so noticing that was a subconcious reminder everytime that the car was not powerful.

But with the hemi anyway, I don't notice anything really. The engine just makes a somewhat higher noise and that's that. No fuss, no drama, no tiring noise, no jerking. So I no longer worry or care about downshifts on the highway. This transmission also runs pretty cold so no worries about heat or burning it out either.

You're right, having 8 speeds makes the gear ratio spread much closer, so the drop in RPM at most is about 25%, making it less noticeable. I hear the Ford/GM 10 speeds have only a 20% drop in RPM, making the far more frequent shifts less noticeable yet. I'm not sure if adding gears to a transmission is a case of diminishing returns, but that's another discussion.

However, the V6 downshifts far more often, and on steeper hills it's not uncommon to see it downshift 2 or even 3 gears to get the RPM where needed to maintain speed. The transmission handles the job marvellously, but it makes for a lot of shifting and gives you the impression the motor is undersized for the weight of the truck. JMHO.
 

zogg

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I had a grand Cherokee with the v6 and found it very adequate until I test drove the same suv with a Hemi. Wow!!

When I traded for my ram I turned down a couple of trucks just because they had the v6. I wanted the hemi in a full size truck

My son-in-law has a Ram with the v6 and he never hauls anything but his kids, but he complains about it all the time. He wants a new truck with a v8 but my daughter won’t let him…haha
 

rule18

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Good writeup, tons of members share your opinions/experience. The one thing I'll throw in to the Pentastar mix is a 3.92 rear (which I have), it makes a significant difference. My past two RAMs had the Hemi, but once I stopped towing regularly I decided to try the 3.6, in large part because I liked it in my 2012 Wrangler. The 3.92 rear was a rarely found option in 2017 outside of the Rebel trim level, but I'm sure glad I got one!
 

Dean2

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Bought the 5.7 in a Grande Cherokee Summit after test driving both. My buddy bought the exact same model but with the 6 because he wanted better mileage.The Hemi has WAY better highway power, is smooth and quieter. Final bonus, in 14,000 miles my overall average is 2 MPG better than his and on Highway or city use I get better gas mileage than him. (All hand calculated) I know it is a sample of 1 but even if the Hemi average 2 mpg less, I would consider it a more than fair trade off. When I bought the new pickup, 6.4 Hemi all the way.
 

zogg

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I bought a 2007 Silverado 3/4 ton with a 6.0 v8. It ran great and towed well buy got 10 mpg empty and 5-6 towing. At that time gas was over $4.00/gallon so a fillup was $100.00!!

My Hemi get 20-21 mpg hiway and 16-18 city. I’m very happy. I would never trade the hemi for the v6 to get 2 more mpg. There are just too many drawbacks to the v6 for me.
 

turkeybird56

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If I JUST drove to town and back, V6 all day. But if I take ne trips, push a lil hard, tow, than the Hemi all the way. Personally, just ME, HEMI. I have no use for a 6 cylinder mode in a truck now, and I had an ED. The ED was great for towing up to moderate, but could not get out of it's own way. SO overall, HEMI just the best option. Back in the day, for a while, I did have an older F 150 with the Straight 6 and 4 speed. That truck moved if U knew how to drive a stick, but that is a different era. Since I due travel in-frequently, but do have a big trailer and a Hossie and need hay and such, only the HEMI works for me, just wish I had 3:92 instead of 3:21 rear end.
 

zogg

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If I JUST drove to town and back, V6 all day. But if I take ne trips, push a lil hard, tow, than the Hemi all the way. Personally, just ME, HEMI. I have no use for a 6 cylinder mode in a truck now, and I had an ED. The ED was great for towing up to moderate, but could not get out of it's own way. SO overall, HEMI just the best option. Back in the day, for a while, I did have an older F 150 with the Straight 6 and 4 speed. That truck moved if U knew how to drive a stick, but that is a different era. Since I due travel in-frequently, but do have a big trailer and a Hossie and need hay and such, only the HEMI works for me, just wish I had 3:92 instead of 3:21 rear end.
Agreed. My 2019 classic came with the 3.21…I bought it used. I had a 2015 with the 3.92 gears and the mpg was close to the same and it drive better overall. Next truck will definitely have the 3.92.
 

turkeybird56

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Agreed. My 2019 classic came with the 3.21…I bought it used. I had a 2015 with the 3.92 gears and the mpg was close to the same and it drive better overall. Next truck will definitely have the 3.92.
I honestly neva paid a lot of attention to the rear end. I will next time.
 

retired

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I have owned 4 3.6's 2013, 2014, 2016 and 2018. both 2013 and 2014 had oil cooler housing issues. the oil filter cooling housing issue is widely known. the 13 and 14 ended up with the cylinder head issues which is also a known issue but those issues both happened after I had gotten rid of them. I only knew because I received letters from FCA notifying me if I had not had warranty I would have had to pay for the fix..they were selling maxcare warranties. Mine were in fairly built up jeeps rubicons with 4.10's I really can't imagine myself being happy with a 3.6 in a full size pickup. we all are different tho when it comes to what makes us happy.
 

DILLIGAF

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the 3.6L is a minivan engine that ****** oil everywhere.
 

Jeepwalker

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Thanks for the real-world owner perspective! Very interesting.

I have a Jeep GC with the V8 and it moves about and passes cars effortlessly. My daughter learned to drive in that vehicle. When she would go with the driving instructor in their minivan (with 3 people inside), she told him she thought there was something wrong because it couldn't go uphill very well ...he he.
 

Dr. Righteous

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I bought my Hemi 14 RAM mainly because I had trailer towing duties in mind. It does great on that.
But my Dad's 18 Bighorn RAM with the v6 and 8spd auto is smooth like butter. If it was not for the trailer duties I would go with the V6 in a minute.
The most common failure on the 3.6L Pentastar is the STUPID plastic oil filter/cooler assembly. It eventually cracks and leaks. Dorman has an all aluminum replacement kit that comes will all gaskets needed for the change over. Fix it once, fix it right.
Check with Rock Auto for the best price.
 

turkeybird56

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I bought my Hemi 14 RAM mainly because I had trailer towing duties in mind. It does great on that.
But my Dad's 18 Bighorn RAM with the v6 and 8spd auto is smooth like butter. If it was not for the trailer duties I would go with the V6 in a minute.
The most common failure on the 3.6L Pentastar is the STUPID plastic oil filter/cooler assembly. It eventually cracks and leaks. Dorman has an all aluminum replacement kit that comes will all gaskets needed for the change over. Fix it once, fix it right.
Check with Rock Auto for the best price.
^^^ DITTO ^^^ on the plastic to aluminum transfer. Will stop eventual oil change/leak issues by the filter, an Excellent upgrade.

ADDED: I just hate the oil bath on my 5.7L filter. If I was driving and changing a lot, I would do a Filter relocation. The only filter I have seen worse than the friggin Hemi, was on a 2010 Ford F150 with the 5.4 Triton. Unless U had a commercial ramp and able to turn wheels, not on ground or ramps, U were guaranteed an Oil Shampoo, just saying.
 

Docwagon1776

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Hemi/3.92s.

I was mildly interested in the newly updated Grand Cherokee, but since they restrict the hemi to the Trailhawk (which I don't want, no air suspension thank you) or higher trims I'm no longer even mildly interested. Too slow to be interesting in a vehicle with that much weight to move around.
 
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Huliodude

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In all fairness, I do believe the Pentastar V6 has got to be the best overall naturally aspirated mass-produced V6 out there. It does make good power for its size, is quiet and smooth, reliable, and cheap to fix and maintain. I've owned a couple of Nissan's VQ engines, Honda J series V6 (has a timing belt), Toyotas 1MZ-FE V6 (also has a timing belt), and the Pentastar is better, IMO.
 

joesstripclub

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The only correction I would make is that the Hemis definitely have a transmission heater in addition to cooler. See very long threads on forum members removing or bypassing the heaters.

I haven't driven anything with a pentastar but I've heard good things about it. I was looking at a Tacoma before I bought my Ram but decided a V8 truck would leave me better prepared if I ever wanted to tow anything. I rented a new Tacoma in Denver after buying my truck and the transmission would downshift anytime you even touched the throttle on the highway. There was so much power loss at altitude that it was a total **** and made me feel like the transmission was really doing more work than it should.
 

HEMIMANN

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@rule18 has it right - since you're deadheading, go with V6 and tall axle gear ratio. Excellent combination.
 
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