3.6L Pentastar V6 24V VVT Upgraded Engine vs. Current JK Engine

[nowandthen]

I see "upgraded engine" in various threads, but don't see any specifics. Does someone know how this new 3.6L Pentastar V6 24V VVT Upgraded Engine compares to the current V6? Does it have more horse power.? Does it have more torque? Is it more fuel efficient? I understand it has been "strengthened" for ESS, is ESS the extent of the upgrades to this "upgraded engine"?

Sponsored

 

[RobNY]

The new updated "PSU" Pentastar has already been implemented in the Grand Cherokee and has these new upgrades:

• 15% higher torque below 3k RPM
• >6% better gas mileage
• +5hp on Grand Cherokee
• 2-speed variable valve lift (one speed for better fuel economy and another for preserving power)
• Torque driven cam phasing valve timing system (cuts oil demand and reduces knock during hot starts, also works better with ESS).
• New fuel injectors allow for better atomization
• Internal friction reduced by using HG-R1 on the timing drive guide-faces, low-tension piston rings, new valve springs, carbon coated piston pins
• Lightest Pentastar ever (326 lbs)

 

[nowandthen]

The new updated "PSU" Pentastar has already been implemented in the Grand Cherokee and has these new upgrades:

• 15% higher torque below 3k RPM
• >6% better gas mileage
• +5hp on Grand Cherokee
• 2-speed variable valve lift (one speed for better fuel economy and another for preserving power)
• Torque driven cam phasing valve timing system (cuts oil demand and reduces knock during hot starts, also works better with ESS).
• New fuel injectors allow for better atomization
• Internal friction reduced by using HG-R1 on the timing drive guide-faces, low-tension piston rings, new valve springs, carbon coated piston pins
• Lightest Pentastar ever (326 lbs)

Thanks Rob! More torque at lower RPMs is good to hear. So many specs list torque and HP ratings at crazy high RPMS.

 

[The Great Grape Ape]

Thanks Rob! More torque at lower RPMs is important!. So many specs list torque and HP ratings at crazy high RPMS.

Yes, but people need to know that peak torque and peak HP don't mean as much as knowing how that torque is delivered. A lot of people moan about the Pentastar delivering max torque at 4400 RPM, but don't realize it delivers 96% of it's torque below 2,000 RPM, so does it really matter that you can get another 10lbft by waiting another 2400RPM?
The max number matters less than when/how it's delivered. The current Wrangler Pentastar is a very flat torque curve and gets up to power rather quickly and stay there throughout most of the range. Some other vehicle are slow to get to even 75% of their power by that same time and as slow to get to the next 25% , but then drop off dramatically after max torque is reached. A nice early flat curve is good for what the Wrangler does so this update is very welcome.

Now the same max @ 4K+ RPM is likely with the new Pentastar, but the new 95 percentile might occur near 1,500 instead of 1,800 meaning better early on throttle response to help move the intertia of big tyres, especially over obstacles.

Also remember that the torque-converter plays a big role in how that power is delivered too and it's lock-up point is currently @ 1,500 RPM on the NAG1 so anythig below that is somewhat mitigated anyways, and I haven't seen a number for the lock-up point on the new 2nd gen 8HP50 yet, but the 45 was earlier.

The other thing to understand is the possibility that the Pentastar update to the Wrangler might be slightly different than the Grand Cherokee so you might see raw numbers go in different ways (no I'm not talking the delayed DI update).
The tune of the RAM and the Grand Cherokee both have different power numbers than the Wrangler; and while it's unlikely to happen, I would love to see the new Wrangler engine get more of a kick in torque than HP, as unlike the GC the Wrangler needs the torque more than the HP, so a 10lbft boost to torque like the RAM (but without the 20HP boost) would be very welcome, as that's where it would do the most good.

 

[BillyHW]

Yes, but people need to know that peak torque and peak HP don't mean as much as knowing how that torque is delivered. A lot of people moan about the Pentastar delivering max torque at 4400 RPM, but don't realize it delivers 96% of it's torque below 2,000 RPM, so does it really matter that you can get another 10lbft by waiting another 2400RPM?
The max number matters less than when/how it's delivered. The current Wrangler Pentastar is a very flat torque curve and gets up to power rather quickly and stay there throughout most of the range. Some other vehicle are slow to get to even 75% of their power by that same time and as slow to get to the next 25% , but then drop off dramatically after max torque is reached. A nice early flat curve is good for what the Wrangler does so this update is very welcome.

Now the same max @ 4K+ RPM is likely with the new Pentastar, but the new 95 percentile might occur near 1,500 instead of 1,800 meaning better early on throttle response to help move the intertia of big tyres, especially over obstacles.

Also remember that the torque-converter plays a big role in how that power is delivered too and it's lock-up point is currently @ 1,500 RPM on the NAG1 so anythig below that is somewhat mitigated anyways, and I haven't seen a number for the lock-up point on the new 2nd gen 8HP50 yet, but the 45 was earlier.

The other thing to understand is the possibility that the Pentastar update to the Wrangler might be slightly different than the Grand Cherokee so you might see raw numbers go in different ways (no I'm not talking the delayed DI update).
The tune of the RAM and the Grand Cherokee both have different power numbers than the Wrangler; and while it's unlikely to happen, I would love to see the new Wrangler engine get more of a kick in torque than HP, as unlike the GC the Wrangler needs the torque more than the HP, so a 10lbft boost to torque like the RAM (but without the 20HP boost) would be very welcome, as that's where it would do the most good.

How much does the torque converter multiply torque in the low RPM range?

 

[jeepney123]

A great article comparing the 2010 and 2016 Pentastar engine's.

http://australiancar.reviews/2016_Pentastar_V6.php

 

[The Great Grape Ape]

How much does the torque converter multiply torque in the low RPM range?

IIRC the ratio is close to 2:1, but I can't remember the specific number I was given by 2 of the after-market boost comoanies I was asking at the time (one turbo , one SC for my old Rubi).

 

[Wolfslash16]

Everything about it sounds great, until the piston rings. I've of people having oil blow by and consumption issues with those...

 

[BillyHW]

IIRC the ratio is close to 2:1, but I can't remember the specific number I was given by 2 of the after-market boost comoanies I was asking at the time (one turbo , one SC for my old Rubi).

You're a veritable fount of knowledge, Great Grape Ape.

 

[BlackPot]

Hi, will the new pentastar be ethanol compliant? Here the ethanol is 0.59€/L and standard gasoline 1.4€/L so it is important
regardless of fuel consumption.

 

[BillyHW]

Hi, will the new pentastar be ethanol compliant? Here the ethanol is 0.59€/L and standard gasoline 1.4€/L so it is important
regardless of fuel consumption.

I think it can do up to E85, but the Great Grape Ape will confirm I'm sure.

 

[WXman]

Yes, the Pentastar makes torque early and flat. But, so did the 4.0. And so did the 3.8. And all three of those engines, covering the 1980s to now, were in the 230-260 lbs/ft range. It's pathetic.

To me, what matters more is the AMOUNT of torque being made. And the Pentastar sucks. 260 lbs/ft?? In 2017?? C'mon man. 25 years ago V6 engines were making close to that.

In my opinion, the biggest improvement Jeep could make is to find a way to get torque numbers up substantially. The diesel engine is going to feel night and day different. The EcoDiesel is a torque monster, the Pentastar is a horsepower warrior. Totally apples to oranges. Torque is what improves MPGs, towing capacity, offroad finesse, etc. Not horsepower.

 

[The Great Grape Ape]

Hi, will the new pentastar be ethanol compliant? Here the ethanol is 0.59€/L and standard gasoline 1.4€/L so it is important
regardless of fuel consumption.

It appears they dropped E85 support with the latest update, it currently is only listed as supporting E15.

 

[The Great Grape Ape]

To me, what matters more is the AMOUNT of torque being made. And the Pentastar sucks. 260 lbs/ft?? In 2017?? C'mon man. 25 years ago V6 engines were making close to that.

C'mon man, get real.
10 years ago the Ford 4L V6 in the Exploder and Mustang was making 250lbft with 400CC more, the Cadillac 3.6L V6 was 252lbft, and even today that GM engine in the Canyon/Colorado with all its tweaks direct injection, and unpdated intake/exhaust is only matching the torque p & HP of the old Pentastar in the RAM.

To which even Even the engines that currently provide a small bit more torque, all do so with higher octane requirements even if they aren't the ones with direct injection, and have more pedestrian numbers when tested with 87 regular.
The only reason the 4L FJ cruiser had more torque (and still 60HP less) was the premium 91 fuel, under regular fuel it's torque number dropped to 248lbft.

The EcoDiesel is a torque monster, the Pentastar is a horsepower warrior. Totally apples to oranges. Torque is what improves MPGs

Torque isn't what provides the diesel with it's MPG, it's the 15% already built into the fuel, plus a smaller displacement engine that can exist without boost much of the time.

 

[WXman]

C'mon man, get real.
10 years ago the Ford 4L V6 in the Exploder and Mustang was making 250lbft with 400CC more, the Cadillac 3.6L V6 was 252lbft, and even today that GM engine in the Canyon/Colorado with all its tweaks direct injection, and unpdated intake/exhaust is only matching the torque p & HP of the old Pentastar in the RAM.

To which even Even the engines that currently provide a small bit more torque, all do so with higher octane requirements even if they aren't the ones with direct injection, and have more pedestrian numbers when tested with 87 regular.
The only reason the 4L FJ cruiser had more torque (and still 60HP less) was the premium 91 fuel, under regular fuel it's torque number dropped to 248lbft.



Torque isn't what provides the diesel with it's MPG, it's the 15% already built into the fuel, plus a smaller displacement engine that can exist without boost much of the time.

I suppose we can disagree on this one. Having your peak torque directly in the middle of your cruising range is what allows MPG numbers to rise substantially. Every time one of these weak gas engines has to downshift the fuel pulse rate goes up rapidly.

As far as driving performance goes, there's a reason why the Camaro SS smacks the Mustang GT around, even though they are now within 5 horsepower of each other, and that's because the Camaro is loaded with torque.

What we're seeing now days is a shift away from "truck engines" that made low HP but high torque to "car engines" that are the opposite, and manufacturers are using these car engines across their entire lineups.

The Pentastar works OK in the base model Challenger, but it is dreadful in the Wrangler, particularly while trying to turn large tires or pull a fishing boat.

Sponsored