New Jeep 2.0T Hurricane 4 has complex tech [Engineering Explained]

[Dusty Dude]

These vehicles are blowing up within the first 200 miles. Quite literally fuel from the dealership purchase. Some were even damaged right off the delivery truck.

Where are the dealerships getting their fuel? I know a lot of dealers in the NW Chicago area were not using top tier fuels if they were filling the tank upon purchase. Regardless, I can’t believe the fuel map was programmed so poorly as to not take garbage fuel into account.

Sponsored

 

[2nd 392]

Where are the dealerships getting their fuel? I know a lot of dealers in the NW Chicago area were not using top tier fuels if they were filling the tank upon purchase. Regardless, I can’t believe the fuel map was programmed so poorly as to not take garbage fuel into account.

FWIW, dealer filled with top tier premium on the test drive at purchase. …. Because I was watching ? Dunno, but he used a card at his select station indicating typical.

 

[alphawolff]

Where are the dealerships getting their fuel? I know a lot of dealers in the NW Chicago area were not using top tier fuels if they were filling the tank upon purchase. Regardless, I can’t believe the fuel map was programmed so poorly as to not take garbage fuel into account.

Whatever the closest gas station is. For us it's Shell. They will put 87 octane in almost all vehicles at time of sale in most cases, but regardless it shouldn't grenade a modern engine like this. Especially one *designed* for 87.

 

[Matt878]

I do like how many people are freaking out over this yet having 2 plugs a cylinder isnt a new thing. Sure its not common but its not like there isnt a history of it.

my 114 ci Harley Davidson has 2 plugs per cylinder lol

 

[alphawolff]

my 114 ci Harley Davidson has 2 plugs per cylinder lol

Are they different plugs and if you put them in the wrong hole it destroys the engine?

We've had 16 plugs in the hemis for over a decade. The new part is using different style plugs in each hole.

 

[2nd 392]

my 114 ci Harley Davidson has 2 plugs per cylinder lol

And the R-4360 Wasps I worked on designed in 1941, production in 44 had 56 plugs, 2 per on redundant magnetos for 28 cylinders. Aircraft started using them about WW1. Nutin’ new. Oh yeah, 56 same plugs.

 

[Dusty Dude]

Are they different plugs and if you put them in the wrong hole it destroys the engine?

We've had 16 plugs in the hemis for over a decade. The new part is using different style plugs in each hole.

Don’t these plugs have a different function as opposed to working in parallel? Or did I read the description of operation wrong?

 

[alphawolff]

Don’t these plugs have a different function as opposed to working in parallel? Or did I read the description of operation wrong?

The function description of the plugs is rather long. Essentially they fire off at different times depending on load demand. In the hemi they both fired off each cycle for complete ignition

 

[Guv]

Pre chamber and Main chamber.
Pre helps initiate combustion in the main chamber. Probably a high EGR engine.

 

[Heimkehr]

It’s kinda crazy they didn’t learn from the old 2.0T?

Learn what? Per long-term feedback from 2.0T owners, the current Hurricane 4 runs acceptably well on 87 octane; the PCM just pulls a bit of timing (to no apparent ill effect) based on the grade of fuel that it perceives is being used. 91 is recommended for certain use cases -- e.g., towing -- but it isn't otherwise compulsory.

It is surprising that 90+ isn't specified for the new GMET-4 Evo engine, but that's due solely to the sheer degree of its engineering when contrasted with the comparatively simpler 2.0T that's currently paired with the Wrangler.

 

[croppz]

Learn what? Per long-term feedback from 2.0T owners, the current Hurricane 4 runs acceptably well on 87 octane; the PCM just pulls a bit of timing (to no apparent ill effect) based on the grade of fuel that it perceives is being used. 91 is recommended for certain use cases -- e.g., towing -- but it isn't otherwise compulsory.

It is surprising that 90+ isn't specified for the new GMET-4 Evo engine, but that's due solely to the sheer degree of its engineering when contrasted with the comparatively simpler 2.0T that's currently paired with the Wrangler.

Never said I was against using 87 but I’m also not for it. I’ve used it in a pinch on the jeep and the world didn’t explode.

HOWEVER, Pulling 10 degrees of timing on 87 like the current 2.0t does may be acceptable for you. But in the dead heat of summer, with how hot these engines already run. I’m good on taking that risk. Turbo charged engines need and prefer more octane, it’s pretty much car 101. Turbo+heat+87=knock and pulled timing, no matter what the platform is.

 

[alphawolff]

Just to clear the air up - currently the engine is knocking to such an extreme on 87 octane that the plugs are being destroyed. If the plug falls apart you need a new engine, if it's just smashed in you can get away with replacing the plugs. I personally am seeing 2-3 of these a week, not including those other techs at my shop are seeing. The plugs are heavily restricted and we're only able to order one set a week, so the backlog is starting to pile up.

Reminder this is a 13:1 compression 4 banger turbo pushing over 30 pounds of boost hauling around 3 tons. I'm not really sure what the target market was for this engine, but it's definitely not a soccer mom mobile.

Stellantis is currently requiring 91 octane or above in this engine until further notice. If anyone is considering a 2026 GC, I'd strongly suggest avoiding it entirely. Check out the Durango, they're bulletproof.

 

[Ratbert]

Just to clear the air up - currently the engine is knocking to such an extreme on 87 octane that the plugs are being destroyed. If the plug falls apart you need a new engine, if it's just smashed in you can get away with replacing the plugs. I personally am seeing 2-3 of these a week, not including those other techs at my shop are seeing. The plugs are heavily restricted and we're only able to order one set a week, so the backlog is starting to pile up.

Reminder this is a 13:1 compression 4 banger turbo pushing over 30 pounds of boost hauling around 3 tons. I'm not really sure what the target market was for this engine, but it's definitely not a soccer mom mobile.

Stellantis is currently requiring 91 octane or above in this engine until further notice. If anyone is considering a 2026 GC, I'd strongly suggest avoiding it entirely. Check out the Durango, they're bulletproof.

It can't retard the ignition sufficiently? I wonder how quickly 85 octane mountain gas destroys it.

 

[tk1700]

It can't retard the ignition sufficiently? I wonder how quickly 85 octane mountain gas destroys it.

I would think the same as 87 at lower elevation.

 

[alphawolff]

It can't retard the ignition sufficiently? I wonder how quickly 85 octane mountain gas destroys it.

My guess is it's such a high compression engine making so much boost it happens so quickly the engine can't really respond in time. I suspect the management thresholds will change to prevent the knock scenario before it happens rather than responding to it like normal.

Normally knock starts to occur and the PCM hears it and starts to retard well before the operator notices it. If the starting to occur part is already enough to cause damage then there's not much the PCM can do. It's very possible it's just an error in the PCM tuning rather than engine design/octane limitations.

Sponsored