What octane gas do you guys run

[BLK HOLE]

Whose "rule of thumb"? Yours? What is "patently false" is the idea that a multi billion dollar corporation like FCA is using incompetent engineers that would specify using a lower octane fuel that would cause detonation (pinging) in tens of thousands of engines under their warranty.

PS: Mine doesnt ping at all. They shouldn't because they are computer controlled to modify timing if detonation is sensed. Unless you are lugging the crap out of a manual I don't see how they could ping for more than an instant.

The ol..."its a large company and they...KNOW" argument. Meanwhile 400 TSB's later....

Its a stupid argument. They ping, its well known. I bet yours pings too.

Sponsored

 

[ShadowsPapa]

Well know - right. Why is it that most people here say they don't. Mine does not. And my wife has hearing like a hawk or owl - she can hear things that normally men can't hear. It's interesting because about the same time our cats come to alert for something, she's asking me what's that noise.
I know ping, mine doesn't ping, my wife has had several Grand Cherokees over the years, most recently a 2015, 2018 and now a 2021. No ping. And the diagnostics I've run on our vehicles for kicks and to learn how to use AlfaOBD show nothing at all out of the ordinary.

I think you are hearing things. If so many pinged, why haven't the guys pushing these things to their very limits had ping or detonation damage?

Well known to you.

 

[BLK HOLE]

Well know - right. Why is it that most people here say they don't. Mine does not. And my wife has hearing like a hawk or owl - she can hear things that normally men can't hear. It's interesting because about the same time our cats come to alert for something, she's asking me what's that noise.
I know ping, mine doesn't ping, my wife has had several Grand Cherokees over the years, most recently a 2015, 2018 and now a 2021. No ping. And the diagnostics I've run on our vehicles for kicks and to learn how to use AlfaOBD show nothing at all out of the ordinary.

I think you are hearing things. If so many pinged, why haven't the guys pushing these things to their very limits had ping or detonation damage?

Well known to you.

1. A lot might not.
2. Most people don't know WTF they're listen for. Even when they think they do.

 

[ShadowsPapa]

1. A lot might not.
2. Most people don't know WTF they're listen for. Even when they think they do.

I know exactly what to listen for, when it's most likely to happen and more. I know the exact causes, why there's a sound, the difference between pre-ignition and detonation.
I've built and rebuilt engines - to avoid detonation and to repair damage caused by it.
It's more than "thinking" in my case, it's being trained and decades of experience dealing with it.
I became even more "attuned" to it after buying a low miles car (22,000 original miles) - seeing it didn't have a steady vacuum i the crankcase (it pulsed) and opening up that 22,000 mile engine only to find it was the SECOND time it had been messed up by detonation. I worked with people who made a simple design change to the heads that resolved the issue. Yes, a simple cut made in the head at the right places eliminated detonation for that engine running over 10:1 on 87 octane. That's when I got into further studies beyond what college and factory classes taught and got extremely interested in the causes and simple preventions.
Imagine putting a head in a mill, making a specific shaped cut not very deep into the chamber and getting rid of detonation and being able to run even 10:1 compression ratios.

GM with the LS engine was able to get rid of detonation issues about 25 years ago - MOPAR has't paid attention?

Today it's easy to run 11:1 with no detonation and on normal 87 octane fuel.

 

[BLK HOLE]

I know exactly what to listen for, when it's most likely to happen and more. I know the exact causes, why there's a sound, the difference between pre-ignition and detonation.
I've built and rebuilt engines - to avoid detonation and to repair damage caused by it.
It's more than "thinking" in my case, it's being trained and decades of experience dealing with it.
I became even more "attuned" to it after buying a low miles car (22,000 original miles) - seeing it didn't have a steady vacuum i the crankcase (it pulsed) and opening up that 22,000 mile engine only to find it was the SECOND time it had been messed up by detonation. I worked with people who made a simple design change to the heads that resolved the issue. Yes, a simple cut made in the head at the right places eliminated detonation for that engine running over 10:1 on 87 octane. That's when I got into further studies beyond what college and factory classes taught and got extremely interested in the causes and simple preventions.
Imagine putting a head in a mill, making a specific shaped cut not very deep into the chamber and getting rid of detonation and being able to run even 10:1 compression ratios.

GM with the LS engine was able to get rid of detonation issues about 25 years ago - MOPAR has't paid attention?

Today it's easy to run 11:1 with no detonation and on normal 87 octane fuel.

Ok

 

[Jeeperjamie]

Well know - right. Why is it that most people here say they don't. Mine does not. And my wife has hearing like a hawk or owl - she can hear things that normally men can't hear. It's interesting because about the same time our cats come to alert for something, she's asking me what's that noise.
I know ping, mine doesn't ping, my wife has had several Grand Cherokees over the years, most recently a 2015, 2018 and now a 2021. No ping. And the diagnostics I've run on our vehicles for kicks and to learn how to use AlfaOBD show nothing at all out of the ordinary.

I think you are hearing things. If so many pinged, why haven't the guys pushing these things to their very limits had ping or detonation damage?

Well known to you.

Il

The ol..."its a large company and they...KNOW" argument. Meanwhile 400 TSB's later....

Its a stupid argument. They ping, its well known. I bet yours pings too.

I got no ping in mine and I know what to listen for as well. The reason why you hear about some doing it in this forum is because it's a forum that's made partly for complaining, that's what a good number of people sign up on here to do. The vast majority of gladiator's made have no issues with this. I run 87 octane in mine, get great gas mileage and have zero complaints in how it sounds.

 

[BLK HOLE]

Il


I got no ping in mine and I know what to listen for as well. The reason why you hear about some doing it in this forum is because it's a forum that's made partly for complaining, that's what a good number of people sign up on here to do. The vast majority of gladiator's made have no issues with this. I run 87 octane in mine, get great gas mileage and have zero complaints in how it sounds.

Ok.

 

[duvinclunk]

It always baffled me when people claim and suggest only running premium on vehicles where the manufacturer says it needs only a certainly amount. These are the people designing the motor. These are the people testing the motor. Do they just say 87 because they want to please people to allow some money savings? Now I understand some have some good knowledge as auto technicians but these technicians do not design motors and do not go to the depth that the manufacturer would go to ensure it works on a certain octane. If Jeep told me 91 or above, I would do it. But they say 87. I don't get why one would want more unless there some power that can be had with more octane.

My post isn't meant to be argumentative, ranting, or designed to stir up someone who is passionate about premium. I'm certainly ignorant to most of the finer engine workings but I'm saying it never made sense to me. I'll just do what the designers of the motor said to do.

 

[PhantomChameleon]

I run 87, which is "mid-grade" here in Colorado.

 

[ShadowsPapa]

It always baffled me when people claim and suggest only running premium on vehicles where the manufacturer says it needs only a certainly amount. These are the people designing the motor. These are the people testing the motor. Do they just say 87 because they want to please people to allow some money savings? Now I understand some have some good knowledge as auto technicians but these technicians do not design motors and do not go to the depth that the manufacturer would go to ensure it works on a certain octane. If Jeep told me 91 or above, I would do it. But they say 87. I don't get why one would want more unless there some power that can be had with more octane.

My post isn't meant to be argumentative, ranting, or designed to stir up someone who is passionate about premium. I'm certainly ignorant to most of the finer engine workings but I'm saying it never made sense to me. I'll just do what the designers of the motor said to do.

This design has been around for about 6 years, and the 3.6 overall longer than that.

Agreed, when you visit a shop you find sick vehicles, visit a forum you find few saying "hey, my truck is perfect in every way" - people look for outlets, places to complain or to find help for problems. They rarely gather to praise a vehicle. Unless it's a Jeep, of course.

I run 87, which is "mid-grade" here in Colorado.

While in CO last week, I filled up with 87 - I knew there would be fuel left in the tank when we left and hit lower elevations, otherwise I'd have gone for the cheaper 85 if I had thought I was going through a tank full while there.

 

[BLK HOLE]

The 3.6 compression currently is only a couple years. Older models had less compression.

 

[ShadowsPapa]

2016 saw the compression increase - this is Gen 2 - and the changes took place in 2016.
Gen 1 has 10.2:1

3 distinct sources name the change year as 2016. One is a performance magazine site.

In 2016, FCA updated the 3.6 Pentastar motor for the first time since 2009 to improve power and fuel efficiency across the Chrysler, Jeep and Dodge lineup. This resulted in a 6% gain in fuel economy and a 14.9% gain in torque below 3000 RPM. Enhancements such as two-step variable valve lift (VVL), cooled exhaust-gas recirculation (EGR) and innovative weight-reduction strategies boost the engine’s efficiency and performance, all while preserving its smoothness.
The additional torque on the is due in part to the numerous internal changes that better harness the combustion event. The most notable being the engine’s compression ratio jumps to 11.3:1 from 10.2:1, compared to the previous gen 1 version. Notice in the picture above how the pistons are nearly identical, but the left piston lacks the additional material found on the top side of the right piston. That little bit of extra material is all that is needed for a compression increase.

In 2016, FCA released an upgraded Pentastar engine family and a new version of the 3.6L V6 for the Jeep Grand Cherokee and Dodge Durango. The revised engine now has a two-stage variable valve lift (VVL). The VVL system provides low and high valve lifts. Low-lift settings at low speeds save fuel (up to a 2.7% increase over the previous version), while high valve lift turns on when power is needed. Unfortunately, the manufacturer was forced to install a cooled exhaust gas recirculation (EGR) system. The modified engine also features a new plastic intake manifold with longer runners, increased torque, high-tumble intake ports inside cylinder heads, new valve springs, and low-tension piston rings. The fuel system received new eight-hole injectors. And the good news is, the engine has kept a port fuel injection. The variable valve timing (VVT) system was recalibrated. The compression ratio was increased from 10.2:1 to 11.3:1.

From another sources-
For 2016, FCA released an updated version of the 3.6 L engine for the Jeep Grand Cherokee and Dodge Durango. This engine now featured two-stage variable valve lift (VVL), a cooled EGR, a new intake manifold, new fuel injectors, and new ignition coils. It also features upgrades to the variable valve timing (VVT) system, an increased compression ratio (11.3:1)

 

[BLK HOLE]

Like I said...

 

[ShadowsPapa]

LOL - that's funny. I point out it's been at least 5 or more and you say couple then come back with like I said.
Seems to me 2019 would make it "a couple" of years.
Since 2016 - that's a fair history of successfully running that ratio and design. At least 5 model years. Probably 6 calendar years.

 

[BLK HOLE]

LOL - that's funny. I point out it's been at least 5 or more and you say couple then come back with like I said.
Seems to me 2019 would make it "a couple" of years.
Since 2016 - that's a fair history of successfully running that ratio and design. At least 5 model years. Probably 6 calendar years.

Sorry about the semantics.

Sponsored