Premium Fuel

[Rick4570]

The last three tanks of gas, I decided to try premium fuel. I know it is not required, and shouldn't really make a difference. With that said, I found that I stopped hearing the slight engine rattle in hot weather going up hills. Also it felt like it had a bit more power. I live in the Appalachian Mountains, where steep hills are the norm. Definitely felt smoother going up hills. I will go back to regular when the weather starts to cool off. Anyone else notice this?

Sponsored

 

[Stetson]

When I had my 3.6 it would periodically get a tank of premium…more by accident than on purpose. I don’t recall ever noticing a difference.

I also would have the doors Off or the radio blasting or whatever and I was happy to have it motor along

Stetson

 

[Grayhound]

From what I understand the octane will dictate the temperature of detonation of fuel. So it would make sense that premium on hot weather is detonating at the correct time instead of a little early with lower octane.

 

[whitechocolate]

The last three tanks of gas, I decided to try premium fuel. I know it is not required, and shouldn't really make a difference. With that said, I found that I stopped hearing the slight engine rattle in hot weather going up hills. Also it felt like it had a bit more power. I live in the Appalachian Mountains, where steep hills are the norm. Definitely felt smoother going up hills. I will go back to regular when the weather starts to cool off. Anyone else notice this?

Yes, it's less sewing machine like on cold starts. The ECU sorted itself out after a few tanks of 91. Started using top tier gas like Exon, Shell the top tier have better detergents for port injection engines.

 

[AFD]

I switched from 87 Top Tier to 89 Top Tier and have been sticking with that for a few months. Haven't really noticed any significant increase in performance on the steep hills around here and the engine doesn't really sound any quieter. Did notice a slight improvement in fuel economy that coincided with the change, but that could be due to several other factors.

Decided to up the octane based on seeing two recommendations here. One from a dealer technician (LINK) and another from a well-known tuner (LINK). Both were recommending higher octane for the factory tune and due to the increased compression ratio of the newer Pentastars.

Might be a waste of money, but I'll probably up it again to 91 Top Tier if the gas prices settle back down again in the future. Or, if the prices go up again, I might just switch back to 87 to check for any placebo effect.

I usually waste $5 a week on far dumber shit (15k-mile national annual average / 20MPG = 750GAL x $0.30 price increase from 87 to 89 / 52 weeks = $4.33/wk) ?‍

 

[Ang1Sgt]

I’ve been running 91 octane for about 6 months. Now this was a used 2020 when I got it last year with only 4300 miles. It did okay, but seemed to be sluggish for a bit. Now with 10,000 miles on it, she seems to be more eager to please me and with the 91 octane seems to run out better along with consistent fuel economy.

My Jeep is the THIRD vehicle in the family fleet and we bought it to replace a 2013 JK that the wife and I both loved. So for me, this is my “CORVETTE”. I can’t afford a Vette, but this Jeep for me just brings me full circle from my first Jeep CJ back in 1975. So I treat this vehicle to the best things I can afford, like the fuel, the oil changes, and part that goes on or gets replaced. It gets the best I can afford, pure and simple!

 

[Kracka]

My wife switched to 88-octane vs. regular 87 and it's made an improvement in this brutal Texas heat. The Pentastar V6 runs noticably rougher on the cheap discount brands too (such as Kroger).

We've tested this in our 2019 Cherokee Trailhawk 3.2L and 2023 Rubicon 3.6L eTorque and found similar results on both.

 

[Valpo Jeep]

We feed the JLU with 87 octane and all is fine. I don’t even feed the Audi with premium 91 octane, been running 89 octane mid grade in that for almost 90,000 miles now. Audi recommends but does not require 91 octane. At most I am down by less than 5 HP running 89, probably more like only 2 or 3 HP

 

[Bill_BCNtoNY]

I've opted to spend on premium gas since I got this Jeep, the same way I've been looking at the most recommended fluids and any maintenance items.

I'm definitely overspending, but the Jeep world is a hobby (for now, I'm working on developing it into a career of sorts - no idea how yet) and I like to do things as "right" as possible when I can afford it

 

[Ghettomedic]

Hi guys I am new to this forum. I got a high tide 3.6 in May of this year. So far I have 2800 miles. So until about a week ago I was using regular fuel. At some point I started hearing noise like a clatter some call it engine knock. It is only happening during light acceleration just to maintain speed at around 30-40 mph and around 4/5th gears. Found the noise more pronounced going up the hill. So I said what the hell let me try premium fuel 93. And it’s been about a week and it’s far far less noise. If I do hear it the duration is much shorter may be a second or two. So that was definitely improvement. The second thing I noticed was more linear acceleration. Most will say it doesn’t require premium and it’s a waste of money. I get that this was just my experiment. This is my first jeep so I have nothing to compare to so no bias here.

 

[Jeffy56]

The Top Tier (high detergent) fuel is recommended in the owner's manual. Page 506. Help keep the whole fuel and intake system cleaner, especially for DI engines.

 

[4a4c55]

From what I understand the octane will dictate the temperature of detonation of fuel. So it would make sense that premium on hot weather is detonating at the correct time instead of a little early with lower octane.

Not exactly. Octane measures the pressure at which fuel will auto ignite. Of course, temperature and pressure are related, but the testing of octane involves pressure and not temperature. The main purpose of high octane fuels is in high-compression engines, where knocking is more likely because of the high compression. The 3.6 Pentastar has a compression ratio of 11.3-to-1, which isn't high by modern standards.

Different octane ratings are formed with different hydrocarbon mixtures. Eeach component of the blend has a different initial boiling point temperature, so the resulting mixture is influenced by the way those components are distilled and blended at the refinery. You can check out data sheets for high-quality fuel to see examples.

 

[RTinTenn]

I switched to the highest octane available and it has made a big difference. I have the 2022 3.6 e-torque. Sounded like a diesel on regular 87 gas.

 

[ConqSoft]

The last three tanks of gas, I decided to try premium fuel. I know it is not required, and shouldn't really make a difference. With that said, I found that I stopped hearing the slight engine rattle in hot weather going up hills. Also it felt like it had a bit more power. I live in the Appalachian Mountains, where steep hills are the norm. Definitely felt smoother going up hills. I will go back to regular when the weather starts to cool off. Anyone else notice this?

I started using premium in my v6 after my first tank or two and noticed a difference too. Been using it 34,000+ miles now.

 

[Tortolabob]

I have 2 JLs...a 2019 3.6 2dr and a 2023 JLUR 3.6 e torque and I do a lot of beach driving with both. I run 91 octane top tier when it's warm and when climbing dunes and the higher octane gets rid of the low speed engine knock that both had but particularly the 2019. Winter time with no beach driving back to 87 octane. Works for me.

Sponsored