Gas in the 2.0T - Is my understanding correct?

[BlackGenesis]

Yes, you lose power with 87, more so at higher temps. Up to 30 hp /10 trq, 2mpg loss is expected during summer.
Engine retards timing due to knock. No octane sensors.
Wasn't 2.0 option cost $2k higher?

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[Whiskey 13]

I have 15K on mine and run 87 most of the time, If I know I am going to be towing over any distance I will burn my tank down and then fill it up with a higher octane. To date I have never had knock or any other issues with 87.

 

[AlexJeepVB]

Yes, you lose power with 87, more so at higher temps. Up to 30 hp /10 trq, 2mpg loss is expected during summer.
Engine retards timing due to knock. No octane sensors.
Wasn't 2.0 option cost $2k higher?

In the 18's and 19's it was an upgraded additional cost since it came with the eTorque. In the 20+ its actually a discount since they have since removed the eTorque and replaced it with the normal ESS.

 

[tts42572]

Yes, correct.

In my 2021 build, knowing that I wanted an automatic transmission, it would've cost me an additional $1,500 to get the V6 engine.

So I opted for the 2.0T instead to save $1,500. But I'll essentially be spending that money on premium gas the next 5-6 years anyways so will end up being basically a wash.

In the 18's and 19's it was an upgraded additional cost since it came with the eTorque. In the 20+ its actually a discount since they have since removed the eTorque and replaced it with the ESS.

 

[Oldbear]

I stand corrected t should read “87 octane has the SAME BTU as premium”.

 

[SecondTJ]

In the 18's and 19's it was an upgraded additional cost since it came with the eTorque. In the 20+ its actually a discount since they have since removed the eTorque and replaced it with the ESS.

The 2.0 comes with ESS regardless if it has eTorque or not

 

[DadJokes]

The 2.0 comes with ESS regardless if it has eTorque or not

With a very different start/stop experience between the conventional ESS starter and Belt Starter Generator in the eTorque system.

 

[SecondTJ]

With a very different start/stop experience between the conventional ESS starter and Belt Starter Generator in the eTorque system.

Sure, but his statement was completely wrong

 

[AlexJeepVB]

The 2.0 comes with ESS regardless if it has eTorque or not

I meant it was replaced with the normal ESS. Thought that was self explanatory. We all know that they all have engine stop start.

 

[DrBob]

My 2.0 has 22K miles and I couldn't be more pleased. I've averaged about 22 mpg over the life of the engine so far (with ESS disabled manually EVERY time I start the vehicle), in areas with extreme summer heat and pretty chilly winter temps. Most of my driving is in the 3500 to 5000 ft elevation range. We have 89 octane available locally and that's what I run most of the time. I've run several tanks of 87, and I've noticed a little increase in turbo lag and a decrease in responsiveness, especially in hotter temperatures. When I've run several tanks of 91, the engine feels more "zippy" and responsive. Regardless of the mechanical pros/cons of running 87 vs. 91, I have no regrets about the 2.0. Until we have a complete tear-down comparison of engines that have exclusively run one octane or another, my opinion is you should be fine with 87.

 

[LFS]

The Manuel also states that "Use of gasoline lower than recommended octane (91) can cause engine failure and may void or not be covered by the New Vehicle Limited Warranty."

Has anyone had any experience where this has been the case?

 

[Dusty]

The turbocharger compresses the intake air prior to the fuel and air mix getting to where the party starts: the combustion chamber.
* With more pressure, the fuel and air mix explodes more thus making more power.
* With more power per cycle, less fuel is needed to move the vehicle a specific distance.
* Altitude, air temperature, resistance, engine temperature, fuel atomization, fuel octane, etc all come into play, but the bottom line: a forced aspirated fuel-powered engine makes more power than a naturally aspirated one does.

Fuel octane is important. The higher the octane, the more even the fuel moisture burns around the piston head as it waits for ignition. Even burning fuel reduces 'knock' which is what happens when the combustion pressure in a cylinder starts burning fuel mixture before the spark happens. This phenomenon is what makes diesels run, but is not at all good for gasoline engines.

A high compression engine, which is what a pressurized (turbo or supercharger) gasoline engine ultimately is, needs even burning fuel, Premium, to reduce the likelihood of the dangerous 'knocking' or pre-ignition. It sounds a bit like a marble being shaken in an empty tin can, but is actually a piston trying to go backwards before its cycle has ended. Very bad.

In modern engines, there are devices on the engine that listen for 'knock'. When knock is detected, the ignition is instantly retarded to reduce the dangerous knock from occurring. The more the ignition is retarded, the less power the engine can make.

On a forced induction engine, using Premium fuel (high octane = 91 or 93+) reduces the occurrence of knock thereby making more power... because Premium is a even-burning fuel. With 85 or 87 octane fuel, the burn pattern is less even which allows for knock to happen. With knock comes retarded ignition timing which means less power.

So, for a high compression engine, fuel mileage is better using Premium fuel, the engine runs cooler, the engine does not try to explode, and if Premium cost more per gallon than Regular, it is much more economical to use, but not as cheap.

 

[Dusty]

I run what the manufacturer states is required. I use straight 87 octane, and I’ve yet to hear any knock or ping. IF I was going to be in 100+ temps continually OR if I was towing near maximum loads I might reconsider depending on IF I heard anything unusual. Barring that I’ll stick with what works well, 87. Bottom line is that 87 has more btu/gallon than “premium”. Premium has additives to prevent pre-ignition. If there is no pre-ignition, why pay extra for what your engine doesn’t need?

Well, mainly because you probably can't hear the pre-ignition 'knock'. The computer sensors pick up the knock and instantly retard the variable timing to reduce damage to the engine. You likely only hear 'knock' after the timing can't be retarded any more and things are more grenade-like.

Some say that tells them their engine is running at its peak. I say: "Is the blue part of the flame hotter than the yellow part?"

 

[DadJokes]

The pcm has tables that set the knock threshold. The mere existence of knock does not necessarily result in ignition angle retard. Light knock is acceptable and at low cylinder pressures/throttle angle... nowhere near being a danger of failure... even long term.

 

[JeepCharlieJLU]

I know this has beaten to death and I apologize. But I was totally unaware of the whole premium gas issue with the 2.0 Turbo when I placed my JLUR order a few weeks ago and now I'm kinda kicking myself as I might've gotten the 3.6 had I known I'd have to deal with this. Maybe at the end of the day using premium might not be a big deal if you can get better gas mileage with the 2.0 versus the 3.6 but that might be debatable. It seems like reported MPG are all over the board but seems like generally the 2.0 does at least a couple MPG better than the 3.6 on average so maybe that helps offset some of the premium cost.

Anyways, been doing a lot of reading on how these Turbo engines work and reading threads in this forum. It seems people are all over the board with the fuel they're using. I posted a poll in another thread and seems like about 2 out of 3 people are using premium in their 2.0 T engines. But there are many who say they just use 87 and everything is peachy. But IMO, just because you don't notice anything being different doesn't mean different things aren't happening in the engine.

I know the manual says the 87 octane can be used in the engine but that 91 is recommended for optimal performance for hotter temps or when engine is taxed at all. My understanding is that when lower octane gas is used, the engine has systems that will work to compensate for the lower octane gas. But when those systems have to be put to work, your sapping resources from the engine and maybe losing some power/efficiency that may or may not be noticeable depending on what's going on.

So while the engine can run fine on 87 octane gas, it has to do some extra work to run on that gas to try and protect itself from early combustion from using that lower octane gas. If you use 91 octane gas, the engine senses it doesn't have to work so hard to protect against early combustion thereby allowing it to operate at peak performance.

Are my understandings correct?

Have these 2.0T engines been around long enough to know if they'll be fine running 87 gas for say 5-6 years and 100K miles or something? Or are you setting the engine up for some problems with more maintenance needed down the road that maybe could've been avoided by just running higher octane gas?

Obviously, nobody wants to throw money away and buy higher octane gas if it isn't needed. Determining the need is the tough part!

It seems like generally that from what I've read that Turbocharged engines generally like higher octane gas due to the way they operate. I think with all the reading I've done, my plan is to probably use premium of some sort as I plan to keep the vehicle for at least 5-6 years and maybe longer. I'd really kick myself if I skimped on 87 gas and needed a bunch of engine work 4 or 5 years down the road because knocking sensors are worn out or something. I don't want to buy this awesome vehicle for 55K or whatever and skimp on the gas I'm putting in it.

Still kicking myself a little as I probably would've gotten the 3.6 has I known this. Should've done better research I guess. But at the end of the day, it'll probably come out pretty close since the 3.6 would've cost me $1,500 more. Guess it's just a matter of spending more up front or spending more $300 a year more for gas over the next 5 years. So I guess it doesn't really matter much. I initially thought I'd be saving money with the 2.0 but guess not.

I bought a 2020 JLUR Recon with 2.0L turbo (only engine available in Recon) and was concerned if driving on 87 octane would result in significantly lower performance than premium gasoline. I read the owner's manual and it stated that 87 octane can be used but for optimum performance, 91 octane is recommended. Therefore, I've maintained using regular gasoline after I drove off the dealer's lot for about 1.5 months. The 2.0L had great pep and the power was sufficient to make me smile. Curiously, I changed to 91 octane to see if there was any kind of marked change in performance. On premium gas, I noticed a TINY improvement in engine response and power. However, to be honest, if I had to make a comparison under a blind test evaluation, I probably could not tell you if I had been driving under regular or premium gasoline. Time and mileage will tell if using 87 octane results in a gradual decline in engine performance.