Gas in the 2.0T - Is my understanding correct?

Warped

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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 also have a Ford F-150 with the twin turbo V6 and the owners manual states the same as the Jeep manual. I have run numerous tests towing and normal driving and found no noticeable difference in fuel economy or performance using premium over regular. My 2.0T in the Jeep runs plenty good on the regular as does the F-150. Just enjoy it and the fuel savings over the 3.6. Don't waste your time and energy on regrets, waste it on Jeep mods. :)





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scottedontknow

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Telling people to ignore knock is irresponsible. Knock is bad for an engine, even if the ecu adjusts. The event happened and you can’t undo that. Saving a few bucks a year in gas is going to cost an engine down the line.
"While operating on gasoline with the required octane number, hearing a light knocking sound from the engine is not a cause for concern. However, if the engine is heard making a heavy knocking sound, see your dealer immediately. Use of gasoline with a lower than recommended octane number can cause engine failure and may void or not be covered by the New Vehicle Limited Warranty. "


as per the OWNERS MANUAL. Again JEEP SAYS THIS IS NOT A CAUSE FOR CONCERN". But hey i guess you are the one who spent the million upon millions of dollars in R&D into what is good and not good for this 2.0t. Telling people to ignore the owners manual is irresponsible.
 

guarnibl

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I don't notice any knocking with 87. Sounds identical to when I run 91. FWIW, Porsche says the same thing and recommends like 92 or 93 or something. We can't even get that out here very easily. I'll run the required octane. If that ends up being an issue, I don't care. The only time octane concerns me is if I'm beating on it, summer, altitude (i.e., more strain through passes).
 

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I run 93 in mine. Like others have said if you drive normal I'm sure 87 is fine. I run 93 for two main reasons. First I got this engine for the fun driving experience and enjoy getting the best performance out of it. Second is that with these direct injection engines I have read that they can get bad carbon build up and the 93 with more cleaner additives will prob help that long term. Let me also note that I have a very short commute and drive maybe 2500-5000 miles max a year so its not that big of a hit cost wise.
 
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tts42572

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So, took it upon myself to do some additional research today and called a large JEEP dealership and talked to their service manager who seemed very knowledgeable. I asked him his opinion on using 87 octane in the 2.0T engines.

His response was that 87 is fine in the vehicle and the vehicle will work great for most people and many may not even notice any difference in their day to day driving. He said that these engines have been tuned to work and maintain good performance with 87 octane and they have features that will compensate for that type of gas being used.

However, he said 91 or higher octane is definitely optimal for Turbo engines with the way they work for peak performance. He said he has a 2.0T himself and will only put 93 octane in it. Also feels that it will be better for the engine over a long period of time. He said if you're only planning to keep the vehicle for 4-5 years and 50-60K miles or something, feed it 87 and let somebody else worry about any issues that might happen later. But if you're planning to keep it for longer, he'd recommend feeding it premium.

Overall, said it's a great engine and he felt it's probably the wave of the future for this vehicle outside of those that go with hybrid or diesel.

Didn't really say anything that was different than what others have been saying in threads here but it was nice to hear it from somebody that works closely with these vehicles.

So think I've gotten enough information. I've been wanting this vehicle a long time and planning to take care of it in hopes I can maybe pass it to my son 6 or 7 years down the road (he's 11 now). I'm sure 87 would probably be fine but I'll be running premium at least to start with and we'll see how it goes.
 

Lil Red

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Below came from TrueCar.

With certain vehicles like the Ford F-150 and Mazda MX-5 Miata, automakers recommend premium gas but don’t require it. Research by AAA found that these vehicles saw a slight increase in performance and fuel economy using premium gas. For those who drive a luxury or performance vehicle, premium gas can help emphasize your vehicle’s intended characteristics.
 

BigGreen

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Inb4 87 diehards say the service manager doesn’t know what he’s talking about.
 

redracer

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keep in mind, higher octane is to deal with higher compression, and it’s not just limited to turbo engines.
There are lots of us 3.6 owners that are running premium fuel to deal with the excessive engine knock that our high compression (11:1 is quite up there) engines seem prone to, especially when hot.
I have had my engine knock so bad that it almost stalled when starting up a steep paved road in 1st gear after climbing 8000 feet in a half hour.
 

srt20

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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?
Please stop repeating this. It is wrong!
 

89TransAmWS6

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I run 93 in mine. Like others have said if you drive normal I'm sure 87 is fine. I run 93 for two main reasons. First I got this engine for the fun driving experience and enjoy getting the best performance out of it. Second is that with these direct injection engines I have read that they can get bad carbon build up and the 93 with more cleaner additives will prob help that long term. Let me also note that I have a very short commute and drive maybe 2500-5000 miles max a year so its not that big of a hit cost wise.

GDI engines do have problems with carbon buildup..but by design the same reason they have a carbon problem is the same reason higher octane fuel or even traditional "cleaner" additives wont help. Remember you are injecting the fuel directly into the engine which has a ton of great benefits but you lose the advantage of having the gasoline "wash" the intake valve like you would in a traditional fuel injected (or even carb'd) engine. Not saying there is no benefit in terms of cleaning...just not for the "major" problem.

With that being said I do typically run premium in mine as well. Several times I have run 87 including the initial fill-up from the dealer and have not seen any real difference. I have had my '20 for just over a year and just turned 5k miles so I really cant comment on fuel economy vs cost. Hell, to be fair I am probably the guy that should be running 87 but as said above...since I dont have a far commute the cost isnt really a big deal.
 

DadJokes

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As a past trained/former high end engine builder, occasional light knock is ok. It is one sign that peak combustion chamber efficiency is being taken advantage of IE- more complete burn and heat generation. Ideally, in racing and the street, you ride that line of rich/lean in a fuel mixture and ignition advance. In a known combination, utilizing computer control technology, it’s much easier and safer to ride that line in OEM applications.

Heavy, constant knock is hell on your ring lands, plugs and can make for a bad day when it’s out of control.

I’m sure that the factory has likely tested many scenarios with their tuning so 87 is ok but premium will let the limits in tuning maximize cylinder pressure/efficiency. In an NA, non turbo etc especially, higher elevation towns have gas stations that sell lower octane many times because the same engines max cylinder pressure/power production will be lower, thus generally needing less octane to prevent knock. I’d experiment there, especially on long steep inclines to see what fuel does the job best for you.
 

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Also consider getting a gas card with one of the big chains. It can often make 91 or 93 significantly cheaper as they discount it more as the regular is usually the price advertised so have to be competitive with the local low price.

Around here WaWa gets me 93 octane for $0.12 more then regular - so no reason not to do it for $2 a fill.
 

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I run ethanol free 91 in all my vehicles here on Maui. I provides a slight increase in mpg and seems to run very well. It's usually very warm here, I don't know what effect that has but ethanol free works well. It also has a better shelf life, I store some for generator and small engine use.
I run and recommend ethanol free as well (I have the 3.6) and achieve about 22 mpg (6M) with the 32" MT's.
 

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Also consider getting a gas card with one of the big chains. It can often make 91 or 93 significantly cheaper as they discount it more as the regular is usually the price advertised so have to be competitive with the local low price.

Around here WaWa gets me 93 octane for $0.12 more then regular - so no reason not to do it for $2 a fill.
Wawa! Someone in North Carolina once asked me, " When you say Wawa, are you taking about Walmart?" (as if...) I have never seen such rage on my wife's face....
 

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