Various forum members state to use high (92) octane gas in a GDI in even a non - turbo engine . I have a Hyundai 2.4L non turbo GDI engine and have tried several tanks of high octane (92) gas in it : While the engine naturally has greater pep with the higher octane gas - my gas mileage is better with the 87 octane gas . Please explain the added benefit of using high octane gas in a GDI engine (i.e. less intake valve deposits , extended spark plug life , etc. ) ? Thanks in advance !
Why Recommend High Octane Gas In GDI (non - turbo) Engine ?
- Thread starter ChrisD46
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High Compression GDI Engines With 87 Octane ?
I believe my Hyundai GDI Sonata 2.4L non-turbo has a compression ratio of 13:1 ... Makes me wonder how on earth Hyundai engineers can make 87 octane work in such a high compression engine ? Also , even though 87 octane or higher is recommended in the OM - how would you tell what the best octane...
bobistheoilguy.com
Please note that hi-test fuel, like AKI 92, may be ethanol-free. As such, it certainly has a longer storage life.
But the main reason, to my way of thinking, is that a direct injected engine can be held-off pinging by 1) retarding the ignition; or 2) richening the mixture. Oftentimes it is a combination of the two. It appears that DI engines, then, can (with short-cycle driving) tend to accumulate fuel in their crankcase... due to this enrichening to quell ping. If you can't help short-cycle driving, then if you use high octane fuel, you will lessen the NEED for the engine to enrichen the mixture, and you will in theory reduce the crankcase dilution that occurs.
But the main reason, to my way of thinking, is that a direct injected engine can be held-off pinging by 1) retarding the ignition; or 2) richening the mixture. Oftentimes it is a combination of the two. It appears that DI engines, then, can (with short-cycle driving) tend to accumulate fuel in their crankcase... due to this enrichening to quell ping. If you can't help short-cycle driving, then if you use high octane fuel, you will lessen the NEED for the engine to enrichen the mixture, and you will in theory reduce the crankcase dilution that occurs.
wemay
Site Donor 2023
In every car/SUV I've owned over the past 15 years I've used 87 octane. I use 87 octane in both 2.0T in my signature, one being a Hyundai. Zero issues. Maybe it's the warm climate down here.
Three of those were H/K 2.4GDi. One did develop a ping at part throttle around 80k miles but it went away with a spark plug and battery change, not premium fuel.
Three of those were H/K 2.4GDi. One did develop a ping at part throttle around 80k miles but it went away with a spark plug and battery change, not premium fuel.
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It my 2006 Hyundai Tucson, it really didn’t care what grade of fuel I used in it. It had multiport injection and a lower compression ratio. In my wife’s 2013 Optima, that was a different story. It had a 13:1 compression ratio and a ECO switch that lugged the engine. When all of the Hyundai/KIA engines were falling, I instructed my wife to turn off the ECO switch and buy premium gas (93 octane). We never had any engine problems. I also went to 5W30 oil instead of the 5W20 recommended by Hyundai/KIA. I don’t see how you get better fuel mileage on regular over premium gas. Are you aware that winter blended fuel has a lower energy rate than summer blended fuel? Hyundai/KIA went with an upgraded knock sensor campaign to get a handle on some of their engine failure. My upgraded knock campaign was to turn off the ECO MODE, run premium fuel and use 5W30 oil. And, follow the recommended oil change intervals.
hyundaiengineinfo.com
Software Update - Hyundai
Software Update Engine Monitoring Technology And Extended Warranty In an effort to continually improve our product and as prompted in part by the recalls, Hyundai has developed new engine monitoring technology called a "knock sensor detection system." The technology is being installed on certain...
hyundaiengineinfo.com
All else being equal except the octane, it won’t any difference to deposits, spark plug life, or anything else. That being said, Top Tier>non-top tier, and some retailers do advertise their premium as having more detergents in their premium grade.
From the manual I saw online, they say “87 octane or higher” which hints at it being able to take advantage of the higher octane fuel. Will you notice a real world difference? Unlikely.
From the manual I saw online, they say “87 octane or higher” which hints at it being able to take advantage of the higher octane fuel. Will you notice a real world difference? Unlikely.
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Low speed preignition maybe? Honestly I don’t know and wouldn’t try it, instead I’d stick to using a top tier fuel. They say that’s important but even then, when I did that, I still had misfires and hesitation/timing issues with my direct injection cars. So I’m not exactly sold on anything during the problems.
In the cars I've had with knock sensors, I find they run a little peppier with higher octane in hot weather and cranking the AC.
So when I know there's 90+F weather coming I'll add 1/2 tank of premium to 1/2 tank of 87.
In my area that's cheaper than buying 89 midgrade.
So when I know there's 90+F weather coming I'll add 1/2 tank of premium to 1/2 tank of 87.
In my area that's cheaper than buying 89 midgrade.
No, it’s not hinting at being able to take advantage of higher octane. The owners manual is worded that way simply to inform drivers that the vehicle can run safely on 87 or higher.
Most ECM’s do not have separate tuning maps for higher octane performance. Some do, most do not.
Usually the owners manual simply states “This vehicle is designed to run satisfactorily on 87 octane” in that case. We will never know without access to a dyno, watching live data for knock/ignition timing, or Hyundai coming out and saying for certain. They also don’t use separate maps. There is one map that is constantly adjusting itself within a set boundary. If it can only get 25° of advance on 87 and 35° on 93, with a ceiling of 40, that would be taking advantage of the higher octane. Small change and in the grand scheme of things absolutely unnoticeable by pretty much everyone, but it’s taking advantage of it.
Nick1994
$100 site donor 2024
I had a 15' Sonata 2.4L. It would ping on 87, so I ran 91 and it was nice and quiet. And I'm not one of those type that can feel or hear how smooth my car runs on one type of oil etc., there was definitely a difference. Sometimes I'd switch to 87 to see and sure enough, it always came back pinging. I put new plugs in at 75k and it didn't make a difference.
My Genesis is GDI but no pinging on 87.
My Genesis is GDI but no pinging on 87.
I have heard of Hyundai Theta owners with pinging issues running 87. If that is the case with you then bump up to a higher octane. If not, stick with 87.
I do chose to run Shell "V-Power" in our Jetta since is is Turbo / DI for peace of mind. It is only a couple dollars more per fill up, and when you get 30 MPG city / 40 MPG highway the extra cost is negligible.
I do chose to run Shell "V-Power" in our Jetta since is is Turbo / DI for peace of mind. It is only a couple dollars more per fill up, and when you get 30 MPG city / 40 MPG highway the extra cost is negligible.
Kestas
Staff member
Theoretically, higher octane should make for a more efficient engine, which is important for manufacturers who want to meet CAFE standards. I don't know why it doesn't work in your car.
There have been numerous tests done by multiple respectable sources that have shown NO benefit to using higher octane in cars that specify 87 octane. Some manufacturers have the ECM tuned to take advantage of higher octane fuel so yes, there is different fuel/timing mapping on some ECMs for higher octane fuel.
The overwhelming outcome of the tests have shown that there is no performance or MPG benefit to using higher octane fuel when it isn’t required. In fact, some tests have shown worse performance and mpg with higher octane.
I wondered about this too.
As for the octane requirements, 87 will run fine but perhaps not optimally. I run 93 Shell and I have noticed better response. The manufacturer doesn’t push the higher octane because that might be a turnoff to prospective buyers.
My Snotta with a Thetta2 2.4 does get a little better fuel economy on premium, but not enough to justify the extra cost. I was told by the dealer that premium fuel is cleaner burns cleaner so the engine lasts longer. Well my new Thetta 2 needs only last as long as the old one on regular Guzzaline and I will be happy....
This is a good read.