My 2017 Hyundai 2.4L GDI engine runs sluggish with 87 octane in high heat & humidity ... Conversely using high octane (92 or 93) makes a significant difference in engine pep during high heat & humidity . I'm not sure why higher octane makes such a difference in Summer months with improved engine performance - I'll switch back to 87 octane in the Fall when temps & humidity drop again . Your thoughts & experiences ?
Higher Octane Gas in Summer ?
- Thread starter ChrisD46
- Start date
I have the same exact experience when running E85 in my Dart. E85 does have higher octane but less BTU content. The performance difference may have something to do with greater humidity in the air......not sure.
Hey Chris, my 2018 Sonata with the 2.4 DI performs exactly how you described. This summer is the first HOT summer since owning it, and this is the first time I’ve noticed the sluggishness. Seems to be after driving for about 20+ mins in 100+ degree heat it starts driving sluggish. Throttle response is very delayed. I’m assuming this is normal. There are no unusual noises from the engine, no pinging or knocking. It kind of reminds me of back in the day with carburetor engines, they would fall flat on their face in hot weather with 87 octane too.
My WAG is that warm air is less dense and when running 93 the vehicle doesn't have to retard timing. Perhaps the engine is more sensitive to heat soak which is typically an issue found only with turbo engines.
Edit: I noticed your engine runs a high compressions ratio 10.3 - 11.3 : 1. I'm going to say heat soak.
Edit: I noticed your engine runs a high compressions ratio 10.3 - 11.3 : 1. I'm going to say heat soak.
88e15 cools and adds octane, 20 cents a gallon cheaper worth a try
Not a Georgia thing.
Depends where you live
(See 88 drop down for a list)
I WISH! I've been using it for a couple of years. It "seems" to reduce the takeoff lag I get in the summer just a bit, but I haven't objectively tested it. There is only one station in my area that has E15 (QT) and it's only 5 cents a gallon cheaper than regular. I should probably stop messing with it because after seeing this post I was reminded that most people on BITOG are reporting 20 cents a gallon savings. That stands a better chance of offsetting the fuel economy loss.
Normal midgrade and premium is $1-$2 a gallon more than 88e15
So if your choice is cheap 88 or expensive 89 you would need to loose a Lot of fuel economy to make a difference.
When I know a heatwave is coming I sometimes add 1/2 tank of premium to 1/2 tank of 87 I normally use.
Did this also with my previous 2006 Toyota Matrix.
Haven't done it lately with the elevated gas prices.
Intake air temperature greatly affects tendency towards spark knock.
Did this also with my previous 2006 Toyota Matrix.
Haven't done it lately with the elevated gas prices.
Intake air temperature greatly affects tendency towards spark knock.
87 is Top Tier last I checked (for Fleet) even nicer^ Is the 89 + 91 non E Top Tier ? If so , MUST BE NICE ! "^
88 has a “is sold by a different provider “ disclaimer at most pumps
I’ve noticed my truck seems sluggish running 87 in high heat and humidity. I just added 10 gallons of 92 to 13 gallons of 87 which puts me at about 89 (which is recommended) and it definitely feels better.
I've actually been choosing between 87 and 88. My 2012 Mazda3 does not require anything more. Fuel economy loss is barely perceptible. I guess I'm taking issue with the fact that E15 should be significantly lower priced.
5 cents difference was worth it when RUG was $1.59/gallon
5 cents “savings” does not make sense when gas is $4.10+ If your car runs fine on RUG.
For our 2017 Explorer with the 2.3L EB Ford recommends 91 or greater Octane in "hot" temperatures. It's in the owner's manual. However at $0.60+/gallon for premium we can live with the "lower performance" of regular. It has no bad effects other than premium makes it peppier in the heat. Been doing this for 5 years, no problems, just slower
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