Fuel economy / miles/gallon

[henryb]

The stated fuel economy for my 3.8 liter Hyunai is 28 miles per gallon ...highway driving. I am consistently getting 33.2 MPH driving with AC on at steady 70MPH on cruise ...64 mile trip. I am really pleased. I thought it might be because I am using high test gas but this attached info says NO to that theory. Love my Genesis thus far great smooth ride. You all get this good result also with the 3.8 V6 ? https://www.youtube.com/watch?v=FPPkPAbzwbU

 

[Mark_888]

The Hyundai Genesis V8 definitely gets better gas mileage with premium, according to Hyundai's own published specs (it can run on regular or premium according to the owners manual). Hyundai submitted their EPA mileage rating tests using premium.

The V6 is less clear, but I have found that I get better gas mileage with mid-grade on my Genesis V6 (actually a custom 50-50 mix of premium and regular due to the way the mid-grade is priced in most places).

Do not pay any attention to "general" articles (or videos) about the relationship of octane level and fuel mileage. While it may be true that most cars will not get better gas mileage with higher octane, that is a generalization that does not apply to all engines.

Most people who have independently tested their fuel mileage say that the MPG calculated by the instrument cluster is about 1 MPG too high compared to independent testing methods.

 

[henryb]

Thanks for your response. I would think that higher octane would result in higher MPG as that gas has more stored energy. But is my 33.2 MPG or even 32.2 MPG surprising or have you (or others here) also experienced this? I was expecting 28MPG

 

[Mark_888]

Thanks for your response. I would think that higher octane would result in higher MPG as that gas has more stored energy. But is my 33.2 MPG or even 32.2 MPG surprising or have you (or others here) also experienced this? I was expecting 28MPG

Higher octane does have more energy, but the engine must have some kind of variable tuning for the engine to take advantage of it. Clearly, older engines are only designed for one octane level, but some new engines can adapt and take advantage of the higher octane with more HP and better MPG. But it depends on the engine.

I am not sure why the EPA Highway mileage is so far off, but just about everyone else has experienced better than EPA ratings.

 

[henryb]

Thanks Mark

 

[Bill K]

I have yet to read anything printed from Hyundai that claims the Premium gas will increase mileage. On the V8, Hyundai states that Premium will give you a few more horses under the hood.
My best mileage on the interstate at 65 mph has been 31. At 70-75, it drops to 30.

 

[landtuna]

Thanks for your response. I would think that higher octane would result in higher MPG as that gas has more stored energy. But is my 33.2 MPG or even 32.2 MPG surprising or have you (or others here) also experienced this? I was expecting 28MPG

My cousin, who also owns a 3.8, gets in the low 30's as well.

 

[Mark_888]

I have yet to read anything printed from Hyundai that claims the Premium gas will increase mileage. On the V8, Hyundai states that Premium will give you a few more horses under the hood.
My best mileage on the interstate at 65 mph has been 31. At 70-75, it drops to 30.

ON the 5.0 V8, Hyundai used premium when submitting results for the EPA fuel mileage testing. Usually, if an engine can develop more HP with higher octane, it can also result in better MPG at a given HP.

Hyundai Motor America would be idiots to use premium for EPA fuel mileage testing if they could have gotten the same results with regular.

 

[shagnat]

I would love to find the information Mark888 references. A link or something. I love being informed.

 

[Mark_888]

I would love to find the information Mark888 references. A link or something. I love being informed.

Please provide the exact information you are referring to.

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Help support this site so it can continue supporting you!

 

[jlindh]

I'd also be interested in the information. Specifically, "Hyundai used premium when submitting results for the EPA fuel mileage testing", "The Hyundai Genesis V8 definitely gets better gas mileage with premium, according to Hyundai's own published specs" and finally "Higher octane does have more energy"

 

[Mark_888]

I'd also be interested in the information. Specifically, "Hyundai used premium when submitting results for the EPA fuel mileage testing"

Go to the EPA website. They publish the EPA city, highway, and combined gas mileage ratings and fuel used (regular, premium, etc). As I am sure you know, Hyundai recommends premium for the Genesis 5.0 V8 (owners manual), but says that regular gas can be used.

Your new vehicle [V8] is designed to use only unleaded fuel having an octane number ((R+M)/2) of 87 (Research Octane Number 91) or higher.For improved vehicle performance, premium unleaded fuel with an octane number ((R+M)/2) of 91 (Research Octane Number 96) or higher is recommended.​

As I previously mentioned, Hyundai does not explicitly say that premium gas gets better mileage, but they would be imbeciles to conduct EPA testing with premium if they could get the same mileage with premium. Numerous Genesis owners on this forum over the years have reported slightly better MPG with premium.

I didn't post the other two quotes that you wanted links for.

 

[shagnat]

n the same results with regular.

 

[Mark_888]

ON the 5.0 V8, Hyundai used premium when submitting results for the EPA fuel mileage testing. Usually, if an engine can develop more HP with higher octane, it can also result in better MPG at a given HP.

Hyundai Motor America would be idiots to use premium for EPA fuel mileage testing if they could have gotten the same results with regular.

As I mentioned above, check the EPA website where they publish the fuel mileage results. The EPA lists the fuel used (regular vs premium).

As to whether "Hyundai Motor America would be idiots to use premium for EPA fuel mileage testing if they could have gotten the same results with regular," there is obviously no link for that, and is my opinion based on logic.

 

[kn5owa]

My 5.0 V8 gets 27 mpg on the open road - which is what I bought it for. ---- I use the '06 Sonata for "in-town driving".

Maybe some of the gasoline aficionados can explain why Shell makes outrageous claims about nitrogen in their gas.

Red Adair used the stuff in Kuwait to put out oil well fires.

In plain English, nitrogen doesn't burn so well -- maybe a little hype here? As always with additives. Remember STP and BG?

 

[shagnat]

As I mentioned above, check the EPA website where they publish the fuel mileage results. The EPA lists the fuel used (regular vs premium).

As to whether "Hyundai Motor America would be idiots to use premium for EPA fuel mileage testing if they could have gotten the same results with regular," there is obviously no link for that, and is my opinion based on logic.

Nope, not there, Mark888..... at least not where I could find it.

 

[Mark_888]

Nope, not there, Mark888..... at least not where I could find it.

I am not going to fall for that one. It was there a few years ago when I looked.

I you want me to find it for you, there is a $25 charge via PayPal. Send me an IM if you are interested.

 

[shagnat]

I am not going to fall for that one. It was there a few years ago when I looked.

I you want me to find it for you, there is a $25 charge via PayPal. Send me an IM if you are interested.

Nothing to fall far, my friend. If you don't have time or unable to find it, that's ok.... Don't know why you would think I was trying to "pull one over on you". I'm not a lazy person.

If you can find it on the EPA website, I'll buy the first round..... how 'bout that?!

 

[homeofstone]

Is this the info wanted http://www.fueleconomy.gov/feg/PowerSearch.do?action=noform&path=1&year1=2010&year2=2011&make=Hyundai&model=Genesis&srchtyp=ymm

 

[shagnat]

Is this the info wanted http://www.fueleconomy.gov/feg/PowerSearch.do?action=noform&path=1&year1=2010&year2=2011&make=Hyundai&model=Genesis&srchtyp=ymm

Oh, so it's on the "www.fueleconomy.gov" website..... thanks tons!!!