Genesis 5.0 fuel choice?

[Nikgen]

I made the statement that premium used in the V8 results in better MPG than using regular gas. I made no statements about the calculation of a purely economic evaluation. Even if it makes no sense economically to use premium (which I don't know one way or the other) it is wrong to say the V8 gets the same MPG with either fuel (regular or premium).

I never said it did - I was questioning whether an extra 7 hp was worth paying more for - that's all.

 

[Mark_888]

I never said it did - I was questioning whether an extra 7 hp was worth paying more for - that's all.

OK, that's fair, but then you should pose the economic question to those who have made the choice or advocate running premium. I was just stating facts (at least to the best of my knowledge).

 

[Nikgen]

OK, that's fair, but then you should pose the economic question to those who have made the choice or advocate running premium. I was just stating facts (at least to the best of my knowledge).

Sorry, I was not intending the question for you - meant as a general comment.

 

[Nikgen]

BTW - 2016 Brochure lists 407 hp with regular fuel and 420 hp with premium - so a 13 hp difference for those who care.

No hp difference based on fuel choice shown for the 3.8, suggesting that premium fuel is a waste of $ for that motor - if the assumption was extra power with premium fuel?

 

[homeofstone]

Why is there always a discussion on gasoline grades when driving 20,000 miles a year you may save 400.00 in a year( less than $8.00 a week) , given 20mpg and .40 difference between reg. and premium.

 

[Nikgen]

Why is there always a discussion on gasoline grades when driving 20,000 miles a year you may save 400.00 in a year( less than $8.00 a week) , given 20mpg and .40 difference between reg. and premium.

might even be a "wash" if Premium improves mpg enough...

 

[Alwaysforward]

It does improve fuel mileage in the test I have done. Almost a wash.

 

[dereyes]

I tried both premium and regular, I use regular. I found no difference in HP, I did find that premium do burn faster then regular.

 

[vast]

I understand that going with 93 octane gives the 5.0 a 13hp bump. I fill up regularly with 93. Would the 5.0 like race gas? Going to the drag strip tomorrow night.

 

[glennk]

I understand that going with 93 octane gives the 5.0 a 13hp bump. I fill up regularly with 93. Would the 5.0 like race gas? Going to the drag strip tomorrow night.

Don't think you can squeeze any more horsepower from a non- turbo/supercharged engine.

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[Mark_888]

I understand that going with 93 octane gives the 5.0 a 13hp bump. I fill up regularly with 93. Would the 5.0 like race gas? Going to the drag strip tomorrow night.

I don't know if Hyundai has published numbers on the 5.0, but on the 4.6 Tau V8 (2009-2012) Hyundai claimed it was a 7 HP bump. I doubt that race gas will help unless you change the ECU and some other components.

 

[glennk]

http://www.motortrend.com/cars/hyundai/genesis/2015/2015-hyundai-genesis-v8-first-test/

"Power from that 5.0-liter V-8 is down from the 2014 model’s 429 hp at 6400 rpm to 420 hp at 6000 rpm, but torque is up. The Genesis V-8 now produces 383 lb-ft at 5000 rpm, up from the 2014 model’s 376 lb-ft at 5000 rpm. The Genesis V-8 is happy to sip regular fuel instead of premium, but then it only makes 407 hp and 372 lb-ft."

- - - Updated - - -

Hyundai website:
http://www.hyundainews.com/us/en/models/genesis/2015/specifications

 

[mtriples]

Since this has been revived, I'll add some tuning experience into it as well.

-The average engine is designed for regular gas, and will see little to no difference in MPG or power.
-Higher octane gas tends to have a slightly lower specific gravity...this translates to slightly less energy. Ethanol has a very low air fuel ratio...E10 gas has an ideal ratio of 14.04, vs 14.7 for E0...this means they run richer. However, higher octane gas IS more stable, leading to better POTENTIAL ignition timing.
-For an NA motor designed for high octane gas like the Tau, the better ignition timing is usually where you make up MPG. You make the same torque with slightly less fuel. Another minor consideration is that advancing your timing tends to reduce EGT temperatures a bit as well, since more of the energy is used for driving the engine.
-I doubt the cleaner engine part. Perhaps some gas brands add extra detergents for this, but I wouldn't just assume they all do. Ethanol DOES add some benefit here though.

All of this assumes that your ecu can adjust for whatever gas you're running. And every engine is different in how much timing advance is useful...some have little extra overhead, some have lots of room. Alwaysforwards fuel study definitely shows that there's enough overhead to matter.

Personally, I'm expecting to see a marked improvement in fuel economy with tuning on the 5.0, especially at higher loads. I had my 2015 dynoed...the AFR's dropped steadily richer through the whole RPM band, down to maybe 11:1 IIRC. The curve looks more like what you'd see on a turbo vehicle, not the mostly steady line from most NA engines. I can see if I can find the snapshot in my phone later, if people are interested.

-Matt

 

[AustinTX]

http://www.motortrend.com/cars/hyundai/genesis/2015/2015-hyundai-genesis-v8-first-test/

"Power from that 5.0-liter V-8 is down from the 2014 model’s 429 hp at 6400 rpm to 420 hp at 6000 rpm, but torque is up. The Genesis V-8 now produces 383 lb-ft at 5000 rpm, up from the 2014 model’s 376 lb-ft at 5000 rpm. The Genesis V-8 is happy to sip regular fuel instead of premium, but then it only makes 407 hp and 372 lb-ft."

I am absolutely willing to bet money on the fact that no one can tell the difference between these three engine tunes if they were driven one after the other. These are differences that are within 3% - and depending on the actual engine you have in your car that's what I would expect the normal distribution to be from checking the performance statistics of all the engines they build.

These differences are theoretical, and can only be measured on a dyno.

HP: 407 - 420 = 3.2% increase
Torque: 372 - 383 = 2.9% increase

All these measurements are at RPM ranges that no one driving a Genesis would ever be driving at: 6000 RPM and 5,000 RPM are not engine speeds that my engine experiences on a regular basis.

Regular fuel vs Premium fuel in Austin, TX today:

$2.12 - $2.61 = 23% increase

One pays 23% more for fuel for an at best 3% (i.e. statistical noise) increase in "performance". At 12,000 miles/year and 18 mpg, one would be wasting over $300 extra on paying for gas - for virtually no improvement.

My 2 cents. Not even worth real 2 cents ...

 

[lobsenza]

I agree....

 

[vast]

I am absolutely willing to bet money on the fact that no one can tell the difference between these three engine tunes if they were driven one after the other. These are differences that are within 3% - and depending on the actual engine you have in your car that's what I would expect the normal distribution to be from checking the performance statistics of all the engines they build.

These differences are theoretical, and can only be measured on a dyno.

HP: 407 - 420 = 3.2% increase
Torque: 372 - 383 = 2.9% increase

All these measurements are at RPM ranges that no one driving a Genesis would ever be driving at: 6000 RPM and 5,000 RPM are not engine speeds that my engine experiences on a regular basis.

Regular fuel vs Premium fuel in Austin, TX today:

$2.12 - $2.61 = 23% increase

One pays 23% more for fuel for an at best 3% (i.e. statistical noise) increase in "performance". At 12,000 miles/year and 18 mpg, one would be wasting over $300 extra on paying for gas - for virtually no improvement.

My 2 cents. Not even worth real 2 cents ...

It's only a few dollars difference at the pump. 429 hp vs 407 hp to me is worth it.

 

[AustinTX]

It's only a few dollars difference at the pump. 429 hp vs 407 hp to me is worth it.

It's your money, and you may spend it any way you wish - I don't get the "few dollars difference at the pump" comment though. It adds up to > $300/year at 12,000 miles, unless my math is incorrect. That fact that you pay for that $300 in "installments" (every time you fill up) doesn't make it any cheaper.

Have you ever filled up with "regular" gas, and did you experience any noticeable difference?

 

[Midnightsun]

What makes me laugh is all those little turbo charged 4 bangers that equate to higher MPG IF you drive them with small pedal input other wise they are really no better than their V6 non turbo equivalent. Most if not all use premium fuel however if you account for the price difference compared to regular fuel equivalents, it equates to a rather substantial difference if you convert the MPG to $/Mile

Honestly I do not think anyone gives a hoot about MPG because at the end of the day it's the operating cost that we are interested in. Unfortunately we are brainwashed into MPG. Take the example of fuel costs Austin TX supplied above and the turbo version running premium basically consumes 23% more than advertised when compared to a non premium fuel engine with the same MPG rating. Bottom line is it costs me less to operate my AWD V8 on regular mile for mile than it does to operate a V6 if the owner used premium.

 

[redandblackpack]

I have only been using regular so far. I may try premium at some point to see if I can tell or see a difference.