2012 genesis 3.8

[joeferrer]

so i just got a 2012 genesis v6 and wanted to ask you guys who have had this car model a few questions.

the dealer suggested regular gas for this car but i read somewhere that prem gas would give me a extra 6hp or so. anybody know if that is true?

wanted to also ask if yal had any ideas for some cheap upgrades for the car hp/speakers etc

 

[Mark_888]

I would try some mid-grade gas see if you like it. I have found that the MPG on my 3.8 V6 increases with mid-grade (compared to regular), but gets no additional benefit from premium. You mileage may vary. My engine also seems more responsive with mid-grade. Actually, I normally use a blend of regular and premium, because (based on octane) it is usually a little cheaper that way.

I am not sure if it has been documented as to and increase in HP and/or gas mileage for the V6 with higher octane. Hyundai has said that the V8 gets about 6 more HP with premium, and they perform the EPA mileage test with premium on the V8.

 

[joeferrer]

how much more mpg do you think you get using the mid grade gas and
what about engine oil. do you use the standard oil they suggest or do you use synthetic oil or a different brand.

 

[dougmcp]

Depends how you drive the car and the performance you demand out of it. With the 3.8, I'm an easy driver not trying to beat everyone away from the light or outperform anyone on the track so I use regular with zero issues. I'm not convinced that if you got slightly better fuel economy that it would balance out the extra $0.10 a gallon.

 

[Mark_888]

how much more mpg do you think you get using the mid grade gas and
what about engine oil. do you use the standard oil they suggest or do you use synthetic oil or a different brand.

I get about 1 MPG more with mid-grade (usually Shell or Chevron) on the highway. I can feel the increase in responsiveness when accelerating. Also, my engine runs a bit quieter (much less chance of detonation).

I use Mobil 1 5W-30 EP (Extended Protection) and I do the oil changes myself. Use only the Hyundai OEM filter. The only reason why Hyundai does not recommend synthetic is that it increases the cost of ownership for customers, and Hyundai typically sells to buyers who are sensitive about that sort of thing. That same engine has been used on other Hyundai and Kia vehicles.

As far as oil brand, the Hyundai "association" with Quaker State (owned by Shell, who also owns Pennzoil) is pretty much of a marketing agreement, not based on any idea that Quaker State is actually better than other major oil brands. But Quaker State synthetic is far better than any conventional oil.

 

[Ragnar]

I'm not at all convinced that if your model calls for unleaded regular there's any advantage to using higher grades of fuel,every expert we ever asked tells you it's a waste of money,on the other hand synthetic oil is absolutely the way to go for today's engines.
Unfortunately the finance guy talked my wife into a package deal on oil changes and I couldn't change her mind! So we're stuck with them for 3 years lol.

 

[Mark_888]

I'm not at all convinced that if your model calls for unleaded regular there's any advantage to using higher grades of fuel,every expert we ever asked tells you it's a waste of money,on the other hand synthetic oil is absolutely the way to go for today's engines.
Unfortunately the finance guy talked my wife into a package deal on oil changes and I couldn't change her mind! So we're stuck with them for 3 years lol.

It depends on the engine (and sometimes on the age of the engine) as to whether higher octant helps. If an engine is only designed for regular, then premium is usually too much octane and a waste, but a little more octane above regular can provide benefits and reduce pinging (which engines are more prone to encounter as they get older).

One problem with the "experts" is that they are usually viewing the world through a rear-view mirror. In the old days, engines were only capable of exploiting one octane level, but with newer electronically controlled engines, some of them can make use of higher octane. I prefer to experiment myself, on my own engine, rather than to rely on so-called experts who have never driven a Hyundai Genesis.

When talking about the Hyundai Tau V8, it is specifically designed to run on regular or premium (or in-between), and advertised as getting better HP with the higher octane fuel. This is documented in the owners manual and in other Hyundai publications.

Regarding your pre-paid oil changes, could you just pay the difference to upgrade to synthetic? Most dealers have it. At the very least, I would ask about synthetic blend.

 

[joeferrer]

Forgot to ask how much mph are you getting? In Miami city driving I get about 15mpg on the highway however I was getting 41-45 going 60-65mp on 1500-1700 rpm

 

[Mark_888]

Forgot to ask how much mph are you getting? In Miami city driving I get about 15mpg on the highway however I was getting 41-45 going 60-65mp on 1500-1700 rpm

The MPG calculator on the dash is not accurate, unless you drive 100 miles or more at one time. Even then, it is usually about 1 MPG over the actual mileage. There is no way you can get 41 MPG driving a Genesis sedan on a level surface at 60-65 MPH.

 

[joeferrer]

Well that's what I got while driving for 30 straight minutes on the highway.

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[Mark_888]

Well that's what I got while driving for 30 straight minutes on the highway.

The MPG calculator on the dash is not accurate. Sometimes it starts out at up to 99 MPG right after a fill-up or hitting the reset button. I have been on this forum for more than 8 years, and no one has reported more than about 34 MPG on a flat surface over a long distance (but I don't even think those numbers are accurate). The Genesis does coast well, so on hilly terrain, it is sometimes possible to get a higher than normal MPG.

Maybe you have tires that are different than the OEM size, or your on-board MPG calculator is not working correctly, or you are using jet fuel (and have modified your engine to use it)?

 

[landtuna]

The MPG calculator on the dash is not accurate, unless you drive 100 miles or more at one time. Even then, it is usually about 1 MPG over the actual mileage. There is no way you can get 41 MPG driving a Genesis sedan on a level surface at 60-65 MPH.

It isn't a matter of accuracy but rather how the math works. If you pay close attention to the MPG calculation immediately after filling your tank you will notice it starts out very low and gradually increases as the miles pile up. This is normal. The MPG number is calculated by dividing miles driven by fuel used and the more miles and fuel used the more accurate the average MPG.

The very best average highway mileage the Genesis 3.8 gets is around 30. I have gotten a corrected 28 in my R-spec but that is being real easy on the skinny pedal on relatively level ground. Obviously keeping the tires properly inflated, the air filter clean and a low viscosity motor oil in the engine is a big part of this.

 

[Mark_888]

It isn't a matter of accuracy but rather how the math works. If you pay close attention to the MPG calculation immediately after filling your tank you will notice it starts out very low and gradually increases as the miles pile up.

That's true because after you fill up, you start out driving slow (city driving mode) until you get a chance to get back on the highway. Then when you get to the highway, you burn a lot of gas in the process of accelerating to highway speed.

If one is already driving at highway speed, and hits the "reset" button, the MPG usually starts higher than normal, and goes back down as it averages out. One time when I was coasting down a long steep mountain road, I hit the reset button and the first MPG reading was 99 MPG. Typically on a flat highway, the first reading after hitting the reset button is in the high 30's or 40's, but goes back down quickly.

 

[joeferrer]

I wanted to test it out so what I did was I reset it for city driving drive for 40mins got about 15mpg. I hit the highway once I was hitting 60 I reset it and for the next 30 mins I went a consistent 60-65 and got 41-45mpg trust me I was just as shocked idk why or how I got this average. I do have a v6 but I thought the best I'd get would be 30-31 but somehow I'm getting 41-45mpg on the highway.

 

[landtuna]

I wanted to test it out so what I did was I reset it for city driving drive for 40mins got about 15mpg. I hit the highway once I was hitting 60 I reset it and for the next 30 mins I went a consistent 60-65 and got 41-45mpg trust me I was just as shocked idk why or how I got this average. I do have a v6 but I thought the best I'd get would be 30-31 but somehow I'm getting 41-45mpg on the highway.

There are two different MPG measurements on my R-spec (not sure about your 3.8). The "real time" measurement is a calculated number based upon engine vacuum and current speed (actually distance traveled). The less throttle (probably as measured by the mass airflow sensor) the more vacuum and the greater the mileage indication. This is your instantaneous MPG but is not very accurate and does not give an average over distance travelled.

The other measurement is "true" MPG as earlier described (distance travelled divided by fuel used) and is much more accurate. But it is only as accurate as both the odometer and fuel measurement are. If either or both of these are off so your mileage will be.

The most accurate measurement would be using a GPS. Set to zero when you fill your tank then take the miles travelled and divide by the total fuel used the next time you fill up. Using this method I really doubt you will find those magic 40+ numbers.

 

[henryb]

I recently got 34MPG on a long steady trip at 70MPH on cruise most of the time. I was very happy with that, 2012 3.8 liter. Around town I am getting 16 to 19 depending on how I drive.....number of stops etc. It's not possible to get 40+ MPG on the 3.8 liter ....maybe all down hill? Strange. I use mid grade gas.

 

[Ragnar]

Face it guys the best way to calculate your avg.milage is it the old fashioned way, after filing up divide the gallons bought to the miles driven.
Get out your pencils and paper😏