Is there any benefits to premium gas on Hyundai Genesis 3.8 2015/2016

[classyobi]

Like the title said, Is their better mpg or overall performance boost with Hp/Torque?

 

[EdP]

Yes one big benefit, the oil company makes more profit. The 5.0 does have a bit better performance, but that engine was designed to use it.

 

[Mark_888]

I use mid-grade on my 1G Genesis V6, and it seems to run quieter, and a little bit better HP and MPG.

 

[AustinTX]

I tested this over four tanks of gas, and there is no discernible difference between 87 and 93 octane gas, other than a substantially higher price.

All my fill-ups are tracked on the Fuelly link in my signature.

 

[Mark_888]

I tested this over four tanks of gas, and there is no discernible difference between 87 and 93 octane gas, other than a substantially higher price.

I found that mid-grade actually got better gas mileage than premium on my V6. One can also do a custom blend of a mixture of regular and premium, like 2/3 and 1/3, or whatever. I make sure not to completely fill up the tank when blending the gas, so it sloshes around and mixes up more easily.

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Yes one big benefit, the oil company makes more profit. The 5.0 does have a bit better performance, but that engine was designed to use it.

Usually it is the retailer who makes the added profit on premium gas. More and more, the oil big oil companies are getting away from owning gas stations. Some pure refiners own their own stations, and also supply gas to other retailers (there are usually only a small number of refineries in any one city).

 

[silberma]

If a car is designed to run on regular gas, using premium gas will only hurt your bank balance. All gasolines have the same levels of energy content (BTU) however premium gas have additives to prevent pre-ignition at high compression ratios. So you get better performance because the engine has been tuned for this, but no better gas mileage. Furthermore if your car is designed to run on premium but does not knock on regular I use regular gas. The only exception is when is drive at higher speeds in the mountains and the demands on the engine are more severe.

 

[Mark_888]

If a car is designed to run on regular gas, using premium gas will only hurt your bank balance.

I have two comments on that:

1. Hyundai has in the past been known to push the envelope when it comes to gas, fuel mileage ratings, etc. They got in big trouble with the EPA on this a few years back. My guess is that they tune the engines to get maximum fuel mileage and HP, with a compression ratio that leaves very little room for error, and problems may occur when getting gas with maybe a tiny bit less octane than it should have. Also, over time, engines typically need slightly more octane than when new, in order to prevent detonation (pinging).

2. I would agree that premium is too much octane for the V6 to justify the cost. However, on my 1G V6, it does run quieter with better fuel mileage and HP when running mid-grade, or even slightly higher octane than regular (using a custom blend). So if anyone wants to know about whether to use something other than regular, then I would suggest they try it (with midgrade or a custom blend) and see how they like it, instead of just theoretical arguments that may be true for most engines, or older engines, but "may" not be applicable to the Genesis V6. I don't see what the issue is with trying a mid-grade gas for the V6.

 

[BlancaGenny]

I run mid-grade. Here, it is 89. 91 is the highest we get here because of altitude purposes. Numerous gas stations even have 85. I don't like putting the minimums in when it comes to my vehicles. For an extra 10-25 cents/gallon, it's worth it for me and it runs better.

 

[dougmcp]

I run mid-grade. Here, it is 89. 91 is the highest we get here because of altitude purposes. Numerous gas stations even have 85. I don't like putting the minimums in when it comes to my vehicles. For an extra 10-25 cents/gallon, it's worth it for me and it runs better.

85 octane gasoline is only available in high altitude states and is intended for carbureted engines only. The minimum you can/should run in a fuel injected or turbo engine is 87 octane. All cars today are equipped with knock sensors that constantly adjust timing to reduce knock.

 

[BillZ]

Forget wasting money on higher octane gas for the 6. But do spend the extra pennies if necessary to use top-tier gas.

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[silberma]

I have two comments on that:

1. Hyundai has in the past been known to push the envelope when it comes to gas, fuel mileage ratings, etc. They got in big trouble with the EPA on this a few years back. My guess is that they tune the engines to get maximum fuel mileage and HP, with a compression ratio that leaves very little room for error, and problems may occur when getting gas with maybe a tiny bit less octane than it should have. Also, over time, engines typically need slightly more octane than when new, in order to prevent detonation (pinging).

2. I would agree that premium is too much octane for the V6 to justify the cost. However, on my 1G V6, it does run quieter with better fuel mileage and HP when running mid-grade, or even slightly higher octane than regular (using a custom blend). So if anyone wants to know about whether to use something other than regular, then I would suggest they try it (with midgrade or a custom blend) and see how they like it, instead of just theoretical arguments that may be true for most engines, or older engines, but "may" not be applicable to the Genesis V6. I don't see what the issue is with trying a mid-grade gas for the V6.

Why would an engine need higher octane when it get older? Does the engine compression ratio mysteriously increase when it gets older requiring higher octane gas?

I run regular gas in my Infiniti as my driving style is not aggressive requiring premium gas. Also if the octane requirement are not met the knock sensors keep the engine out of trouble. I did not detect measurable differences in gas mileage between regular and premium gas.

 

[Mark_888]

Why would an engine need higher octane when it get older? Does the engine compression ratio mysteriously increase when it gets older requiring higher octane gas?

I run regular gas in my Infiniti as my driving style is not aggressive requiring premium gas. Also if the octane requirement are not met the knock sensors keep the engine out of trouble. I did not detect measurable differences in gas mileage between regular and premium gas.

First of all, the octane difference between regular and premium is probably to large to justify for an engine designed to run on regular (not talking about the Genesis 5.0 V8 which is designed to run on regular or premium with better performance on premium). That's why I only recommend using mid-grade, or a custom blend (of regular mixed with premium) with even lower octane than mid-grade.

I already told you some reasons why a Hyundai engine with a lot of miles on it may need a little more octane, because Hyundai is known to push the envelope when tuning cars for maximum gas mileage and HP.

I also mentioned that high mileage engines might benefit from more octane. Here is a quote that explains it:

"But as a car gets older, depending on how the car has been driven and cared for, it may need a higher-octane gasoline anytime between four and six years. That's because carbon deposits inside the cylinders raise the combustion ratio, which in turn raises the engine's octane rating. You may notice that your car operated fine on regular fuel when it was new, but pings on regular as it gets older. So, the higher-octane fuel is not something to pamper a new car with but rather help keep an older car running properly.

In addition, premium gasoline has some other selling points. Most premium gasolines have a higher-quality additive package put in at the refinery. The actual additives in a particular brand of gasoline are generally not disclosed by refiners. But usually they include detergents and other solvents that keep the carburetor and rest of the fuel system clean."
https://www.kbb.com/car-advice/articles/premium-gas-when-and-why/​

Not all regular gas is created equal, or may not be equal even from one refinery run to another at the same refinery, or because of the age of the gas, or because or wholesaler or retailer corruption.

In my own experience, with a mid-grade gas on my Genesis V6 with 63K miles, I get almost 1 MPG better mileage on the highway, and the engine is a bit quieter. It's not really possible to accurately measure city driving MPG, because no two trips are the same.

My advice is to stop theorizing about it, and try a mid-grade or equivalent custom blend, and see how it works for each Genesis V6 owner. If you don't think it helps, then go back to regular only. Clearly, IMO, 100% premium for the Genesis V6 is more octane than it can efficiently use, so don't even mention that option.

 

[1FstYota]

Believe it or not older engines does have a bit higher compression due to carbon build up on the top of the pistons, as for the fuel debate, its all about knock and what it can do for emissions. So if you use cheap fuel, knock sensors pick this up and reduce timing as needed and oh what else it adds a bit more fuel to cool the cylinder down.

Edit - saw Marks post just now, anyways if you want to go thru the trouble you can always setup an aftermarket ecu with IAT, Knock, wideband A/F and datalog the difference.

 

[BlancaGenny]

85 octane gasoline is only available in high altitude states and is intended for carbureted engines only. The minimum you can/should run in a fuel injected or turbo engine is 87 octane. All cars today are equipped with knock sensors that constantly adjust timing to reduce knock.

I have a side gig at the airport here in town and the rental vehicles all get 85... That's the only option. However, when an individual rents one, I'm sure the put in 87 at a regular gas station. The fluctuation of octane is no good for the motor. Imagine going from 91 to 85. Scary.

 

[EdP]

The fluctuation of octane is no good for the motor. Imagine going from 91 to 85. Scary.

Why? Can you please explain this? Once mixed in the tank it would be consistent going to the engine for that tank. Electronics are supposedly compensating. What am I missing"

 

[BlancaGenny]

Why? Can you please explain this? Once mixed in the tank it would be consistent going to the engine for that tank. Electronics are supposedly compensating. What am I missing"

One tank is not consistency.

There are loads of articles from people specifying why. If I go to the gas station, fill up on 87, run that tank dry, and fill up with 91, this is good. However, if I run my 91 tank dry and fill up with 87, the ecu has to compensate for the lower octane fuel. What I'm getting at is consistency. If you buy a car and put 87 in it, continue to put 87 in it. If you start out with 91, continue with 91. Since cars are not downward compatible, a car requiring 91 octane will run great with 95 or even 98 octane. The same cannot be said with cars requiring 91 and one puts 89 or 87 in. Sure, the computer can compensate but at what cost? Pre-ignition? Knocking?

Consistently putting one octane rating in your gas tank is the best for the car overall. The computer does not have to recognize a huge difference from different 91 octane gas suppliers (Mobil, Exxon, BP, etc.) The computer does, however, have to compensate drastically in order to detect the lower octane ratings, even in only from 91 to 89. This brings about pre-ignition and knocking and rough idling and so on.

 

[EdP]

One tank is not consistency.

There are loads of articles from people specifying why. If I go to the gas station, fill up on 87, run that tank dry, and fill up with 91, this is good. However, if I run my 91 tank dry and fill up with 87, the ecu has to compensate for the lower octane fuel. What I'm getting at is consistency. If you buy a car and put 87 in it, continue to put 87 in it. If you start out with 91, continue with 91. Since cars are not downward compatible, a car requiring 91 octane will run great with 95 or even 98 octane. The same cannot be said with cars requiring 91 and one puts 89 or 87 in..

OK, that makes sense to never go below what the engine was designed for even it you "can" do it.

 

[TroyK]

The published ratings of the 3.8L v6 are based on using 93 octane. So, I presume there'd be a slight drop in hp/torque when using fuel with a lower octane.

 

[Mark_888]

The published ratings of the 3.8L v6 are based on using 93 octane. So, I presume there'd be a slight drop in hp/torque when using fuel with a lower octane.

Are you talking about EPA mileage ratings, or something else?

For 2016, the Hyundai Genesis 3.8L sedan was EPA tested with regular. The 3.8L coupe was tested with premium. The 5.0 sedan was tested with premium.
https://www.fueleconomy.gov/feg/bymodel/2016_Hyundai_Genesis.shtml
It is interesting that the 3.8L Hyundai Genesis Coupe was tested with premium.

For 2018, the Genesis G80 3.8L sedan was EPA tested with regular. The 3.3L TT and 5,0 were tested with premium.
https://www.fueleconomy.gov/feg/bymodel/2018_Genesis_G80.shtml

 

[TroyK]

Are you talking about EPA mileage ratings, or something else?

For 2016, the Hyundai Genesis 3.8L sedan was EPA tested with regular. The 3.8L coupe was tested with premium. The 5.0 sedan was tested with premium.
https://www.fueleconomy.gov/feg/bymodel/2016_Hyundai_Genesis.shtml
It is interesting that the 3.8L Hyundai Genesis Coupe was tested with premium.

For 2018, the Genesis G80 3.8L sedan was EPA tested with regular. The 3.3L TT and 5,0 were tested with premium.
https://www.fueleconomy.gov/feg/bymodel/2018_Genesis_G80.shtml

hp/torque ratings...