Premium in the 5.0

[HughH]

I don't own a Hyundai yet, possibly the R-Spec next year when the lease on my present Lexus expires.

I can't remember how long it's been since I used high octane gas in any of my cars. The last 3 cars have been a BMW 330i; a Lexus GS300 and and the present GS350.

Call me cheap, I just don't see any reason to give the big oil corporations more money than what we're giving them now.

BTW - I usually fill-up at either Costco or Sam's and have yet to get a bad tank-full. Their gas uses the same detergent mandated by law to clean the injectors.

The last time I ever had injector problem was with a 1974 Volvo 144 while stationed in Ankara, Turkey ('75-77). At that time, they did not use any detergent in their gas. I understand they do now.

So, use whatever you want...it's your dime.

 

[nadel]

i run only 99% quiktrip hightest rated at 93 octane, so i have no reference for you using regular gas.

 

[cnote]

The dealer filled it up with 87 but I am going to run 93 going forward.

 

[EXBMWGUY]

Although I have been a pretty consistent user of premium gas in the R-Spec, I've run a couple of tankfuls each of Shell and BP 87, as well as Kwik Trip 89, all with very good results. This engine was definitely designed to run on regular gas, even if it might give up 9-10 hp at the top end. Given a choice, I will again preach high quality fuel (top tier or BP) over just a high octane number.

 

[HughH]

Although I have been a pretty consistent user of premium gas in the R-Spec, I've run a couple of tankfuls each of Shell and BP 87, as well as Kwik Trip 89, all with very good results. This engine was definitely designed to run on regular gas, even if it might give up 9-10 hp at the top end. Given a choice, I will again preach high quality fuel (top tier or BP) over just a high octane number.

About 12-14 yrs ago, Car & Driver had a very informative TV show. One of their shows was exactly about this subject.

They tested a 911 Turbo and a Vette with a hot engine. They drained the gas tank and then refilled with regular and after draining the tank again, refilled with high octane. Results where better with the Porsche. The loss of hp was around 3-4. The Corvette lost around 7-8 hp. They gave kudos to German engineering and came to the following conclusion:

"If you intend to take your car to the track, by all means, use the highest octane gas you can find. Otherwise, you would be wasting your money by using the high octane gas for every day use of your car."

It's your car and your money...do whatever makes you feel good and enjoy yourself.

 

[jmatthew]

Curious to know what percentage of the new 5.0 owners run premium? Here in Missouri, unfortunately, "Premium" is 91 octane.

I've tried both and don't really notice a difference between the two in power. My driving habits vary so wildly (sometime lots of highway in a tank, sometimes none) that I can't yet get a good reading for how the MPG fares with the change. I've got a three hour drive and a trip back coming up - I may try to compare at that point.

1,300 miles and still smiling

What MPG are you getting? In mixed driving (mostly Hwy), I'm only getting 18MPG! Just wondering!!!

 

[Mark_888]

About 12-14 yrs ago, Car & Driver had a very informative TV show. One of their shows was exactly about this subject.

They tested a 911 Turbo and a Vette with a hot engine. They drained the gas tank and then refilled with regular and after draining the tank again, refilled with high octane. Results where better with the Porsche. The loss of hp was around 3-4. The Corvette lost around 7-8 hp. They gave kudos to German engineering and came to the following conclusion:

"If you intend to take your car to the track, by all means, use the highest octane gas you can find. Otherwise, you would be wasting your money by using the high octane gas for every day use of your car."

It's your car and your money...do whatever makes you feel good and enjoy yourself.

Did they test the difference in MPG? It may (or may not) have been enough to make up for all of the difference in cost between regular and premium, but it does make up for some of the difference.

Please don't tell me that the cars go more HP with premium, but there was no difference in MPG. Please don't try and tell me that.

 

[Mark_888]

My research over the years concluded that premium gasoline has less BTU than regular, meaning there is more energy potential in regular. From time to time I compare Interstate gas mileage alternating tanks of regular and premium; and have always found better gas mileage on Interstates with regular. I realize that this is crude test, but it has always been consistent. Generally, the differential seems to be about 1.5 mpg. Interstate driving is usually light throttle where there is no detonation causing the ignition advance to be dialed back.

It depends on the car (engine). Some engines can take advantage of premium with better HP and/or MPG, and some engines cannot (and some may actually perform worse with higher octane).

I am pretty sure that the Genesis V8 engines do perform better (higher HP and/or MPG) with higher octane, especially since Hyundai advertises in the specs for the V8 that HP is increased by about 7 HP with premium. They also perform their EPA MPG testing with premium, so it would be in their advantage to use the gas that got the highest MPG in those tests.

 

[427435]

FWIW---------------with the exception of a couple of tanks, I'm just using Tier 1 E10 regular gas. Runs fine, My butt dyno can't tell the difference between 420 hp and 429 hp.

 

[Potty_Pants]

About 12-14 yrs ago, Car & Driver had a very informative TV show. One of their shows was exactly about this subject.

They tested a 911 Turbo and a Vette with a hot engine. They drained the gas tank and then refilled with regular and after draining the tank again, refilled with high octane. Results where better with the Porsche. The loss of hp was around 3-4. The Corvette lost around 7-8 hp. They gave kudos to German engineering and came to the following conclusion:

"If you intend to take your car to the track, by all means, use the highest octane gas you can find. Otherwise, you would be wasting your money by using the high octane gas for every day use of your car."

It's your car and your money...do whatever makes you feel good and enjoy yourself.

quite a long time ago... electronics / sensors have changed since then. I suspect they both had Fuel Injection and ODB2, electronic ignition ?...

Apples to oranges too... a V6 turbo vs NA V8.

would be nice to read the article if it can be located.

ppp

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[wd40]

Do you realize that modern cars are timed to burn a specific octane and that burning a higher than recommended octane is not only not beneficial, but could actually be causing you a disservice (lower hp, lower fuel economy, etc.)?

It's a myth oil companies have created that premium is "better" for all engines. It should only be used if recommended by the manufacturer.

There are many articles covering the myth of using premium unless mandated by the manufacturer. I've tried bot and don't notice any difference. Car runs fine on regular. Had a 2013 Mustang GT and the vehicle ran very well on regular. Don't waste your hard earned money.

 

[abraxas]

one of the appealing traits of the genesis r-spec is that you can fill it up with regular gas. I've been doing that since the first day I bought this car and it runs just fine.

 

[Mark_888]

There are many articles covering the myth of using premium unless mandated by the manufacturer. I've tried bot and don't notice any difference. Car runs fine on regular. Had a 2013 Mustang GT and the vehicle ran very well on regular. Don't waste your hard earned money.

Those articles are talking about engines which are not designed to run at higher HP with premium. However the Genesis V8 is designed to run at higher HP with premium (about 7 HP more). The fact that you don't notice any difference is not a scientific evaluation. Same applies to butt dyno's mentioned by others.

Yes, the Genesis V8 runs "fine" on regular, and I believe that the Genesis runs fine with the V6. I personally think the V8 is a waste of hard earned money (initial cost, insurance, poorer MPG), but I am not crazy enough to claim that the V6 gets the same HP as the V8.

 

[wd40]

Those articles are talking about engines which are not designed to run at higher HP with premium. However the Genesis V8 is designed to run at higher HP with premium (about 7 HP more). The fact that you don't notice any difference is not a scientific evaluation. Same applies to butt dyno's mentioned by others.

Yes, the Genesis V8 runs "fine" on regular, and I believe that the Genesis runs fine with the V6. I personally think the V8 is a waste of hard earned money (initial cost, insurance, poorer MPG), but I am not crazy enough to claim that the V6 gets the same HP as the V8.

Of course it is not a scientific evaluation and it was not meant to be scientific. I've not heard of anyone that routinely tracks or races their R-spec (unlike several Corvette owners I know) and the seven to nine HP difference would hardly make any difference in lap or quarter mile time. I drove the v-6 and I much prefer the v-8; smoother, more low end and just plain giddy-up. My car runs very well on regular and there are plenty of legitimate well documented articles that tell you running premium is not only not necessary but a waste of money. The R spec is not a 911 Turbo S.

 

[shagnat]

Do you realize that modern cars are timed to burn a specific octane and that burning a higher than recommended octane is not only not beneficial, but could actually be causing you a disservice (lower hp, lower fuel economy, etc.)?

It's a myth oil companies have created that premium is "better" for all engines. It should only be used if recommended by the manufacturer.

Glad you told him. Some peeps just don't wanna' get it.

A "friend" of mine just bout a new Mercedes GLK-350 and it states very plainly to use "premium" only. He said he wasn't buying premium due to the price difference..... I refused to show him on paper how little extra that would cost over a year....... Now, why in the world would someone buy a $50k mercedes and cheap out on the gas???!!! Because he's a dumb@ss retired banker with no common sense at all.......... imagine that!

 

[Mark_888]

Glad you told him. Some peeps just don't wanna' get it.

A "friend" of mine just bout a new Mercedes GLK-350 and it states very plainly to use "premium" only. He said he wasn't buying premium due to the price difference..... I refused to show him on paper how little extra that would cost over a year....... Now, why in the world would someone buy a $50k mercedes and cheap out on the gas???!!! Because he's a dumb@ss retired banker with no common sense at all.......... imagine that!

Some engines like the Genesis V8 are designed to use either regular or premium, and to get better HP and/or MPG with the higher octane fuel. Hyundai specifies a different HP rating for both regular and premium fuel (difference is about 7-9 HP). Many engines are designed to only run regular, or to only run premium, but the Genesis V8 is not one of those.

 

[JasTheAce]

Glad you told him. Some peeps just don't wanna' get it.

A "friend" of mine just bout a new Mercedes GLK-350 and it states very plainly to use "premium" only. He said he wasn't buying premium due to the price difference..... I refused to show him on paper how little extra that would cost over a year....... Now, why in the world would someone buy a $50k mercedes and cheap out on the gas???!!! Because he's a dumb@ss retired banker with no common sense at all.......... imagine that!

Actually the glk is an odd car. The 2011 we have was filled with only shell 93 and in the winter it wouldn't start. The dealer stated to use 89, which we have done since. Generally if the car isn't knocking you are fine. I'll second the top tier gas over octane rating however as I can tell a difference when using poor quality gas.

 

[Mark63021]

I've never used anything but 93 octane in mine. For as infrequently as I fill up, the couple extra buck it costs for a tank of premium is worth every bit of the "buying the best" feeling I get from choosing it.

 

[Mark_888]

Actually the glk is an odd car. The 2011 we have was filled with only shell 93 and in the winter it wouldn't start.

That's not totally surprising, since regular burns hotter than premium. If I had an engine designed to use either regular or premium, I would definitely be less inclined to use premium in very cold weather.

 

[jmo51]

Premium fuel only. Nothing less that 91.