Gas MPG

[EdP]

You'd get better gas mileage with higher octane fuel. Premium from a good station like Shell also has cleaners that'll keep carbon from building up on your injectors and intake valves.

Are you aware of how gas is refined and shipped? Difference between brands? OK. the difference is in the advertising, not the product.

All gasoline is refined to the same specifications for either regular or premium grade and goes into a pipeline or tanker to take it to a port tank farm. The delivery truck takes on the proper octane and if it is a Top Tier they add the additives in the tanker to be mixed. Then he makes a delivery and the same exact product may go to Shell, Marathon, or any of the stations using Top Tier.

 

[BillZ]

In real world comparison of mileage on the GV80 3.5T posted on this forum, it has been demonstrated that there is no mileage improvement with premium gas. The most important issue is using top tier gas (not for mileage but for engine health). You can choose to spend the extra on premium top tier if it makes you feel better, but no one has shown any advantage using it over regular top tier.

 

[Jhon]

Everything I have ever read says that Octane has very little to do with gas mileage. It does help a little, but nothing really noticeable. google it. You might find one article for every 15 that says it does. That being said, I drive so little these days, I have no issue with putting premium in my car, and where I live, they don't sell 91 you have to get 93. But if I was driving 1,000 miles a week, I would probably use regular and if it ran just fine, I would keep using it.
The better brands have better additives which will help keep your engine clean.

 

[TCG]

See my signature banner below. I'm no pooch, but also don't drive like I stole it either.
And, Like Dale above, I only use regular!

You use regular and have no issues? Do you have the V6?

 

[BillZ]

You use regular and have no issues? Do you have the V6?

I am attaching a post from Speeder on this forum. He has been extremely helpful documenting mileage using Regular vs Premium. An updated chart he posted more recently showed the same. His charts speak for themselves, namely no benefit from Premium with respect to mileage. No owner has ever posted a problem or performance issue from using Regular gas; further, the owner's manual specifically states that the engine is designed to run on 87 octane although 91 is recommended for "maximum performance". I previously posted a Youtube video from Consumer Reports showing no performance difference using Premium over Regular in vehicles in which Premium is "recommended", but not "required". I'll say it again. If it makes you feel better to use Premium, go for it. I'll continue to save my money using top-tier Regular.

 

[koala]

Winter gas impacts fuel economy, too.

80% of the mileage on our GV80 is highway driving at a consistent speed, so our fuel economy is very consistent. In the summer, I usually get between 10 to 10.5 l / 100 km. This last 700+ km trip was 13.5 l / 100 km (17.4 mpg) at an average speed of 125 km/h (a touch under 78 mph).

 

[Crito]

I've consistently gotten 2-3 MPG better fuel economy with premium gas, in vehicles tuned to take advantage of the higher octane. All that matters when it comes to fuel economy is how far down you have to depress the accelerator. More power at a lower RPM means you don't have to push it down as far. It's plain common sense. Of course, if you constantly drive like a bat out of hell with the pedal to the metal, you're going to get the same lousy mileage regardless.

 

[BillZ]

I've consistently gotten 2-3 MPG better fuel economy with premium gas, in vehicles tuned to take advantage of the higher octane. All that matters when it comes to fuel economy is how far down you have to depress the accelerator. More power at a lower RPM means you don't have to push it down as far. It's plain common sense. Of course, if you constantly drive like a bat out of hell with the pedal to the metal, you're going to get the same lousy mileage regardless.

If you could undertake a similar test as was done by Speeder over a reasonable period of time with actual measurements of miles driven and gallons consumed, I would be interested to see if your impression of better mileage with premium in the GV80 would be confirmed. His results appeared very convincing and showed that if there was any mileage difference between regular and premium, it was regular that had the edge. Actual data is the real test. I'm not saying you are wrong, but the data he reported shows otherwise.

 

[Crito]

The majority aren't always right. I was reading another thread here where everyone thought 0W-30 oil turns to zero weight when it's -15 degrees outside. Only one guy got the answer right, 0W is a winter grade not a weight. It represents minimum flow rate in cold temps. 0W is not thinner than 5W at operating temp. Is it easier to pour honey out at a jar when it's freezing outside or when it's 100 degrees? Again, it's just common sense, everything gets THICKER as it gets colder, so I feel no need to prove it.

But I have posted a video showing I get 36 MPG using Premium, so if someone running 87 octane wants to prove me wrong, all you have to do is get the same mileage using cheap gas. You can't because you have to depress the pedal more to get moving than I do. And quite frankly I'm NEVER going to put low octane in my high compression vehicle. That's a no-no in my book even if direct injection lets people get away with it (there's no fuel in chamber during compression stoke).

EDIT: Oh and there is one more thing to mention... direct injection engines are notorious for carbon build-up on the intake valves. It's my understanding than in dual injection vehicles like ours the port injectors are used during warm up which cleans the valves. Because of knocking with low octane gas, your engine management computer may be switching to direct injection almost as soon as you start it. That means those valves won't get cleaned properly regardless of how many additives/cleaners are in your gas.

 

[Speeder]

EDIT: Oh and there is one more thing to mention... direct injection engines are notorious for carbon build-up on the intake valves. It's my understanding than in dual injection vehicles like ours the port injectors are used during warm up which cleans the valves. Because of knocking with low octane gas, your engine management computer may be switching to direct injection almost as soon as you start it. That means those valves won't get cleaned properly regardless of how many additives/cleaners are in your gas.

Check out the link I've included, it explains the new Smartstream fuel system and when the Port and Direct injectors are used. Sounds like the Port injectors are not only used for startup.

Smartstream - Hyundai Motor Group TECH

SmartstreamThe Ever-evolving World of Powertrain A car’s performance is said to be defined by its movement—run fast, run strong. But in recent years, se...

tech.hyundaimotorgroup.com

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[koala]

Check out the link I've included, it explains the new Smartstream fuel system and when the Port and Direct injectors are used. Sounds like the Port injectors are not only used for startup.

Smartstream - Hyundai Motor Group TECH

SmartstreamThe Ever-evolving World of Powertrain A car’s performance is said to be defined by its movement—run fast, run strong. But in recent years, se...

tech.hyundaimotorgroup.com

Crito is saying those who are running 87 likely aren't benefiting from port injection. It stands to reason if your ECU is detecting knock, it's going to simplify how it delivers fuel.

Just one more reason why running 87 in an engine with a 91 map is not ideal.

 

[EdP]

And quite frankly I'm NEVER going to put low octane in my high compression vehicle. That's a no-no in my book even if direct injection lets people get away with it (there's no fuel in chamber during compression stoke).

EDIT: Oh and there is one more thing to mention... direct injection engines are notorious for carbon build-up on the intake valves. It's my understanding than in dual injection vehicles like ours the port injectors are used during warm up which cleans the valves. Because of knocking with low octane gas, your engine management computer may be switching to direct injection almost as soon as you start it. That means those valves won't get cleaned properly regardless of how many additives/cleaners are in your gas.

What do you consider high compression? What about GDI engines designed to run on 87 octane.

Hyundai Genesis 3.8 V6 Engine - Problems, Specs, Reliability, HP, & More

Learn about the Hyundai Genesis 3.8 Lambda II engine. Hyundai 3.8 engine problems, reliability, specs, hp, & more. Genesis 3.8L V6.

tuningpro.co

Compression Ratio 10.4 : 1 (MPI), 11.5 : 1 (GDI)

 

[Speeder]

Crito is saying those who are running 87 likely aren't benefiting from port injection. It stands to reason if your ECU is detecting knock, it's going to simplify how it delivers fuel.

Just one more reason why running 87 in an engine with a 91 map is not ideal.

Knock is corrected by timing adjustments.

 

[koala]

Knock is corrected by timing adjustments.

Obviously

 

[Speeder]

Crito is saying those who are running 87 likely aren't benefiting from port injection. It stands to reason if your ECU is detecting knock, it's going to simplify how it delivers fuel.

Just one more reason why running 87 in an engine with a 91 map is not ideal.

Honestly, I don't think the ECU can detect the Octane rating of the gas I put in.

This is what my Manual says:

 

[Jhon]

Knock is corrected by timing adjustments.

Yes, and to my limited knowledge, that is all done on the go by the cars computer not a mechanic tuning your car for the type gas you used like they did in the olden days.
99% of every article I have read about Ocatain, says it has minor effect on mileage and performance.
As far as longevity of the engine, I don't know.
But using top tier gas which has better additives, is the best thing gas wise you can do for your engine.
That being said, I use top tier premium. Except for last month when I used about 20 gallons of left over mid grade gas I had purchased for my generator that I did not need as we got our power back before I used it up.

 

[EdP]

Yes, and to my limited knowledge, that is all done on the go by the cars computer not rather than a mechanic tuning your car for the type gas you used like they did in the olden days.
99% of every article I have raid about Ocatain, says it has minor effect on mileage and performance.
As far as longevity of the engine, I don't know.
But using top tier gas which has better additives, is the best thing gas wise you can do for your engine.
That being said, I use top tier premium. Except for last month when I used about 20 gallons of left over mid grade gas I had purchased for my generator that I did not need as we got our power back before I used it up.

If you used premium in the generator the lights would be brighter and the 6 o'clock news would have less politics.

 

[koala]

Honestly, I don't think the ECU can detect the Octane rating of the gas I put in.

This is what my Manual says:
View attachment 49663

Every engine with an ECU can detect octane

 

[Speeder]

Every engine with an ECU can detect octane

Really?

 

[koala]

Really?

Yes. Not in the sense that the ECU has some magical way to test the fuel and report a value for octane. What an ECU does is detect ping and then it can pull timing based on that. This is a roundabout way of saying it knows the octane of the fuel based on the parameters it is seeing.