Super Unleaded test compared to Regular Unleaded:

[Mark_888]

Even though one of these guys just died, I think the Car Talk guys are more credible on this subject.

The fact that one of them recently died tells you everything you need to know. Their knowledge of engines is/was out of date. The advances in engine technology, mostly as the result of on-board computers, is no less significant in engines than in other technologies.

Hyundai specifically states that the V8 gets better HP with premium gas. And they do EPA mileage tests with premium, which strongly suggests it gets better MPG with premium (unless they are stupid).

 

[Midnightsun]

The fact that one of them recently died tells you everything you need to know. Their knowledge of engines is/was out of date. The advances in engine technology, mostly as the result of on-board computers, is no less significant in engines than in other technologies.

Hyundai specifically states that the V8 gets better HP with premium gas. And they do EPA mileage tests with premium, which strongly suggests it gets better MPG with premium (unless they are stupid).

This is also the case for the V6 however they do the tests with regular. Where's the logic?

 

[PMCErnie]

The fact that one of them recently died tells you everything you need to know. Their knowledge of engines is/was out of date. The advances in engine technology, mostly as the result of on-board computers, is no less significant in engines than in other technologies.

Hyundai specifically states that the V8 gets better HP with premium gas. And they do EPA mileage tests with premium, which strongly suggests it gets better MPG with premium (unless they are stupid).

Sad that you would besmirch Car Talk Tom's memory. Is Consumer Reports stupid and out of date too ? They say don't bother with premium fuel unless your engine requires it to prevent knocking. Genesis engines do not require it.

http://consumerreports.org/cro/magazine/2012/08/debunking-fuel-economy-myths/index.htm

http://m.csmonitor.com/Business/In-...umer-Reports-takes-on-alleged-gas-saving-tips

 

[QCTLG]

I did a test years ago with my V8 2009 and got better results using Regular over Supreme gas.

I travel often from Montreal to Edmunston N.B. (550KM/342mi)

On 6 trips (3 with Supreme and 3 with Regular)
Driving speed on cruise control @ 110KMPH/68MPH I avg'd...
Regular 33.13MPG
Supreme 31.36MPG

I use nothing but Regular and see no reason to use Supreme gas

 

[scottdk]

sub'd. This is awesome because nobody believes I get better MPG from Premium even though I have the data to back it up.

Keep up the good work!

+1 Agreed. Maybe this doesn't apply to all cars that require premium fuel, but my V8 can use regular or premium, but makes an extra 7hp using premium in addition to my observed increased fuel economy. It may be not a huge increase, but it's enough to wash the extra cost of premium and than some, especially with the current $2.40/gallon for premium in the Twin Cities.

 

[Mark_888]

Sad that you would besmirch Car Talk Tom's memory. Is Consumer Reports stupid and out of date too ? They say don't bother with premium fuel unless your engine requires it to prevent knocking. Genesis engines do not require it.

http://consumerreports.org/cro/magazine/2012/08/debunking-fuel-economy-myths/index.htm

http://m.csmonitor.com/Business/In-...umer-Reports-takes-on-alleged-gas-saving-tips

In the early days of their radio show, I listed to them quite often on NPR. But it was mainly a comedy show. It has been many, many years since they actual worked on cars themselves.

If Consumer Reports wants to do a MPG test with regular vs premium gas on the Genesis V8, then I will believe their results. I am not interested in their generalizations. Also, I never said whether the extra MPG and HP with premium for the Genesis V8 is worth the extra price of premium gas, only that with premium one should get better MPG and/or more HP. Whether it is worth it is up to each owner. I don't like Consumer Reports making value judgments for me, I prefer they just give me the facts and let me decide.

 

[Mark_888]

This is also the case for the V6 however they do the tests with regular. Where's the logic?

I would assume that buyers of the V6 not as interested in the increased HP as V8 owners. Doing the EPA mileage test with premium puts the V6 at a disadvantage on cost of ownership compared to some other cars, and the typical V6 owner may be more cost conscious than a V8 owner. These kinds of decisions are what marketing is all about.

 

[jimb100]

Isn't the real question the amount of energy contained in a gallon of 91 octane vs a gallon of 87?

I would think today's Genesis would be able to wring all the energy from the gas there is to be had. Certainly ethanol laced gas has less energy than gas without it. But apples to apples there must be tests done that show the amount of energy in premium vs regular.

Wouldn't that be the scientific way to decide the issue?

 

[Mark_888]

Isn't the real question the amount of energy contained in a gallon of 91 octane vs a gallon of 87?

I would think today's Genesis would be able to wring all the energy from the gas there is to be had. Certainly ethanol laced gas has less energy than gas without it. But apples to apples there must be tests done that show the amount of energy in premium vs regular.

Wouldn't that be the scientific way to decide the issue?

One of the "problems" is that not all engines have computer variable adjustments that enable them to utilize all that extra energy. Most older cars do not, and that is why there are so many outdated recommendations floating around. The Genesis V8 does have that capability, which is easy to measure using the on-board MPG computer (even if it is not absolutely correct, it will be correct relative to using regular vs premium).

 

[Midnightsun]

One of the "problems" is that not all engines have computer variable adjustments that enable them to utilize all that extra energy. Most older cars do not, and that is why there are so many outdated recommendations floating around. The Genesis V8 does have that capability, which is easy to measure using the on-board MPG computer (even if it is not absolutely correct, it will be correct relative to using regular vs premium).

There's your problem, Premium has no extra energy whatsoever, only difference in layman's terms is premium is concocted to reduce the volatility of the mixture. You are paying extra for premium because it takes additional refining steps to reduce the volatility, not because it is more powerful or any better. Only engines today that do require premium are of the turbo variety. Preignition sensors are quite old and I would venture to say anything 10+ years old will automatically adjust to the fuel used.

Look at it this way, most are suckers for advertising strategies and if they sold gasoline today as "gas" and "anti pre ignition gas" we would never have had the premium vs regular debate. It really is amazing what a word can put into peoples minds.

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[homeofstone]

Premium Extra energy? Not really. I posted this link much earlier but as I read recent post It appears that some people here did not read it. It explains octane and knocking etc.

http://www.economist.com/blogs/babbage/2012/09/octane-ratings

 

[DavidA5913]

Interesting article. Thanks for the repost.

 

[PMCErnie]

In the early days of their radio show, I listed to them quite often on NPR. But it was mainly a comedy show. It has been many, many years since they actual worked on cars themselves.

If Consumer Reports wants to do a MPG test with regular vs premium gas on the Genesis V8, then I will believe their results. I am not interested in their generalizations. Also, I never said whether the extra MPG and HP with premium for the Genesis V8 is worth the extra price of premium gas, only that with premium one should get better MPG and/or more HP. Whether it is worth it is up to each owner. I don't like Consumer Reports making value judgments for me, I prefer they just give me the facts and let me decide.

All the experts in "the whole wide world" say that using premium gas unnecessarily will cost you more money per mile than regular. That is what we are debating here. Those car owners who want to reduce their 0-60 time by .1 seconds are certainly welcome to pay more for that privilege. I doubt that you put premium gas in your car so, obviously, you completely agree with me on this point. Premium gas buyers, assuming the current cost differential, will always pay more to drive from point A to B.

 

[powerslide]

It seems this discussion is purely in regards to fuel efficiency? You guys are all driving the wrong car if that is your primary concern. Forget mpg. What about performance? In many cars, you get better acceleration with premium. When the computer/knock sensors compensate for lower octane fuel, it typically retards the timing, usually resulting in less HP. I know my previous car had noticeably better acceleration with premium. I haven't tested it enough to say one way or another with my V6 AWD.

 

[amartz]

I would assume that buyers of the V6 not as interested in the increased HP as V8 owners.

Now why in the world would you assume that? Since us V6 owners are at a horsepower disadvantage, I'd say we'd be *more* interested in increased HP than V8 owners, whom already have enough horsepower. (Relatively speaking, of course.)

 

[upsbroke]

Just a thought and maybe it's been said before. I see that some of the gas stations sell premium that doesn't contain ethanol. Could the lack of ethanol explain the added fuel economy that some are getting?
I only have a V6 but have noticed that once I started using fuel without alcohol, my mileage seemed to go from 27ish to 30+ish as indicated by the car's mfd.

 

[Midnightsun]

Just a thought and maybe it's been said before. I see that some of the gas stations sell premium that doesn't contain ethanol. Could the lack of ethanol explain the added fuel economy that some are getting?
I only have a V6 but have noticed that once I started using fuel without alcohol, my mileage seemed to go from 27ish to 30+ish as indicated by the car's mfd.

Any gas with ethanol is going to reduce milage substantially therefore any tests done with ethanol or non ethanol in the same will not give you the real picture.

A good example here is the Premium they sell at Shell stations in Canada. The regular and midgrade "may" contain up to 10% ethanol and the premium contains no ethanol. (This is what it says on the pumps) How are you supposed to test things when it says may contain?

Bottom line is if you really are interested in getting more milage out of every fill up you just need to find a station that sells regular with no ethanol mixed in.

 

[Alwaysforward]

For this test it is with 10% ethanol across all fuel levels.

 

[Alwaysforward]

It seems this discussion is purely in regards to fuel efficiency? You guys are all driving the wrong car if that is your primary concern.

I am driving the right car. I don't care about fuel economy. I am simply interested in seeing if there is an added benefit using Super Unleaded -vs- Regular Unleaded.

I gave fuel economy up when I traded in my 2002 Honda Civic SI which got 30mpg over the past 10 years...

 

[EXBMWGUY]

I am driving the right car. I don't car about fuel economy. I am simply interested in seeing if there is an added benefit using Super Unleaded -vs- Regular Unleaded.



I gave fuel economy up when I traded in my 2002 Honda Civic SI which got 30mpg over the past 10 years...

^ Yes!