Regular vs. Premium Unleaded Gasoline.

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Originally Posted By: SteveSRT8
Think CHICKEN WINGS! Used to be discarded for soup use, now expensive as all get out...


Just like sandwiches. Back in the day,you were given a sandwich by your parents if you were being punished,haha. Sandwiches were basically "slumming it" per se meal-wise. Now a sandwich is considered gourmet! $10+ dollars for some cheap coldcuts and bread? Good lord!
 
Definitely use premium if your car requires it. If it does and you go cheap and put in regular,you'll get a very unpleasant surprise when you put your foot in it (pinging).
 
Originally Posted By: Shannow
ypw makes some really good points, and it's not the gas companies screwing us, as he says...you need to shift stuff.

Silly analogy, but look at the different prices of different cuts of animal, offal etc. etc.

Lamb shanks I used to buy for 50c, then some classy places in Sydney started "rustic" cooking, slow cooked braised shanks...formerly poor man's food...now they are $4-5 each. More people will pay more for them.

There isn't much local lamb here in California. Tons of farmland. Cows as far as the eye can see, but hardly a blip when it comes to raising lamb. Yet walk into nearly any market, and the lamb is almost always going to be from Australia or NZ. I don't think it's because it can't be done, but because specialization in that particular commodity rules. We have something similar these days with the production of Group III base oils. Now fuel doesn't seem to be something that's specialized to that degree. It's used everywhere in the world, and it's produced everywhere in the world, where it takes a relatively short trip via ship or pipeline.

But as far as vehicle fuel goes, I don't doubt that oil refiners would love to make as much high octane fuel as they could, if there was a market for it and they could actually do it. But the nature of the beast is that you've got what you've got - which is limited by technology and the inherent properties of the raw material. Storing liquid fuel long term isn't going to make you any money, and your commodity is going to degrade if you don't get it out to the consumer quickly.

I could use some lengua right about now.
 
Originally Posted By: Peted


Ok. Gas is not food.

Secondly, most posters in this thread have experiences that tend to state otherwise. That being, even if a vehicle recommends 87 in the manual, the vehicle will run better on 93.


Not to be a smartbutt, but . . . Most posters in this thread have experiences that tend to state otherwise. Go ahead and add me to that list: zero difference in fuel economy or performance on a Ford Explorer with 4.0L OHV V6 (compression ratio 9.0:1) between Shell 87 & 93 octane. At such a compression ratio, the engine is normally not close to knocking, so a more knock-resistant fuel offers no performance advantage.
 
I recall reading a while ago that straight cut gas was about 60 octane. Knowing nothing about gasoline distillation and formulating gas blends and engine design--how un powerful would an engine for such a low octane gas be?

Or put slightly different, how much energy (or waste of a barrel of crude) is it to make high test?
 
Originally Posted By: SteveSRT8
Think CHICKEN WINGS! Used to be discarded for soup use, now expensive as all get out...

When I was a kid, I always had my pick at family dinners. I'd be the only one who'd touch wings or necks on turkeys or chickens. Everyone thought I was nuts. And yes, now people pay a fortune for wings.
 
Originally Posted By: AP9
Originally Posted By: Peted
Secondly, most posters in this thread have experiences that tend to state otherwise. That being, even if a vehicle recommends 87 in the manual, the vehicle will run better on 93.


Not to be a smartbutt, but . . . Most posters in this thread have experiences that tend to state otherwise. Go ahead and add me to that list: zero difference in fuel economy or performance on a Ford Explorer with 4.0L OHV V6 (compression ratio 9.0:1) between Shell 87 & 93 octane. At such a compression ratio, the engine is normally not close to knocking, so a more knock-resistant fuel offers no performance advantage.


I think Peted's statement is more correct if "will" is changed to "may". Even if a vehicle recommends 87, it MAY run better on 93. Some folks in this thread are speaking in absolute terms, and there are too many variables to do that accurately.

AP9, to your Explorer's engine, there's more to knocking than only the compression ratio. Ignition timing also plays a part. My Oldsmobile's V-8 engine (8.0:1 compression) would knock if I had the timing advanced too far. I'd say that it's likely that your Explorer automatically advances and retards timing, and that the maximum advance and maximum retard are set in the computer. It should be possible for your V-6 to knock on 87, if the timing were to be advanced that far. And if that were true, then it should also be possible for your V-6 to experience better performance on 93 octane.

Now, you've said that it doesn't. If it truly doesn't, then there's at least one explanation for that: your computer cannot advance the timing far enough to achieve that better performance on 93 octane. There's a direct correlation here with the aftermarket. You know those aftermarket tuning chips, the ones that often say that premium fuel is required? They're not increasing the compression ratio in the engine, or doing anything physical to the engine at all. They're simply advancing the timing beyond what the factory computer is capable of doing, thus unlocking the potential of a higher octane fuel.

So here again, because a vehicle's programming depends entirely on proprietary code written by the OEM, an accurate blanket statement cannot me made that says that a car either WILL or CANNOT run better on 93 if it recommends 87. The most correct answer is, "it depends". It depends on how that vehicle's software is written and how much timing advance is allowed in the computer.
 
With later model vehicles, how well a gasoline engine runs, be it on recommended 85 to 93 octane fuels can be mostly affected by how the valve and ignition timing perimeters have been programed into the electronic management system. Keep in mind that engine management systems have plus or minus tolerances as well as individual mechanical and electronic components. This is something that can cause two identical vehicles to get noticeably different fuel economy with everything else being equal.
 
Originally Posted By: stchman
Originally Posted By: Peted
Originally Posted By: stchman
I had a discussion with someone the other day and we got on the topic of 87 vs. 93 octane gas.

He said that he uses premium in all his cars as the engine will last longer. What a bunch of [censored].

I told that if the manual does not state to use premium, then its use is at best a waste of money.

He said that his cars "feel" better when they run premium. Sounds like the placebo effect has kicked in.

A few months ago I tried running a couple of tanks of 93 in my Silverado and guess what, no change in mileage or power feel. All I did was waste ~$7 a tank.

He did not want to believe me that octane is just a combustion inhibitor. Oh well.


Sad to say, but You're in the wrong. I have your twin truck and 93 definitely makes a difference. Smoother idle, slightly better mpg .5-1, over all a slightly better sounding/running engine, a small difference but a difference none the less. You most likely can't notice small fluctuations in the engine. Some are able to, some are not. Or because you are so set on your bias, it inhibits you to notice any difference at all..


I am going to assume your Sierra has the 5.3L engine, the 6.2L engine requires 91 octane.

The ability to "feel" what you're speaking of is called the placebo effect. Smoother idle, better sound,

After running 2 tanks of 93 in my Silverado, the gas mileage was approximately the same on 87. Even if you get the phantom 0.5MPG, the MPG gain is not worth the extra cost.

Bias?!! There are MANY studies that show if your vehicle does not require premium, running premium is a waste of money. If you wish to run premium in your truck that does not require it, go right ahead, your choice.


I know perfectly well what the placebo effect is.

We'll just have to agree to disagree.

Maybe the reason I notice benefits is because I only use Shell 93 'V-Power'. A high quality premium grade, not just any run of the mill premium gasoline.

All of my vehicles have always ran better on premium over 87. It is what it is.
 
Originally Posted By: Hokiefyd
Originally Posted By: AP9
Originally Posted By: Peted
Secondly, most posters in this thread have experiences that tend to state otherwise. That being, even if a vehicle recommends 87 in the manual, the vehicle will run better on 93.


Not to be a smartbutt, but . . . Most posters in this thread have experiences that tend to state otherwise. Go ahead and add me to that list: zero difference in fuel economy or performance on a Ford Explorer with 4.0L OHV V6 (compression ratio 9.0:1) between Shell 87 & 93 octane. At such a compression ratio, the engine is normally not close to knocking, so a more knock-resistant fuel offers no performance advantage.


I think Peted's statement is more correct if "will" is changed to "may". Even if a vehicle recommends 87, it MAY run better on 93. Some folks in this thread are speaking in absolute terms, and there are too many variables to do that accurately.


Hah, Yes, my mistake! May is a much better way of putting it. Thank you!
 
Originally Posted By: AP9
Originally Posted By: Peted


Ok. Gas is not food.

Secondly, most posters in this thread have experiences that tend to state otherwise. That being, even if a vehicle recommends 87 in the manual, the vehicle will run better on 93.


Not to be a smartbutt, but . . . Most posters in this thread have experiences that tend to state otherwise. Go ahead and add me to that list: zero difference in fuel economy or performance on a Ford Explorer with 4.0L OHV V6 (compression ratio 9.0:1) between Shell 87 & 93 octane. At such a compression ratio, the engine is normally not close to knocking, so a more knock-resistant fuel offers no performance advantage.


Okay, I went and added you to the 'list'. I counted all the posters who have used both 87/premium with cars that did not require premium.

7 posters state no difference/worse performance on premium and 13 posters stated an improvement. Nearly twice as many.

The numbers don't lie.
smirk.gif
 
Originally Posted By: Hokiefyd
Originally Posted By: AP9
Originally Posted By: Peted
Secondly, most posters in this thread have experiences that tend to state otherwise. That being, even if a vehicle recommends 87 in the manual, the vehicle will run better on 93.


Not to be a smartbutt, but . . . Most posters in this thread have experiences that tend to state otherwise. Go ahead and add me to that list: zero difference in fuel economy or performance on a Ford Explorer with 4.0L OHV V6 (compression ratio 9.0:1) between Shell 87 & 93 octane. At such a compression ratio, the engine is normally not close to knocking, so a more knock-resistant fuel offers no performance advantage.


I think Peted's statement is more correct if "will" is changed to "may". Even if a vehicle recommends 87, it MAY run better on 93. Some folks in this thread are speaking in absolute terms, and there are too many variables to do that accurately.

AP9, to your Explorer's engine, there's more to knocking than only the compression ratio. Ignition timing also plays a part. My Oldsmobile's V-8 engine (8.0:1 compression) would knock if I had the timing advanced too far. I'd say that it's likely that your Explorer automatically advances and retards timing, and that the maximum advance and maximum retard are set in the computer. It should be possible for your V-6 to knock on 87, if the timing were to be advanced that far. And if that were true, then it should also be possible for your V-6 to experience better performance on 93 octane.

Now, you've said that it doesn't. If it truly doesn't, then there's at least one explanation for that: your computer cannot advance the timing far enough to achieve that better performance on 93 octane. There's a direct correlation here with the aftermarket. You know those aftermarket tuning chips, the ones that often say that premium fuel is required? They're not increasing the compression ratio in the engine, or doing anything physical to the engine at all. They're simply advancing the timing beyond what the factory computer is capable of doing, thus unlocking the potential of a higher octane fuel.

So here again, because a vehicle's programming depends entirely on proprietary code written by the OEM, an accurate blanket statement cannot me made that says that a car either WILL or CANNOT run better on 93 if it recommends 87. The most correct answer is, "it depends". It depends on how that vehicle's software is written and how much timing advance is allowed in the computer.


I suppose. FWIW, the 4.0L OHV engine does not have a knock sensor, so no ignition timing retardation automatically from knock. Nor have I attempted to adjust the timing. It does adjust timing but not due to knock, rather due to throttle position, load, etc.




Originally Posted By: Peted
Okay, I went and added you to the 'list'. I counted all the posters who have used both 87/premium with cars that did not require premium.

7 posters state no difference/worse performance on premium and 13 posters stated an improvement. Nearly twice as many.

The numbers don't lie.
smirk.gif



Touche!
 
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