Fact or Fiction?: Premium Gasoline Delivers Premium Benefits to Your Car

[Arnel]

http://www.sciam.com/article.cfm?cha...5F3705197C1D4F

Like we ever doubted Wolfman....

[davidsky]

Take the money you spend on Premium gas and spend it on Premium Ice Cream because a pint of Ben and Jerrys has a lot more benefits than 93 Octane.

[Shadow_tek001]

Originally Posted by davidsky

Take the money you spend on Premium gas and spend it on Premium Ice Cream because a pint of Ben and Jerrys has a lot more benefits than 93 Octane.

LOL



Edward

[K-1]

Originally Posted by davidsky

Take the money you spend on Premium gas and spend it on Premium Ice Cream because a pint of Ben and Jerrys has a lot more benefits than 93 Octane.

Truer words were never spoken.

[fireman5031]

Granted Ben and Jerry's Ice Cream is among the best ice cream in the world, and undoubtedly, if ingested, Ben and Jerry’s is much healthier for your body. However, I have found that with my '04 Vue Red Line, I was getting better mileage if I used premium over regular. I did the experiment and tracked it for 2 months. The first month, I used only regular gas, and the second month, only premium. On average, I achieved almost an extra 25 miles to a tank of gas with the premium octane. Interesting, I thought. I kept using the premium and the mileage kept up, but I never had the time to sit down to figure out if the extra 25 miles was enough of a gain to offset the extra cost. Nevertheless, I did get better mileage.

[NoRemorse]

Depending on the car, and how it is calibrated, it may get better gas millage out of higher octane gas.

On my car that has been 'tuned' (I hate that word) for 94 octane will get significantly worse gas millage if I put in low grade, or low octane fuel. It will revert to a 'low octane' timing map, and will effectively take out about 15 degrees of timing, that is a lot of power, and a lot of efficiency. For me at least, it would be about 60 miles a tank. Not to mention the damage to my engine that can occur in the time it runs in the high octane map (until it calculates that there is too much knock)

Of course, this only holds true if your ECM is expecting high octane, premium fuel. If not, it's not a big deal, they have the same detergents in them.

[walt]

Gas knock or pinging is the key from what I understand. If your engine pings and everything is set up correctly use 93 Octaine. Some older engines build up carbon on pistons and that may cause pinging(this is what I was told by the mechanics of old). If your car does not ping use 87 octaine. I use 93 in my 84 Corvette. My Corvettes 350 is modified and dumps much more fuel than the factory ever intended. It even has a newer fuel pump than the orginal because the orginal could not pump enough fuel. My computer was also changed to compensate for all this. Sure Im getting 9.6 mpg according to my fuel readout on the dash but who cares. Its one heck of a ride.Some of the mitsubeschi spyders, BMWs and some other cars require 93 or you will kill the motor.

[dieseljack]

There was a federal mandate some years ago that all domestic cars had to be able to run on 87 octane, regardless. The compression ratio on my 2005 Acura TSX calls for 91 octane, but the car will run on 87 with the knock sensor / ECM automatically retarding the timing in the event of any detonation, as it will do on any car. The tradeoff is a reduction in performance and fuel mileage. The risk is failure of the knock sensor to do its job, particularly with a six speed manual, as is mine, and resulting internal engine damage from detonation throws warranty out the window.

[NoRemorse]

Originally Posted by walt

Gas knock or pinging is the key from what I understand. If your engine pings and everything is set up correctly use 93 Octaine. Some older engines build up carbon on pistons and that may cause pinging(this is what I was told by the mechanics of old). If your car does not ping use 87 octaine. I use 93 in my 84 Corvette. My Corvettes 350 is modified and dumps much more fuel than the factory ever intended. It even has a newer fuel pump than the orginal because the orginal could not pump enough fuel. My computer was also changed to compensate for all this. Sure Im getting 9.6 mpg according to my fuel readout on the dash but who cares. Its one heck of a ride.Some of the mitsubeschi spyders, BMWs and some other cars require 93 or you will kill the motor.

Just because it doesn't ping, doesn't mean you should not use premium gas. If anyone read my post, you would know that many cars have 2 timing tables, and it will revert to the less efficient one if crappy gas is sensed (This DOES happen with knock/pinging, but happens faster than you can believe, and pinging on an engine this size is inaudible) For most/all NA cars, regular should be fine, but keep in mind that bad gas CAN hurt efficiency.

[bobc455]

Originally Posted by NoRemorse

Just because it doesn't ping, doesn't mean you should not use premium gas. If anyone read my post, you would know that many cars have 2 timing tables, and it will revert to the less efficient one if crappy gas is sensed (This DOES happen with knock/pinging, but happens faster than you can believe, and pinging on an engine this size is inaudible) For most/all NA cars, regular should be fine, but keep in mind that bad gas CAN hurt efficiency.

For me, it is not inaudible. It is quite clear. Now maybe that's because my ears are trained to listen for pinging (from the old days when I had to set the distributor), or who knows, but it is definately there.

I can hear pinging on 89 octane also, which is why I move to 93.

There is not a lot of pinging- as soon as the knock sensor hears it, the timing is retarded appropriately. However, that is strictly a REACTIONARY device, and timing is not retarded until after some pinging has occured.

And a lot of people don't know this, but when the engine retards timing to get rid of pinging, it will slowly advance the timing back toward its original setting until it hears pinging again. (echo: again again again)

So our engines are not really designed for 87 octane- rather, they rely on a protective device to change the timing so it can use 87 octane.

I wish that a "gauge package" included a gauge that showed the amount of knock retard. As far as I'm concerned, if the PCM EVER senses knock, the PCM should be reprogrammed under warranty.

Maybe an occasional light ping won't blow your engine to pieces, but over time the accumulated effect of those pings will take their toll on bearings and headgaskets.

-Bob C.

[daver]

High-performance engines, such as those in some sports cars or older, heavier automobiles, often boast much higher compression ratios. These cars—for example, Shepherd's Subaru WRX—require premium gasoline and will definitely knock without it. "I have to put the 92 octane in," he says. "It has a turbocharger."


And that's why I use premium.

[fireman5031]

So, whats the outcome? What is better to use? My Aura XE is rated for 87 octane, should I use the higher grade stuff just to be safe?

[daver]

You're OK with 87. My Redline has a supercharger, so they recommend premium for that.

My previous SC-2s used 87 and were fine.

[fdryer]

fireman5031,
It can reasonably be assumed that if the owner's manual specifically states that regular 87 octane gasoline is recommended then one should follow the recommendation. As it stands, why would vehicle manufacturers state in the owners manual one octane rating if the car absolutely requires a higher octane? If it can be proven without a shadow of doubt by an independent entity that can be accepted in a court of law then there are definite ramifications. Those ramifications are a failure to disclose, misinformation, false advertising, liability issues that the unknowing public will join together to litigate the vehicle manufacturers, and a sense that the vehicle manufacturers are conspiring to defraud the automotive public. By following the manufacturers recommendation instead of word-of-mouth hearsay you are using the minimum octane required to operate you engine properly. A higher octane is just more money for the gasoline retailer and little benefit to your motor, all things taken into consideration. The car isn't hauling a yacht, four atv's, a motorhome, etc., that would create an undue load upon the engine/transmission system. Then it might warrant buying hi-octane for the time being to allow the engine the slight advantage because of the higher engine load otherwise regular unleaded for everyday use.

By recommending fuel with an octane rating the vehicle manufacturers are protecting themselves from this liability issue especially when a higher octane is needed for high performance engines which are spelled out in the owner's manual and probably labeled appropriately inside the fuel door in bold letters.

[Batman87]

Premium gas provides no advantage on regular cars, all premium means is that it is less likely to combust early under compression(knock).

[JADEDSL2]

Originally Posted by Batman87

Premium gas provides no advantage on regular cars, all premium means is that it is less likely to combust early under compression(knock).

True, and the reason is because higher octane fuels contain more MTBE (methyl tertiary butyl ether), OR ETBE (ethyl tertiary butyl ether). Both of which are designed specifically to reduce the chance of knock. Premium fuel knocks less because it burns less violently. It's not as combustible. I'm glad I'm not the only person who knows this stuff.

[davidsky]

Originally Posted by JADEDSL2

True, and the reason is because higher octane fuels contain more MTBE (methyl tertiary butyl ether), OR ETBE (ethyl tertiary butyl ether). Both of which are designed specifically to reduce the chance of knock. Premium fuel knocks less because it burns less violently. It's not as combustible. I'm glad I'm not the only person who knows this stuff.

Where I live they use 10% ethanol.

[JADEDSL2]

Originally Posted by davidsky

Where I live they use 10% ethanol.

Yup, that's about normal. ethanol is ETBE, btw. same thing. Some places around here use 85% gas, 15% ethanol, some use 90/10.

[davidsky]

Originally Posted by JADEDSL2

Yup, that's about normal. ethanol is ETBE, btw. same thing. Some places around here use 85% gas, 15% ethanol, some use 90/10.

thought it was something like that. MTBE is illegal here I believe. NY

[lewdwig]

Ethyl alcohol isn't the same as ethyl tert-butyl ether, ether is a class of organic compounds which contain an oxygen atom connected to two alkyl or aryl groups of general formula ROR'. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether" . Ether molecules cannot form hydrogen bonds among each other, resulting in a relatively low boiling point comparable to that of the analogous alcohols. (Thanks Wikipedia). ETBE's CAS number is 637-92-3, ethyl alcohol's CAS number is 64-17-5; different CAS #, different chemical.