I have an 06 coupe 5AT with no mods what so ever. Sunoco sells 94 octane. It's about 10c more per gallon than the 93. Would it be advantagious to use the 94? Would I notice anything? Or, am I just wasting money?

 

Highest around my place is 93 unless u get 104 racing gas which is like 5 bucks a gallon lol. But if we had 94 around here Id pay for it.

 

I imagine probably not because a lot of us are stuck getting only 91 and it works fine.

 

I would not pay 10 cents for only one octane point. But octane ratings are not the only considerations. The overall quality is fuel is just as important. Amoco Ultimate used to be the worlds best Gas. But I am not sure if that sill stands since the BP takeover.

 

The 93 is conventional, the 94 has 10% ethanol and thus will have 3-4% less BTU per gallon and will make less BMEP [torque/HP]............a negative that you don't want to pay money for. Much confusion intentionally created about the conversion to ethanol.

 

abbbbbbbbbsolutelly nothing.

but you can save all thsoe then later on get some 104 heheheh

 

Another consideration for Sunoco gasoline(any octane) is lower sulfur content. Sulfur combined with moisture in engine will form sulfuric acid.

And that BTU argument-how MUCH horserpower will you actually loose? If Q45Tech knows such details, maybe he will present us with numbers? HP per octane point or HP per ethanol content %?

 

Simple study ethanol BTU vs conventional gasoline BTU vs 10/90! Even the EPA and Chevron have warned you for years!

HP is an imaginary mathematical number created by James Watt to explain power to uneducated coal mine owners in England ------derived from torque and rpm ratio above and below 5252 rpms.


http://www.chevron.com/products/prod.../fuel_economy/
A gasoline engine is powered by the energy released when gasoline burns. Thus, it is not a surprise that gasoline containing more energy gives better fuel economy. The energy content of gasoline can be expressed in a variety of units; one of the most common is British thermal units per gallon (Btu/gal).

While anomalous results have been documented for some vehicles (see below), there is compelling evidence that the fuel economy of most vehicles tracks the energy content of the gasoline. Figure 4 shows the average laboratory fuel economy for two fleets of vehicles fueled with two different groups (matrices) of gasolines. The energy contents of the gasolines in each group were changed by varying hydrocarbon composition and oxygenate content.

That the results fall in two straight lines demonstrates that average fuel economy is proportional to energy content, and that the impact of gasoline composition on fuel economy is limited to its affect on energy content.

http://www.chevron.com/products/prod...etin/oxy-fuel/

Summary

Oxygenated gasoline will lower your car's fuel economy 2% to 3% because oxygenates contain less energy than conventional gasoline

Energy Content of Gasoline

The potential work that a fuel can do is determined by its energy content. One measure of energy content is British thermal units (Btu) per gallon. Oxygenated gasolines contain less energy per gallon than conventional gasoline1:

http://www.epa.gov/OUST/oxygenat/oxyother.htm

http://www.ext.colostate.edu/Pubs/farmmgt/05010.html

Graph in middle shows the 2-4% power loss vs rpm from using 10% ethanol vs conventional non oxygenated gasoline

If water is present in the ethanol this will add to power loss.

 

By the way all manufacturers use very special custom blends of conventional gasoline to rate engines power for dyno runs to publish power output specifications.

In Japan [testing] they use a TEST gasoline unavailable in US that has a BTU rating in excess of 120,000 BTU with a MON of 95 or >.........one of main reasons why Japanese engines don't meet spec here! Our fuel is so very very very bad. Even EU Premium is of a higher MON quality.

American engine testing companies usually use gasoline that might be available somewhere in US at some time of the year on at least one day.

http://www.ext.colostate.edu/Pubs/farmmgt/05010.html

Note farther down from previous graph that 10% Ethanol in gasoline actually produces MORE [15% MORE] NOx than conventional gasoline.........

There are lots of secrets the CORNy GUYS don't want the public to understand!

Because anhydrous ethanol is much more expensive to process the blenders at the tank farms are using 95% ethanol with 5% water thus the resultant contains at least 0.5% water. Before any mistakes occur to boost profits.....1% more free water equals 1% more profit

 

i think there are a few old posts about this subject check it out in a search

 

Thanks that was interesting. Just came to my mind-Sunoco actually advertised that 94 with 10% ethanol gives most power.
Oh well I guess it makes no sense to sue them now...

 

More power if your engine knocks on 93 which is really 92.5000000000000001 on a good day.

The Ethanol actually raises the MON octane part of the equation [averaged RON + MON = pump number] and can result in lower knock counts depending on the underlying 90% gasoline composition.

MON components cost 15% more than RON components SO CAN YOU GUESS which way the cost saving computers err.

US refiners have learned to make the cheapest awful performance gasoline known to man and still post 93 on the pumps....by the way there are no zero regulations that the number on the pump be ACCURATE. Just a marketing ploy! Until proven otherwise.

 

94 will do nothing for our cars. Unless you have a highly modded car that has been tuned to take advantage of higher octane, that is... It won't do jack shiet for NA sockish G's.

 

Data log the knock counts and ignition advance to determine what's right for your car on each individual day and temperature and barometric pressure.

For sure there will be a batch to batch variation as replenishment slugs come down/up the pipeline.

Find out the average replacement cycle at your local tankfarm.