5th & 6th Generation (2002-2006 & 2007-2011)Toyota Camry Discussion for years: 2002-2006 & 2007-2011
Topics of discussion range from fuel economy, safety, modifications, performance all involving America's favorite family car, the Toyota Camry.
that is too much reading but i skimmed through it and caught this:
"When you drive up to a gas station and see the different grades of gasoline... Basic, Premium, Plus... etc... These are just different grades of molecule spacing. They're making the gas more effective, and charging you more money for it!"
now people are going to think that a higher octane is going to get you better MPGs which is not the case if the vehicle just requires 87 octane.
i dont know if its true or not but sales advertising always tries to convince people that their product is superior. in this case it sounds good but hard to belive that it may be true.
^ your right, if the car requires 91 for the estimated MPGs and power then add 91 to the higher compression engines.
if the stock vehicle requires 87 then your not doing much by adding 91 as it does not require it. there are too many octane threads in the 05+tacoma forum so i wont talk any more about that.
about the fuel only being about 30% efficient is a fact and can rarely be changed. it is inevetible due to the explosion in the cylinder and the heat produced gets transferred to the cylinder wall, then to the engine components and cooling system. lets also consider all the friction that is happening through out the drivetrain till the power actaully reaches the wheels.
hey, im up for new things but im not willing to test till a reputable company does so.
this reminds me of a tire company that advertised that their tire would produce lower hydrocarbons due to less road friction. i didnt read too much on it and never read real results.
In many high-performance situations, riders clamor for higher octane fuels, thinking this will give them additional horsepower and, thus, an advantage over the competition. But this is not the case--adding higher-octane race fuel to your car may actually produce less horsepower. Here's why: Octane, an arbitrary number which is calculated as the average of the Research Octane Number (RON) and the Motor Octane Number (MON), and is only an indication of a fuel's sensitivity to knock, which is typically pressure-induced self-ignition. (Of these two ratings, MON is more applicable to racing fuels as it is measured under high load and high speed conditions.)
Octane, as you can see, is not a measure of how much power--or, more correctly, specific energy--is contained in a fuel. And remember that leaded high-octane race fuels burn slower than most unleaded fuels, and may reduce performance in stock or lightly modified cars. A high octane rating itself, however, does not mean that the fuel is slow burning. Hence, it has no direct bearing on the power characteristics of the fuel.
The knock tendency (and hence, the Octane rating) of a fuel is a function of the amount of free radicals present in the fuel prior to ignition and can be reduced by the addition of tetra ethyl lead, aromatics and other additives.
Although some racing organizations still use maximum octane number as the discriminating factor for fuel legality, it is really not appropriate for racing purposes.
Instead one should look at the amount of energy (heat) released in the burning of a particular fuel. This is described by the specific energy of the fuel. This quantity describes the amount of power one can obtain from the fuel much more accurately. The specific energy of the fuel is the product of the lower heating value (LHV) of the fuel and molecular weight of air (MW) divided by the air-fuel ratio (AF):
Specific Energy = LHV*MW/AF
For example, for gasoline LHV= 43 MJ/kg and AF=14.6, while for methanol LHV= 21.1MJ/kg (less "heat" than gasoline) and AF=6.46 (much richer jetting than gasoline). Using the above formula we see that methanol only has a 10% higher specific energy than gasoline! This means that the power increase obtained by running methanol, with no other changes except jetting, is only 10%. Comparing the specific energy of racing and premium pump gas you can see that there is not much, if any, difference. Only alcohols (such as methanol or ethanol) have a slightly higher specific energy than racing or pump gas.
Other oxygen-bearing fuels, besides the alcohols and nitromethanes, such as the new ELF fuel, will also produce slightly more power once the car is rejetted. However, at $15.00 to $20.00 at gallon for the fuel the reportedly minor (1% - 2%) improvement is hardly worth the cost for the average racer.
The real advantage of racing gasolines comes from the fact that they will tolerate higher compression ratios (due to their higher octane rating) and thus indirectly will produce more power since you can now build an engine with a higher compression ratio. Also, alcohols burn cooler than gasoline, meaning even higher compression ratios are possible with them, for even more power.
The bottom line here is that, in a given engine, a fuel that doesn't knock will produce the same power as most expensive racing gasolines.
However, it sometimes happens that when you use another fuel, the engine suddenly seems to run better. The reasons for this are indirect: First, the jetting may be more closely matched to the new fuel. Secondly, the new fuel may improve the volumetric efficiency (that is, the "breathing") of the motor. This happens as follows: Basically a fuel that quickly evaporates upon contact with the hot cylinder wall and piston crown will create additional pressure inside the cylinder, which will reduce the amount of fresh air/fuel mix taken in. This important--but often overlooked--factor is described by the amount of heat required to vaporize the fuel, described by the 'enthalpy of vaporization' (H), or 'heat of vaporization' of the fuel.
A high value of H will improve engine breathing, but the catch is that it leads to a different operating temperature within the engine. This is most important with two-strokes, which rely on the incoming fuel/air mix to do much of the cooling--even modern water-cooled two-strokes rely on incoming charge to cool the piston. For two-strokes a fuel that vaporizes, drawing a maximum amount of heat from the engine, is essential--the small variations in horsepower produced by different fuels are only of secondary concern.
Also important is the flame speed: Power is maximized the faster the fuel burns because the combustion pressure rises more quickly and can do more useful work on the piston. Flame speed is typically between 35 and 50 cm/sec. This is rather low compared to the speed of sound, at which pressure waves travel, or even the average piston speed. It is important to note that the flame propagation is greatly enhanced by turbulence (as in a motor with a squish band combustion chamber).
The most amazing thing about all this is that you can get the relevant information from most racing gasoline manufacturers. Then, just look at the specification sheet to see what fuel suits you best: Hot running motors and 2-strokes should use fuels wit h a value of "H" that improves their cooling, while more power (and more heat) is obtained from fuels with a high specific energy.
By the way, pump gas has specific energies which are no better or worse than most racing gasolines. The power obtained from pump gas is therefore often identical to that of racing fuels, and the only reason to run racing fuels would be detonation problems, or, since racing fuels are often more consistent than pump gas--which racers call "chemical soup"--a consistent reading of the spark plugs and exhaust pipe.
about the fuel only being about 30% efficient is a fact and can rarely be changed. it is inevetible due to the explosion in the cylinder and the heat produced gets transferred to the cylinder wall, then to the engine components and cooling system. lets also consider all the friction that is happening through out the drivetrain till the power actaully reaches the wheels.
For a gasoline engine, 30% is pretty good. Most gasoline engines will fall in the range of 25%-30%, some even as low as 20%. The other 70%, or so, of energy is lost as heat through the exhaust, cooling system, friction, or just radiated from the block, etc. BMW did devised a system that recovers the heat for an auxiliary drive unit that reduces fuel consumption by about 15% and adds about 13-15 HP but weighs ~220lbs.
Diesels are maybe 20% more efficient even considering the weight penalty of the diesel engine (diesels are built tougher than gasoline engines because of much higher compression ratios).
Google once again will show you what's going on. You'll have to wade through a few hundred sales-type links before you start finding critical information that shows this is no better than any other snake oil you could dump into your gas tank.
Also, there's a whole bunch of "multi-level marketing" going on about it -- the reason for the few hundred sales-type links I mentioned above.
I'd say "avoid this stuff." If you want better mileage, get a 4 instead of a 6. Get a smaller car and/or a hybrid. Learn how to drive more efficiently. Cut down the number of miles you drive, period. Slow down on the freeway. And so on.
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Has anyone seen this MPG??
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