itrhybrid

iTrader: (1)

Couple of questions. I have not read the entire 4 pages so I'm sorry if this was covered.

1. You mentioned penalizing factors. How did you alter the results to reflect the penalties?

2. How much did the 4+ containers of gas weigh? Did you take into account that on your last test, you were driving around with less weight (in the containers of gas) in the car compared to the first?

Thanks,
James

sauceman

No. my results are raw. But my deductions were taking into account those penalizing or helping factors, although not in a scientific way, so it still remains as approximations, though I would venture to say still pretty accurate.

I did not weigh the 4 gas containers. The weight loss would have only very minimally affected the results, since the difference between the beginning of the test and the end would be 3 containers, since the first one was in the tank to start with. I di pay attention to where I placed the containers in the cabin so as to spread the weight evenly in order not to weigh down too much on the front or the rear and disturb the aerodynamics of the car.

sauceman

Yeah, I'm sure the TSX would react very differently to the same test than with an Explorer.

I too, believe on the highway at cruizing speed, you're better off with A/C than windows open.

itrhybrid

iTrader: (1)

Or even better, if it's cool enough, windows up and just the air blowing, no AC.

James

sauceman

That was the case during my testing session. Actually, I would've suffered the 90° just to get the numbers down.

wclark

inspired by Jeff, I chose to do fuel economy as my Science Fair project here is my research paper.

This project will take place in the field of engineering. It will consist of taking a Honda manufactured engine and testing the miles per gallon output between two different types of gasoline. The car that will be used in the experiment will be a 2004 Acura TSX. The gasoline will all be from the same brand of Chevron. Chevron brand was chosen because it was picked by the top car manufacturers as a "Top Tier Detergent Gasoline". One gallon of each type of octane rating from Chevron will be used, and which octane rating produced the best miles per gallon will be determined. The experiment will be repeated three times to ensure accurate findings. At least fifty points will then be plotted in a scatter diagram and a conclusion will be made as to which octane rating is the better gasoline. The whole purpose of this experiment is to test whether or not it makes a difference if premium gas is used when called for and if it saves money in the long run by better gas mileage.
The Acura TSX contains a 200hp DOHC I-VTEC in line 4 cylinder engine[1]. The original VTEC engine was created by Honda engineers in 1995[2]. As stated by Honda VTEC stands for "Variable Valve Timing and Lift Electronic Control System"[3]. This type of engine was created by Honda to give their engines better power and efficiency. In normal engines the pistons open at the same rate and let in the same amount of air and fuel throughout the RPM range. In the Honda made VTEC engines the amount of fuel and air injected into the pistons as well as the actual piston speed varies based on the RPMs reached by the engine. The "I" in the I-VTEC is simply an evolution of the original VTEC system developed by Honda. The whole purpose of the conception of VTEC was to make the engine more efficient for the consumer and better meet their needs. Overall the VTEC system is much better than a normal engine which wastes fuel while trying to perform. The VTEC engine uses every single bit of power produced by the engine to make it more efficient and it gives the consumers an incentive to buy Honda engines.2
The idea of Top Tier gasoline was the culmination of many years of engine wear and break down. The major car manufactures of the world didn't like the fact that certain fuels were wearing down their engines and possibly giving that company a bad reputation. These car manufactures which included Honda, Toyota, GMC, and BMW devised a listed of certain standards the gasoline must meet to become the best of the best.[4] The list is actually stricter than that of the one devised by the EPA (Environmental Protection Agency). This list is composed of fuels that had a certain detergent level in them, so as not to leave behind fuel residue. This residue build up over time, can cause the engine to lose performance and cause it to break down quicker. The residue settles on the piston heads, and valves causing them to lose performance over time which could greatly affect the fuel efficiency originally achieved by the engine.[5] Chevron passes all the requirements of the list with the additive of "Techron". Techron is a special type of detergent that Chevron came up with and it can actually help undo years of engine miss-treatment caused by the other lesser fuels.[6]
Another factor to consider when talking about the fuel efficiency of an engine is the lubrication. Obviously, thicker, heavier oil will cause an engine to work harder, although some believe that the added protection is necessary. Using lower viscosity oil will not significantly affect the rate at which an engine wears down. However, it can help to provide a somewhat significant improvement in fuel economy. The type of oil used can actually save up to 5 percent on overall fuel consumption.[7] This may not seem like a huge factor to fuel economy, but out of 10 gallons of gas, there will be a .5 gallon savings, which adds up over time.
Many consumers who purchase vehicles these days make decisions based on the EPA tested and regulated fuel efficiency ratings. However, those ratings are becoming more and more out of date. Many times the EPA ratings are far better than in the real world. This is because those rating standards were created in the 1970's, when speed limits were generally lower, and congestion was much less of a problem for motorists. In fact most of the listed MPG ratings on the side of vehicles are never accurate because of the simple fact that they are so old.[8]
There are many ways that drivers can actually surpass those ratings. Those tips and methods will be used in testing to ensure the fuel is being used to its maximum efficiency. Any extreme motions that a vehicle goes through waste energy by turning their momentum into friction against the pavement. For example, quick acceleration, hard braking, or sharp cornering or swerving will all significantly reduce fuel economy, and should be avoided. In fact, it could be as much as a 33 percent highway or a 5 percent city deduction from the potential. Idling is a huge contributor to reduced fuel economy. While parents wait in their cars to pick up kids, the engine is burning fuel, usually it is wasting power turning an air conditioning compressor, and all the while it is going nowhere. The MPG will be 0 for as long as a car is idling, and therefore, bigger engines will always waste more fuel at idle than a smaller engine.[9]
Speed is also a big contributor to decreased fuel efficiency. Many people get the impression that the faster they go, the quicker they will get where they are going and therefore, will end up burning less fuel. This is completely wrong because the essential element of aerodynamic drag is being left out of the equation. On most cars, the maximum fuel efficiency can be achieved at 50-60 mph. At any speed below this, the car could go faster, sometimes in a higher gear, using the same amount of fuel. At any speed above this, the car encounters too much aerodynamic drag, and the engine must work harder to overcome that. Thus, the car may use 10 percent more fuel just to go 5 percent faster.[10] Other contributors related to aerodynamics are roof racks and cargo. When vacationers take a road trip, rooftop cargo carriers are often used. These add excessive drag, and usually interfere with the aerodynamic qualities that the vehicle was originally designed with. The same goes for trailers. Any excessive bulk or weight will decrease fuel economy, no matter the situation. If possible, all cargo is best kept inside a vehicle where it does not disturb airflow patterns around the car.[11]
Accessories on a car will contribute to increased fuel consumption as well. Audio systems, lights, heated/cooled seats, and any other electrical accessories must be powered off of the alternator, which must in turn be powered by the engine. The alternator causes a slightly increased load on the engine, and sometimes it can be a significant 5 percent. The biggest contributor is obviously the air conditioning. When it is turned on, the engine must mechanically turn the compressor, which wastes power that could be used to turn the wheels. Studies show that turning off the AC and rolling down the windows can contribute to a 5-25% increase in fuel efficiency. The drag increases with the windows down, but does not significantly affect fuel economy until around 60 mph, when normal aerodynamic drag is also decreasing efficiency.
Cruise control generally helps with fuel economy. On flat highways, a constant speed can be maintained and fuel consumption is regulated. However, on rolling hills or mountainous terrain, cruise control is not so great. If a car is traveling towards a hill with a 10% grade in cruise control, the car will work hard to maintain the same speed as it was going on flat ground. If a person drives, they can accelerate on flat ground, which is much easier for the engine, and use the gained momentum to get to the top of the hill. The cruise control would work the engine much harder to get to the top, and more fuel would be wasted. On a downhill, the vehicle can usually gain momentum simply by going down the inclined plane. Better yet, if the car is put in neutral, the engine can be idling while the vehicle constantly gains speed. Because gravity, not the engine, is powering the car through the wind, it does not matter how much speed is gained on a downhill. The momentum can be carried through to either the next uphill or onto the flat road again until the vehicle returns to the optimum speed for fuel efficiency.
There are many factors that contribute to fuel economy, as evidenced here. Vehicles have their EPA ratings, and many drivers achieve real world results around or below those ratings. However, by being a smart, smooth driver, those ratings can be easily achieved, and many times excelled8. With gas prices rising, many worry too much about the EPA rating that they think their car is always achieving. Before buying more fuel efficient vehicles, people need to be more efficient drivers. If the tips and tricks to do so are followed, every car has the potential to be much less of a gas guzzler, and much more of a fuel efficient green machine. ----------------------- [1] Tsx engine performance. (2005). Retrieved Oct. 12, 2005, from Acura Web site: http://www.acura.com/models/model_pe...asp?module=tsx
[2] intelligent-vtec - the next generation. (2000). Retrieved Oct. 12, 2005, from http://asia.vtec.net/article/ivtec/.
[3] What does vtec stand for? . (2005). Retrieved Oct. 12, 2005, from Acronym Finder Web site: http://www.acronymfinder.com/af- query.asp?p=dict&String=exact&Acronym=VTEC.
[4] Top tier detergent gasoline. (2005). Retrieved Oct. 12, 2005, from Top Tier Gasoline Web site: http://www.toptiergas.com/.
[5] Top tier detergent gasoline marks one year. (2005). Retrieved Oct. 12, 2005, from GM Web site: http://www.gm.com/automotive/fueleconomy/detergent.html. [6] ChevronTexaco meets new "top tier detergent gasoline" specifications. (2005). Retrieved Oct. 12, 2005, from Chevron Web site: http://www.chevron.com/news/press/2004/2004-06-17.asp. [7] Taylor, R., & Coy, R. (2005). Improved fuel effeciency by lubricant design : a review. Retrieved Oct 12, 2005, from http://www.iantaylor.org.uk/papers/IMechEFE2000.pdf. [8] Mpg standards to be revised by dec. 2005. (2005). Retrieved Oct. 12, 2005, from Daily Helmsman Web site: http://www.dailyhelmsman.com/vnews/d...41ef7982a44/?t emplate=default. [9] Getting the best fuel economy out of your tsx: tips & tricks. (n.d.). Retrieved Oct. 12, 2005, from AcuraZine Web site: https://acurazine.com/forums/showthread.php?t=2182. [10] Fuel economy experimentation. , Retrieved Oct 12, 2005, from http://www.nesea.org/greencarclub/re...nomy%20exp.pdf.
[11]Why is my outback only getting 21 mpg!. (n.d.). Retrieved Oct. 12, 2005, from Ask MetaFilter Web site: http://ask.metafilter.com/mefi/22788.

sauceman

Bass Mechanic

looks great however if you intend to use this for school you might want to revise some of it , for example
pistons dont open but rather valves do and air is not injected into a piston its allowed to flow into the cylinder or combustion chamber.
the longer the duration or the farther that a valve is opened or left open has everything to do with the amount of air fuel mixture that will enter the combustion chamber. because of the fact that when the engine runs at a higher RPM there is less time to fill the cylinder. therefore the VTEC system has an advantage over regular engines.
typically low lift and short duration cams give better torque while high lift and long duration cam profiles give better high rpm horsepower. the VTEC system takes advantage of both cam profiles.
the piston speed definitly changes with rpm but has nothing to do with the VTEC system. all cars have pistons that vary in speed except rotory engines which have no pistons.
the VTEC system has nothing to do with pistons but everything to do with valves. you might want to add that the VTEC system has 2 cam profiles and the I allows the intake cam to be varied. the I part has nothing to do with the amount of lift but allows for better cylinder scavaging which means that both intake and exhaust valves are open at the same time between the end of exhaust and beginning of intake strokes. the air escaping from the exhaust actually pulls additional air fuel mixture into the cylinder just before the exhaust valve closes giving a "supercharging effect" to the incomming air of the engine.

i think this would better written to say that honda develops engines that are more fuel efficient because they take advantage of more complex fuel map curves. in normal combustion engines a stoichametric mixture is approximatly (and you need to look this up as i forgot) is approximatly 14 parts air to 1 part fuel. honda develops engines that meet ULEV standards by making more efficient power with less fuel. i cant speak for the TSX but honda has a lean burn civic in development that raises the fel to air ration to as much as 30 parts air to 1 part fuel when the engine is highway cruising. the problem is that if you starve an engine of fuel it will generate excess heat and can cause engine failure. honda solved this problem by using special coatings on the pistons and combustion chamber to better deal with the heat issue.

so you see its not the vtec system in particular that helps honda engines be more fuel efficient. you can't get away from physics, you have to have both air and fuel to make an engine make horsepower. but its when and where you need the fuel that makes an engine run more efficient. the extreme example would be a carb on the old pre 80 engines they have no ability to change the mixture of air/ fuel into the engine they work of the total volume that goes through the carbretter.
fuel injucted engines with the assistance of the o2 sensor tell the computer the A/F ration and the computer then changes the duty cycle (on time) of the fuel injectors. this way fuel injected engines can regulate more precicely and when necessary richen or lean the fuel mixture.

hope this helps your research paper and i hope you get an A+ !!

zuiko

Hi,

Great write up.

The weight issue could have been addressed by filling the empty tanks with the equivalent weight of water - but i understand that you may not have known whether you'd stop where water was available. A second support car having a reservoir of water would be needed to do this more completely.

Also I'd like to point out that coasting in neutral or riding the clutch are not good driving practices. In the event you need to suddenly take evasive actions your ability to control the car with the accelerator is compromised when you are coasting. There's minimal engine braking when in 6th gear; and the importance of having full control of the car at all times is worth the small price in miniscule fuel consumption.

sauceman

Good point. I wonder what is the weight ratio between water and gas.

Here we go again. Those same overzealous people who hardly will use their flashers when turning, or will do speeding without a second thought (especially in school zones) are at it again.

We've been through this already, and I think the point has been made that if you are able to concentrate enough to coast in neutral and get back in gear with the right timing, you are way more concentrated on your driving than average Joe, and such a maneuver is not dangerous in any way. Read here: https://acurazine.com/forums/showthr...hlight=neutral

Plus, in case you haven't read this thread right, in a total of nearly 1400km of testing, I crossed about a dozen vehicles: This was purposefully a desert highway I chose.

But thanks for caring

HoRRo

Quote: The Federal Aviation Administration defines gas as 6lbs per gallon, Jet Fuel as 6.7lbs per gallon Diesel fuel as 9.24 lbs per gal. and water is 8.3lbs per gallon... So water is 2.3lbs heavier per gallon than car gas.. Just to throw a wrench in everything it all changes with the temperature of the fuel, it changes quite a bit. So those weights are based on about 60 degrees F

sandviper

amazing write up bra!!!!!!!

runner453

did you take into consideration that you tested the 91 octane in a lighter car?

Alin10123

"holy thread revival batman"

Nogard13

^ LOL at the Batman comment

Actually, one US gallon = eight US pints. Since a pint's a pound the world around, one gallon of water should weigh exactly eight pounds. I worked as an aircraft mechanic when I was in the military and we were taught that a gallon of jet fuel was 6.7 pounds and a gallon of water was 8 pounds. I don't know why the US military and the FAA would have different weights for the same amound of water.

Anywho, this is a good write-up. It could be measured more accurately the same way the Mythbusters did their fuel consumption tests for pick-ups (tailgate up, down, missing, covered bed, and mesh). They used a flow meter attached to the gasoline line and measured exactly how much gas was being sent to the injectors. A lot more precise.

BTW, mesh was the best fuel economy, followed by tailgate up, covered bed, missing and finally, tailgate down.

synthetic

LOL! why wouldn't the 2nd support car just carry the full/empty containers of gas?!!

godfather2

what a write up ... thanks for your dedication, sauceman!