pumping gas. A new fraud?

Originally posted by Digital Deviance
In Michigan, we also have stickers that state the last date of inspection by the Wieghts and Measures Dept. If you think your not getting the gas you pay for, you wont be able to deduce this from your cars gas milage. ( as that can change based on things as simple as the current weather ) Next time bring a 5 gallon gas can, buy 5 gallons and see if it makes it to the mark. (Most fuel containers have the FULL mark to make exact measurements) If it doesnt add up, call a local news station with your evidence.

Hmm I will try that actually. Also, I will check for a sticker too. I never looked for one, so ill remember to look for one.

Cars get worse mileage in the winter because the cold air is denser, which means you need more fuel to maintain the the same air/fuel ratio.

reply to post by jasonm56
I'm all for conspiracies but you have to eliminate the obvious problems first. eh?

Really, this seems to be a great case of jumping to crazy conclusions with little or no evidence to back it up. Let's knock over the highly plausable solutions to the problem before riding the conspiracy train into the sunset...

As the second poster mentioned, cars lose efficiency and horsepower over time. Look at a show like Top Gear where they're always making cracks about "how many horses have escaped that engine over the years".

I'm not going to guess about the physics of temperature changes on the vehicle but that could have something to do with it - That is you're expecting the efficiency to stay the same but it's going down instead. Need someone with more physics experience than me to explain that.

Also, what place are you getting your fuel from? Here in Australia we have some petrol stations that just sell "Unleaded", "Premium" and usually some overadvertised "Super" type fuel that supposedly cleans your engine too.

This might sound irrelevant but stay with me. While some places can get away with just saying "Unleaded", "Premium" and "Super", other petrol stations list the actual octane rating of the fuel. I've checked and for some petrol stations Unleaded is 91 octane, for some that same basic Unleaded is 95!

It's not always listed though, some just list it under "Unleaded" rather than "Unleaded 91" or "Unleaded 95". This also applies to the higher quality fuels. So while you think you may be getting the same-old normal unleaded every time, you may actually be getting slightly lower quality fuel. It's not enough for me to care about on a day-to-day basis, but it's there and I think perhaps if this is the same in America this could be the solution to your problem assuming you've been to more than the one single petrol station.

Or it could be that the one single petrol station doesn't care about the difference between say, 91 and 95 octane petrol either and will take any from a supplier and call it "Unleaded", so you're getting fuel from the same place in the same quantities but their supply is actually subtly different and changing quality regularly.

Last but not least, is it possible you've simply miscalculated the MPG? Or have you driven in something like congested city streets this time instead of long open roads, because we all know vehicles consume a hell of a lot more fuel when you're stopping/starting and crawling through the city than when you're on the highway.

Hope that helps.

[edit on 28/3/08 by Duality]

reply to post by jasonm56


The sticker will be on the front of the actual pump, in plain view. (As far as I know, it is required by law to be plainly visable) The sticker is metalic, the inspection info is "etched" in the sticker as opposed to it be written on there, as this obviously makes it tamper-resistant. If you do follow through with the proposed test, please, let us know how it went.

[edit on 3/28/2008 by Digital Deviance]

Originally posted by dgtempe
reply to post by jasonm56

 

I'm all for conspiracies but you have to eliminate the obvious problems first. eh?

Yeah true. Im also looking for people who had the same experiences, too. I will investigate and thanks to all the people who gave me tips.

A 98' Monte Carlo should have an EGR (Exhaust Gas Regulation) system from GM. If there were any emissions related problems you would trip a check engine light. A solid light that does not blink indicates a problem with the emission system. The 02 sensors are a part of this system, if one of them was faulty you would trip a check engine light.

Check your spark plugs, air filter, and fuel filter, those three account for a lot when it comes to gas mileage and efficiency. Bad plugs may not fire a check engine light, only if your having serious misfires. A blinksing check engine light is a sign of a catastrophic failure and the car absolutely needs repair.

You also have to remember the reason you get worse gas mileage in the winter is because the gas companies use a winter blend which has a higher hydrocarbon content than the summer blend, especially if you live in a state where it gets cold. The reason for this is because smog rules arent as strict for the winter months therefore the gasoline need not be as pure. This equates to a 2-3 mpg drop in fuel economy.

The station may have gotten a bad batch of gas ( this is fairly common especially in the tranistion months from warm to cold around october/november and cold to warm april/may) a higher ethanol content will hurt gas mileage as it has a lower air to fuel ratio than gasoline. gasoline is about 12:1 while ethanol is about 9:1, it takes more ethanol to achieve the proper mixture.

On the subject of ethanol. It is roughly 20-30% less efficient than gadoline and roughly 20-30% cheaper than gasoline depending on your location. It is a "green" choice because it produces cleaner emissions not because it is a better value.

Your cars computer tailors itself to your driving habits. If you usually floor the car around, then drive it like a grandma you'll get even worse fuel economy because your car is programmed and accustomed to your other driving style. You would need to reset the computer (disconnect negative battery terminal) drive light footed for a full tank, then start recording fuel economy on the 2nd tank.

I don't see a conspiracy here, IMO.







[edit on 29-3-2008 by BluByWho]

While I may not log-in alot, I do watch the forums almost everyday. This thread caught my eye, because I have the same thoughts as the OP.

I have a 2003 Chev 2500HD with the 6.0l It's my only personal vehicle, and I use it for snowplowing & lawn service, plus for personal use. Anyways, I've always received bad gas mileage - about 12mpg - which I expected when I bought it. After I put a topper on it, it jumped to about 13.5mpg. The truck has 18,000 miles on it when I bought it in late 2005. Now, in early 2008, it has about 45,000 miles.. It's oil gets changed every 3000 miles, and the air filter gets changed every 6 months.

I am not a lead foot, and while my fuel mileage does drop in the winter, this past fall & winter I was lucky to break 10mpg. Average now (within the last 6 months) is about 9.5 to 10mpg. - no tow load or cargo, other than a few sand bags which I've always had since day 1.

I noticed 1 day when I was on empty, and the message center said I had enough for 10 miles driving. So I go & fill up at the gas station. 99% of the time when the message center displays this info, I top out at just over 23 gallons. But 2 times this past winter, it said I put in over 27 gallons. However, I only have capacity for just under 26 gallons.

It's just always stuck in the back of my mind, and wanted to share this. Not really sure what to make of it, because I now have a company vehicle, so I save alot in $$ weekly in this poor econemy.

As for E85 - DO NOT USE IT unless you have a "Flex-Fuel" vehicle - it will state so in the fuel tank door and in your owners manual if you have a "Flex-Fuel" vehicle. Ethonal will break down the fuel lines and main fuel system componants of a regular gasoline system if it's NOT a "Flex-Fuel" vehicle.

Also, make sure you fill up in the mornings or at night, and also make sure your tire pressure is at the recomended air pressure. Not so much as to what your owners manunal state, but what the tire side-wall states.

And if you take your vehicle in to get serviced (oil change, etc), make sure they fill the tires with the right amount of pressure. I recently took my Chev in for service, and the kid adjusted all my tires pressure to 35PSI - he said they were all over inflated and passanger cars & trucks can never have more than 35psi in the tires. I had to show him that on my truck tires (245 70/16) are to be inflated to 65 PSI per the tire side wall and made him fill it back up.

reply to post by Spoontoad


I don't know about Chevy, but Ford puts a small reserve tank in. It's enough to get you a resonable distance to a gas station. Some of the other cars I've owned have had one too. I've put just over 12 gallons into a 12 gallon tank with a couple of my cars.

I have a pal who filled his Harley with aircraft gasoline from the local airport. He claimed the high octane made his Harley run and idle much, much better and it was faster.

Now gas is watered down from the local petro trough and I have the same problem with my Pontiac van going from 27mpg to now 17mpg. This is the worse its ever been. I think regular gas is mixed to heavily with that corn oil or what ever it is they shaft the consumer with now days.

People use Avgas in their cars, but it has to be used in a very specific blend. It's 100 octane, and it can cause damage to the engine if it's not mixed with regular unleaded.

I was having similar problems with my car as well. Not to mention it had been running quite strangely, couldn't figure out why. Then While filling up at the local gas station I always have used, I notice a new little label on the pump - This gas station dispenses an ethanol blend gasoline. Needless to say the very next day I changed gas stations, the extra 5 cents a gallon is worth it for the added 20% mpg increase.

One would think they would advertise they run an ethanol blend on a much bigger area, not the 2 inch by 2 inch sticker kinda hidden off to the side on the pump. I guess they assume everyone driving a car that is capable of handling such fuel.

reply to post by jasonm56


Interesting theory. There was an internet article I had read that showed a group that suspected that a locally owned gas station was tampering with the metering of the fuel at the pump, even after it was sealed and inspected by the auditor. They did this with the use of a special 'chip' which controlled the counting of the fuel at the pump to give it an error in the favor of the gas station. The clerk would simply flip a switch to turn it on and off, so that when tested by the county all would seem normal.

What they did was that they set up a special car with a calibrated volumetric container inside to collect the gasoline, and they conducted a sting operation on the gas station. They bought fuel and measured it against their receipt to see if it was accurately metering out the fuel.

You too, could probably test this by simply having a second container that is accurate. If you see a large discrepancy in the amount pumped, you could tip off the auditor or sheriff and have them investigate.

Now for the less conspiratorial angle. Winter and Summer gasolines are different and blended for the seasons to be a trade-off between driveability, fuel mileage, and pollution. It would not surprise me to see a noticeable difference in mileage between the switch of the two fuels, but it's hard to say if you knew which one you had or if it just isn't something wrong with your car making it perform poorly.

Cars after the mid 90's even have a learning feature built into the fuel management systems that allow it to fine tune the fuel and spark curves to the drivers habits. If you drove aggressively one week, and then promptly started driving miss daisy the next, it could just be that your computer is still following the old management map of how you drove and hasn't compensated for it yet.

If all this fails to sway your thoughts, maybe you left the emergency brake on.

Just so everybody understands I know my mpg will go down in the winter. Its starting to feel like spring, so I should be getting BETTER mpg. Thats why im confused. No sensors came off and I used new STP products and airfilter. I will be making a stop to the gas station possibly monday.

I remember reading a bit ago about the difference between getting gas in the morning versus the afternoon. The heat would cause thegas to expand, so you would get say, five gallons of gas, but it wouldn't be the same asgas yougot in the morning. Since you are coming out of winter, the gas is bound to be a little less... condensed I guess?

Originally posted by jasonm56
Just so everybody understands I know my mpg will go down in the winter. Its starting to feel like spring, so I should be getting BETTER mpg. Thats why im confused. No sensors came off and I used new STP products and airfilter. I will be making a stop to the gas station possibly monday.

Have you checked out my suggestion regarding the octane rating of the fuel? XD

I get the impression it's been overlooked but it is plasuible in my opinion.

I used the same fuel "unleaded" from the exact same place (Super America). Im pretty sure they dont change what its called no matter where you go. I do know that states have laws that say how much to mix.

My ex wife drives a Mitsubishi Mirage with 240,000 miles on it,she gets 37 mpg, I have a 2007 with smaller motor and get 35 mpg,mine only has 20k on it,so so much for comparisons of motors,btw I have a Land Rover that gets 12 mpg... downhill

There are a lot of things that effect gas mileage.

RPM isn't the ultimate evil. Using the most efficient part of your power band to accelerate to speed, then using the least amount of engine power to maintain that speed will give you better gas mileage.

Idling is your worst enemy. You are getting infinite negative mileage, since you achieve no distance for the fuel you consume.

Cool temperatures are good, hot and cold are bad. Too cold thickens the oil (more resistance), spend more time warming the car up (idling), and can lead to bad road conditions (snow and ice). Too hot, the biggest hit is a/c, which can lower mileage 20-30%.

Driving habit makes the most difference. This combines minimizing idling, coasting as much as possible, and using your brake and accelerator pedal as least as you can. Conservation of momentum is your ally. When you use your brakes, that fuel you burned to build up kinetic energy gets turned into heat by your brake pads and rotors. So, you see a light will turn red before you get to it, or a stop sign coming up, let off the gas early and coast as long as you can. For a red light, any left over speed if it turns green before you reach a stop helps a lot. Going speed limit can help a lot too, most cars are the most efficient in the 35-55 mph constant speed range.

Again, idling destroys mileage. This is why Hybrids have 'auto-stop'. The engines turn themselves off at stop signs and red lights (some turn off under 5 mph under braking), as to not waste fuel while sitting still. If you allow the car to start back up, you can watch the mileage drop.

Fuel is a factor as well. The octane rating shows its ability to resist detonation. So, 87 octane is more combustable than 93, but it also can lead to pre-detonation which is bad for valves, rods, pistons, etc. Early ignition can come from the cylinder being too hot or high compression, among other things, and this is why high performance cars usually take a higher octane, to protect the tuned engine that usually runs a bit hotter with a higher compression. As others have stated, Ethanol has less energy per unit, so for the same amount of fuel injected into the engine, less power is produced, which can lead to a lower mpg stat.

Tire pressure also plays a big role. 20 psi will take a several mpg hit. Factory recommendation is better. Though not advocating it, as the tire pressure increases, the rolling resistence decreases, so the higher you feel comfortable with the better. At a few sites where people try to maximize their mpg, some pump up to max cold pressure on the sidewall, some even go to the 50 and 60+ psi in each tire. They notice more even, and less wear on their tires. The difference between 40 and 60 psi is minimal compared to the difference between 20 and 40 psi. So keep your tires to at least the factory recommendation, if not close to the tire's max cold pressure.

Extra weight. If you have a trunk and cabin full of stuff, it takes extra energy to move those items. If you do something such as add bigger, heavier rims and tires, then it is magnified, since, rotational weight takes more energy to accelerate than dead weight (just as replacing a 24 lb flywheel with a 12 lb flywheel will help more than you going on a diet and losing 12 lbs).

Cars can increase in efficiency in the first 10-20,000 miles. If well maintained, the amount of power loss is minimal, especially if you don't 'drive it like you stole it', excessive rpms does create excessive wear in most non-rotary vehicles, rotaries do seem to perform better when driven consistently more 'spirited' (3000 RPM+ to below redline), though that isn't good for mpg!

If you have been topping the car off when you fill, you will already have an idea how many gallons you should be putting in compared to what the gage states. Occasionally there is a pump somewhere that is messed up. But, the state isn't helping them screw customers, for, they make quite a bit of money from fines if the company intentionally messes up a pump to their advantage. Every pump is to be inspected every year, even tested to verify that the premium is premium and the regular is regular. Most mid-grades use a mixer to combine the two grades so they don't have an extra underground tank just for that.



So, in the big picture, how do you drive? Do you conserve momentum? Do you keep the lowest weight oil in your car that is recommended? Do you have excess weight in the car? Do you keep the car in good maintenance, including tire pressure? Do you live in hilly or traffic congested areas (has the route changed as such)? What is the weather like? Do you use a/c a lot?


I drive a Civic Hybrid. I started out in the low 40s and high 30s on a bad day. Now I consistently get 50+ and mid to high 40s on a bad day. I have highway trips in the 40s going excessively fast, 50s-60s going the proper limit, and in the 80 mpg range going 55-60 mph on a long trip, over 1000 miles on a 13 gallon tank.

I have also gotten 50 mpg out of a 4-door Accord EX on a long trip.


What I am trying to say, it is more than just what RPMs you go up to, but a whole array of variables that influence your mileage ... but the biggest factors are the driver, the maintenance/health of vehicle, the fuel, and the accessories you run.


Check out CleanMPG.com and read through their threads and articles for a much more in depth take on these things. Some of it is overboard, but the general idea is conservation of fuel to save you money no matter what you drive, be it a F150 or a hybrid. Actually I think their motto is 'learn to raise fuel efficiency and lower emissions in whatever you drive'.

You may be able to bring that Monte Carlo up in the mid 20s to low 30s city and above 30s mpg highway with just a few minor tweaks and adjustments to your automobile ways.

Originally posted by jasonm56 It says 11 gallons, but I think I should of only used about 9. Do you think it could be possible the government is taking even more money out and using it for something?

You "think" that you should have only used 9 gallons?

Do this, fill it up at the same time of day, exactly the same way, if you top it of, do so each time, for three times. Drive it for at least 100 miles each time, and check the miles per gallon.

Take the average of your three readings.

This is going to be the most accurate performance of your car, as mpg can vary due to weather, heat, humidity, driving style, and many factors.

Then, if you still think it's too low, get a tune up.

And do it again.

If it still is only 15 mpg, have someone check the car thoroughly for leakage, the gas pump, all factors.

If you cannot find any explanation then, it is feasible you have some kind of problem to fret about.