Matrix MPG comments.

Hello all,

At the risk of bringing up a tired, old subject... I have a 2004 Matrix XRS that was giving me about 28 - 32 mpg with normal driving like shifting at 4 or 5k. Well, that was normal for me. Since gasoline started skyrocketing, I changed my driving habbits. I did a few things and I think I'm getting about 38 mpg--I'm just not sure if I'm calculating it correctly.

How accurate is the gas gauge? This afternoon, I realized that I had traveled 240 miles on half a tank. I believe car's gas tank is 11.9 gals.

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Thanks.

Reply to
nightrider.36
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All Toyotas I've had had weird gas gauges. From full to half they move slowly but from half to empty they move much faster.

The only way to get a fairly accurate assessment of your MPG is to fill your gas tank at the same gas station at least three times. Fill it the same way each time. Have the pump click three times for example or maybe just once to eliminate any manipulation on your part. Zero your tripmeter and drive around to your heart's content for many days. Come back and fill up the gas tank the exact same way you did before and print out the receipt. Divide the miles driven into the gallons purchased and you will have your MPG. Do this several times and you will get a decent knowledge of your average MPG. Try it once on a highway trip and see what you get when cruising.

Reply to
badgolferman

Sorry, I meant to say it the other way. Divide the miles driven BY the gallons purchased and you will have your MPG.

Reply to
badgolferman

Follow Scott and Badgolferman's advice for calculating MPG.

The gas gauge is not an accurate way to measure fuel economy because the shape of the gas tank is not uniform, and the fuel sender float moves in an arc as fuel level rises and falls. The arc movement is the reason the gas gauge moves more slowly for the first and last quarter indicated, and more quickly for the middle two quarters indicated.

Reply to
Ray O

It makes sense but it seems to me that you'd have to completely empty your tank down to fumes to get the exact capacity. If I pumped 10 gallons of gasoline, how would I know when my car's used up exactly 10 gallons? This doesn't seem very acurate, or am I missing something?

Reply to
nightrider.36

That would drink the gas... I bet I hardly ever go much over 3k with normal driving , acceleration. I don't know if I've ever had my engine up to 4k or not... To me, that would be kicking the foot in it.. I do have an auto tranny though..

Well, that was normal for me. =A0Since

I could see a Matrix getting 38 if you drove right. My 05 Corolla can do 41-42 on the highway if you keep it under 65. And I do careful checks. Both city,mixed, and highway. IE: I drive to OK a lot.. Usually at night. I can leave Houston with a topped off tank and I'll get more gas about 80 miles north of Dallas. And I'll still have a 1/2 tank at that point. The speed limit at night is 65 on I-45, and I'll put it on cruise and just kick back. I've done this exact scenario quite a few times, and I get 41-42 mpg every time. Actually pretty close to 42.

Dunno, I think it's about 13 actually, but I've never been able to put more than maybe 12 gal into it. My average fill up will be 10-11 gallons. I'll still have a gallon or two floating around in there when I'm on "E", and I usually will start looking for a station when the light goes on.. As others have mentioned, the first half goes slower than the second half. And I get pretty close the same after a half tank. IE: 225-240 or so miles. There is not a lot of difference between the Matrix and the Corolla besides the Matrix's higher roof line, etc.. Keep your tires pretty hard. Besides driving right, the tires probably make the 2nd biggest difference. I run about 34 lb's on average. Pretty hard, but it rolls easy.

Reply to
nm5k

To check fuel economy, start with a full tank and the trip odometer set to zero, or note the mileage on the vehicle odometer.

The next time you get gas, note the mileage driven since the last fill up and divide the mileage driven by the number of gallons it takes to re-fill the tank. The result will be miles per gallon, or MPG. Reset the trip odometer, and do the same thing for the next tank until you have several MPG readings to compare.

The only thing the gas gauge is good for is to know when to buy more gas.

Reply to
Ray O

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