Easy way to check gas mileage?

You write the mileage on your gas ticket, reset the trip OD to zero throw the ticket in the glove box and every so often, put them in a spread sheet that has been set up with all the calculators. Then, over time, you have a good read.

such as:

Subaru Forester

Tank no. miles gals mpg %highway highway miles city miles

1 263 9.76 26.95 65% 171.0 92.1 AC 2 276.1 11.036 25.02 63% 173.9 102.2 AC 3 271.5 12.168 22.31 0% 0.0 271.5 AC 4 280.7 12.199 23.01 0% 0.0 280.7 AC 5 236.5 10.851 21.80 0% 0.0 236.5 AC 6 222 9.486 23.40 64% 142.1 79.9 AC 7 255.7 11.305 22.62 31% 79.3 176.4 AC 8 530.7 24.486 21.67 0% 0.0 530.7 AC two tanks 9 10 2336.2 101.291 23.06 566.2 1770.0 24% 76%

Doesn't paste exactly lined up into the news reader, but you get the picture. BTW, not knocked over by the Forester mileage, particularly city miles. On the two tanks, missed a reset, no harm done just add the two tickets together.

Frank

I usually don't fill the tank unless I am going to NJ from PA, where gas is .40-.50/gal. cheaper, And they pump it, so was looking for ideas to check smaller fills. Really just want a rough idea, since big city driving can really cut in to mileage, though the new Sube has be exploring again. Introducing it (and me again) to some neat roads.))

VF

Fill the tank (let the pump shut off automatically. Do not top off.)

Reset Trip Counter to Zero.

Drive.

Fill tank again. Note # of gallons needed to fill tank.

Divide Trip Counter reading by gallons needed to refill tank for your MPG.

I keep a cheap solar powered calculator in the passenger cabin for this ritual.

You can also get a meter that plugs into your OBD-II port and will give you a constant readout of running MPG.

With the methods suggested it doesn't matter how large the fill is. The only thing that needs to be constant is letting the pump self shut down each time and don't try to push any more in the tank.

Frank

Its not feasible I'm afraid. Without filling the tank, or establishing some means of knowing a given gas tank level, you have no fixed measure of how much gas was consumed in the miles driven.

But I have an idea.

If you are interested in knowing your mileage, plan a trip to PA where you can in good fiscal conscience fill your tank, then, when back in NJ, affix a small red E to the instrument cluster where the 3/4 of a tank line is on your fuel gauge, and pretend you're running out of gas.

This will get you the emotional comfort of smaller fills, and be able to fill the tank on every fill, so you can resetting the trip odometer and have a chance of calculating mileage. And you'll never run out of gas.

Best Regards,

-- Todd H.

2001 Legacy Outback Wagon, 2.5L H-4 Chicago, Illinois USA

First mileage on my Forester was erratic but high. Found tires were inflated to 40 lb. which probably helped mileage. Others said this is common and dealer said they come like this out of factory but they did not adjust in car prep.

Frank

David; Tell me more about the meter for MPG that's driven by the OBD-11 port. Thank you, Lyle.

If the calculator is too cumbersome, you can get a little slide-rule sort of thing where you line up the miles and gallons, and it shows you the mileage. I got one as a freebie from my mechanic years ago that clipped onto the sun visor, and it was a great convenience for many years until it wore out. The nice thing was that you didn't have to write things down, since the slider would stay in whatever position you left it until the next time you gassed up (You still want to take notes if you're interested in more than a general "Did it get better or worse since the last time")

wouldn't the low fuel warning light come on at the same point? Read it won't go out unless you put 4 gal in. That eliminates my 5$ fill, or even 10$.(( Figure it wouild be pretty accurate, recording how many gal I put in and calc the miles till the light comes on again, and put more in asap, or add the miles since the light came on to the next # of miles, or is that subtract them??)

VF

I guess you could use that technique as a rather rough gauge (when it comes on does vary by incline IIRC). Would it give you two significant figures of precision in your mpg measurement? I dunno. When the tank's full and the nozzle shuts off, it's generally full with a rather low variation since the filler tube's diameter is such that you're not dealing with a lot of volume variation between different fuel nozzles, and the measurement ends up rather precise. With the low fuel light, you're dealing with a vertical fuel level measurement amplified over the area of a rather large tank.

But really what's the point? Why not start filling the tank with more regularity? Averaged, I challenge you to prove that you're saving any money with these partial fills unless you're actively changing your destinations based on getting to PA for fill ups with cheaper gas on a regular basis (and in that case, is the savings nulled out by the fuel burned to get out there?)

Best Regards,

-- Todd H.

2001 Legacy Outback Wagon, 2.5L H-4 Chicago, Illinois USA

You also need to record the amount of fuel put in over at least 3 or 4 fills. And it only needs to be 'full to the brim' at the start and on the last fill.

Back a few years I competed in some 'economy' events and we found that some cars had a flat top to the tank and the breather was not at the highest point of the tank. As a result sometimes there was a bubble of air trapped in the top of the tank when it was filled at night.The competitor thought he had had a wonderful day. It evened out over the next few days. At the end of the event on the final fill we always made sure the cars were rocked from side to side to burp any trapped air out of the tank.

Back then (mid 70s) we were getting 44MPG (Imperial gallon) out of a Corolla.

I don't drive all that much, and putting in 30$ worth at one time seems like a lot of money, even 20$'s does.. It's NJ where the gas is cheaper, and I only go when I have to, and then I will fill up, because of the price.

I was just trying to figure how to use some features the Sube has, to check mileage. After breaking the car in and learning all the controls, and adding all the parts I have bought to put on it, I may put very few miles on it, since I bought it as a more dependable ride to some distant places in a state forrest in NJ to go star gazing, and where relatives live.

VF

Partial fills should be avoided. There was a time when that was the only way I could drive and my daughter has hit-and-miss funds and does partial fills. It is common, but really, it increases the amount of moisture and debris that enters the tank , and there is more evaporative loss, when the gas cap is off.

Carl

But you realize this is all just mental. You're spending the money eventually anyway. You can go to the gas station just as often and put just as little gas in as you always do if you start looking at the

3/4 full mark at the Empty line. And you'll be able to figure out mileage reliably.

-- Todd H.

2001 Legacy Outback Wagon, 2.5L H-4 Chicago, Illinois USA

I had an injury that damaged all systems. Brain damage and I had to do my Own cognitive therapy, because I couldn't handle the 5 day, 6hr/ schedule, because I couldn't stay awake for more than 3 hrs. I would get So tired, I would hope I had enough gas to get to a station the next time I drove, because I coudln't stop on the way home, Getting home, even a few blocks, was pure agony. I had to relearn, math and spelling, because if short term memory damage, though long term was still in tact, so I would practice, and make up games and tests. Had to figure out the prices and add them up, Before i went shoping, so i didn't feel like I got overcharged. I couldn't do it on the fly, at the register. With the price of gas, and Knowing the oil co's are robbing us, and the war is About Oil, I buy gas Very reluctantly, and like if being robbed, if a mugger only got Some of the money you had on you, you feel like you didn't get taken for That much, I try to give them as little as possible. I usually only drive 2mi/day.

I smoke and smoke little filtered cigars that look like brown cigarettes, 20 to a pack. I get them at a wholesaler, and with No cigarette tax, they are costing me 1$/pk. Because the wholesaler is only open M-F 9-4PM, and because of my injury, I don't function that well in the daytime in traffic, I stock up. I never spent more than .

90/ pack for cigarettes, since when the name brands got that high, I found a cheaper one at .60/. When they went up I found the little cigars for that much. When they hit ,90/ I found the brand I smoke now at .45/. I was buying 180 packs at a time, so I didn't have to make the trip in the day that often, and they are only 1mi away. Now they are up to 1$/, and I only buy 120 packs. As cheap as they are, it still is a struggle to part with the money.

With my old car, if I fill up in NJ, I still run it down till the needed stops moving, and then I reluctantly buy more. Because I ran out SO many times when I was much worse, I carry a can of gas in the trunk. I haven't run the Sube down to see the light, but put 5$ in twice, and 10$ once, and 25 when in NJ. I thought about filling when in NJ, but have been going over more often recently, and to break in the Sube faster, I've taken some 100mi plus trips, to drive it in different areas, on different type roads, to get familiar with the car on them.

Everything is a learning and relearning experience for me. When buying something I get jammed up if I feel I am spending 1$ more than need be. It is a challenge to find or get the best price. Ebay was driving me crazy, and making my heart race and head hurt when getting close to the end of the auction. With the damage I have, I started to worry about having a stroke or heart attack for a few $, so eased up, and pick a price I can live with, and go with that, win or loose.

VF

yea, I know about partial fills and condensation. I used to work with aircraft fuels in the air force. The fuels are filtered, and icing inhibitors take care of the water. That's why dry gas isn't necessary now, and fuel pumps don't have removable glass bowls to see the water and dirt collecting in them.

VF

Those fumes seem to be getting to you.

Have you considered medical marijuana? Paxil?