Surprising increase in truck MPG

I improved my MPG quite a bit recently. I changed my air filter. There are quite a few things one can do to improve mileage that are cheap or free.

Steve

Reply to
SteveB
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Don't forget that the OP is actually 'eyeballing' his gas gauge for these 'tests'.

He is 'not' checking his MPG, only his eye's accuracy on guessing what a gauge reading means....

When his 'eyeball' says the needle is on E, he fills up and thinks that is his 'gas mileage'. He says he does have a gas can 'just in case'. but has never actually run the tank empty in 'reality' to test how far a full tank might take him, nor has he ever done an odometer vs volume check.

Just an observation most here are ignoring for some strange reason.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08. Some Canadian Bush Trip and Build Photos:
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Reply to
Mike Romain

Also, because of the variations in how far you fill the tank, one single milage measurement counts for little. Too much statistical variation.

Take the average of at least ten fills. Record the data for each fillup. Then do statistical analysis. This is getting easier with cheap calculators that have this function (sigma or variance). You need to know the variance because any change less than the variance is not worth considering.

Reply to
Don Stauffer in Minnesota

Do you really think this is a reliable way to establish mileage? Is this something new? Has this ever been proven? What would happen, say, if one would do this over ten tankfuls? Do you think this would give an accurate measurement over a long trip? Do you think anyone under 25 could do the math?

WHAT AN OUTSTANDING NOVEL IDEA!

Steve

Reply to
SteveB

It is a Silverado 2500HD pickup with a 5.9 liter engine, not sure about axle ratio.

Reply to
Ignoramus11166

I have receipts for gas somewhere, I can find them. The number of gallons added was more or less consistent every time.

i

Reply to
Ignoramus11166

I find that hard to believe, but I suppose it might be possible with closed-loop engine controls, a high-compression engine, and a knock sensor/spark retard *if* you were previously running on low-octane Mexican fuel. Not all vehicles have closed loop, however (basically any engine without an oxygen sensor has no means of feedback mixture control) and I just don't see any mechanism by which a less energy dense could actually produce a lower BSFC at the same power output.

Higher octane doesn't mean squat unless you also mill the heads or otherwise increase the compression ratio.

I'm curious how you come to this conclusion...

nate

Reply to
Nate Nagel

Easiest thing is to reset the trip odometer every time you fill up. Fuel consumption is miles driven since the last fillup divided by gallons added, modulo small differences in "fullness" (or liters divided by km driven if you want to do the metric reciprocal thing).

Best regards, Spehro Pefhany

Reply to
Spehro Pefhany

Axle ratio should have been listed on the window sticker. It's also one of the codes on the glove box RPO sticker. Axle ratio can make a pretty large difference in performance and MPG. A vehicle hauling a lot of weight does better with a high ratio, while a low ratio is best for MPG, but hurts hauling performance.

As a comparison point, my K3500 DRW with 7.4 l engine and 4.56 axle ratio gets about 11 MPG moving it's 7,000# with or without the first few thousand pounds of cargo. Loaded with a 2,000# truck camper, 10,000# trailer and additional cargo to 20,000# gross, it gets about 9.5 MPG.

I don't have first hand experience with your model truck (I'm sure others here do), but I would expect it to get perhaps 16-18 MPG if it has the default low axle ratio. If it has a GVW under 10k it should have some EPA MPG estimate numbers (also on the window sticker) that should be reasonably close to what to expect.

I'd take a few weeks of filling the tank and logging the mileage to get an accurate MPG number and see where you really stand.

Reply to
Pete C.

Global warming

Reply to
Jim Insolo

Not a good idea, really. The in-tank electric fuel pumps that most manufacturers are using these days depend on a continuous flow of fuel to keep them cool. Repeatedly running the tank dry will dramatically shorten the life of the pump.

Almost 26%, actually. (25.6 to be precise)

Please note, however, that you're measuring miles per *tankful*. Not miles per

*gallon*. Has the amount of gas that you're pumping changed?

You *will* see better fuel mileage with synthetics, but not 26% better. Two to five percent, maybe, but not 26%.

a) Anything of that nature that was going to happen, already happened a year ago, and b) wouldn't make that much difference anyway.

You'd be the best judge of that. :-)

Additional explanations that you've overlooked:

4) Warmer weather. Yes, it *can* make that much difference. 5) Other maintenance done at the same time as the oil change, maybe something seemingly insignificant that you've forgotten about -- like making sure your tires are properly inflated. Yes, it *can* make that much difference. 6) If you always buy your gas at the same station, it's possible that they screwed up and put premium gas in the underground tank that's supposed to hold regular. If your fuel mileage suddenly drops back to its previous level, I'd be more inclined toward this explanation than any other. 7) *You've* been screwing up, and pumping premium instead of regular. OTOH, I'd think you'd have noticed this the first time, when you went to pay for it; seems unlikely you'd make that mistake three times in a row. 8) One really hot day, that raised the pressure inside the tank just enough to pop out a large dent. You're getting more miles per tankful because you're getting more *gallons* per tankful, but your miles per *gallon* hasn't changed.
Reply to
Doug Miller

Not so fast!

I don't see any cites here. Where are the government statistics showing this to be valid in Illinois?

Reply to
Don Foreman

Not *that* much. Assuming that his figures are accurate, he only gets about

10mpg. And at 10mpg, to suddenly start getting 280 miles from a tankful, when he'd previously been getting only 220, means that he's getting _six_gallons_ more gas each time than he used to. Not very likely IMHO.
Reply to
Doug Miller

snip---------

  1. I think, based on a 93 suburban (e.g. same mfg) with the smaller engine that 16 mpg is optimistic - my suburban gets 16 on the freeway with people in it, traveling long distances but less in town.
  2. thermostat makes a big difference - if the car doesn't come up to temp the computer keeps it running rich - (and it fails smog test) - you can see this in the exhaust gas analysis report - going from a 160 to a 180 deg thermostat made quite an improvement.
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Reply to
William Noble

And it only has a 22-gallon gas tank?????

Reply to
Doug Miller

I do not run out of fuel, I simply get to the point of fuel needle being at the bottom and low fuel warning.

It did not.

I agree.

I like the suggestion of a different blend of gas, personally. (change from winter to summer blend).

i
Reply to
Ignoramus11166

Yes. I would like to have a bigger tank.

Reply to
Ignoramus11166

that would be a double whammy in California...

I wish I could test that speed, that little engine maxes out at 70 mph. But at 60-65, 40 MPG seems to be the norm. And that is quite a wind load.

cheers T.Alan

Reply to
T.Alan Kraus

Sadly, no.

Reply to
Pete C.

I would love to see those studies. In all of the studies and tests I have seen adding alcohol decreases the mileage. Even the folks pushing ethanol admit to that.

Reply to
Steve W.

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