Sudden (apparently) decline in gas mileage?

[nfpgasmask]

Thats nuts, I get around 350-390 miles per tank, depending on fuel quality and speed, and I got somewhere around 165,000 miles.

I've never seen more than 250 miles per tank. 350 would be a dream.

Bart

[CoastieCosta567]

Last Feb. i hit a personal record score of 20mpg, no lie, my wife was there and saw it, we where shocked but have never seen it that high before and today still haven't. But that was due to the fact that i was driving down hill the whole way from the smoky mountains. Its possible that people get those mpgs, the worse I got was 9 mpg, but that was cuz there was a plug in the engine compartment that was loose, and every time i hit a bump the car turned off, took me 6 months to figure out that it was a small and simple fix as just connecting the plug back on correctly. Worse part was that i drove cross country from florida to california like that back in 2007, gas was not that bad though, thank God. My only guess for that issue is that i think the mechanic that saw the VX before i left unplugged something by accident or worse on purpose. You might want to check all your plugs, it could be something that simple. The plug that affected my mpg was the main wire harness that is inside the engine compartment, next to the right fender, there is 3 big-o plugs one over the other, the plug that was loose on mine, was the bottom one, and that one had my temp. gauge off when the plug was not plugged correctly.

[89Vette]

The only other difference I can think of is fuel quality/octane -- as mentioned. Do these people getting 300-400miles/tank live in other countries/areas where fuel is just WAY better?

Also, I looked around again. It seems consistent that the stoimetric point of ethanol is 14.1 (vs 14.7 for gas). That means, for 1 part fuel, it takes 14.1 parts ethanol for complete burn. 14.7 parts gas for complete burn.

Switch that around and it takes 14.7/14.1....about 1.0425 (4.25%) more ethanol than gasoline. But that doesn't count for energy difference (and the amount of throttle) necessary to roll the vehicle along. IIRC, Jerry Lemond was saying 10% loss -- which I thought was a little exaggerated. 5% is what calculations imply. If it's less than 2%, none of us should be getting much less than the 15-19mpg that was the EPA measure for the VX.

Actually 22gals x 19mpg = 418 gallons possible for a tank of gas. Obviously, that would be for a highway trip. It seems pretty bad that many of use are in the 250mpg range, don't you think?

Sorry for the ramble....

[circmand]

The only other difference I can think of is fuel quality/octane -- as mentioned. Do these people getting 300-400miles/tank live in other countries/areas where fuel is just WAY better?

Also, I looked around again. It seems consistent that the stoimetric point of ethanol is 14.1 (vs 14.7 for gas). That means, for 1 part fuel, it takes 14.1 parts ethanol for complete burn. 14.7 parts gas for complete burn.

Switch that around and it takes 14.7/14.1....about 1.0425 (4.25%) more ethanol than gasoline. But that doesn't count for energy difference (and the amount of throttle) necessary to roll the vehicle along. IIRC, Jerry Lemond was saying 10% loss -- which I thought was a little exaggerated. 5% is what calculations imply. If it's less than 2%, none of us should be getting much less than the 15-19mpg that was the EPA measure for the VX.

Actually 22gals x 19mpg = 418 gallons possible for a tank of gas. Obviously, that would be for a highway trip. It seems pretty bad that many of use are in the 250mpg range, don't you think?

Sorry for the ramble....

The government mpgs have very little to do with what you can expect. They allow you to add mpgs for a hybrid that you will never see. A lady recently sued Toyots because she never saw half the mpg the government allowed them to claim. I think the tank is 21 gallons. Also I don't know about you but I never get the tank completely empty before I refuel.

[89Vette]

The government mpgs have very little to do with what you can expect. They allow you to add mpgs for a hybrid that you will never see. A lady recently sued Toyots because she never saw half the mpg the government allowed them to claim. I think the tank is 21 gallons. Also I don't know about you but I never get the tank completely empty before I refuel.

I saw the story about the successful complaint against Toyota. Bravo!

The tank is 22.5gal according to this forum's knowledgebase...
http://vehicross.info/modules.php?na...warticle&id=29

How low (much) fuel you burn before refilling is a good point. Because of these goofy, bouncing gas gauges, some might consider it empty at 1/4 tank. Others might blow it til fumes.

Mine has 16" wheels w/31" (street) tires -- which I thought would raise mpg. Maybe it doesn't. 4:30 gears seem awfully steep for optimal MPG.