Problem: Suddenly better gas mileage

Do check your oil and coolant levels: if, for some reason, you're buring either of those, you will see an increase in fuel economy. Otherwise, could be that the low-fuel light is coming on later than it used to, could be a perception issue, could be a change in the formulation of the gas. If you're not losing oil or coolant, then there's no real problem.

good luck! GTr

Doug Kanter wrote:

Most of the vehicles I have owned recently have had the gas mileage improve slightly with age - maybe 5%. But you are suggesting a 13 to 17% increase. This does not seem reasonable. Is it possible that the formulation of gas in your area has changed over the last year? Trying to compare mileage by comparing miles per tank is not very accurate, so it may just be an aberration in your memory or in the way the tank fills.

Ed

Doug Kanter wrote:

Maybe your truck has finally gotten broken in.....

This might work if you can park at the same pump in the same spot. However, even small differences in the angle of the truck can make large differences in the amount of fuel the tank will hold. You are far bett off averaginfg the fuel economy over a larger number of tanks of fuel to reduce the effect of thiss error as much as possible.

Ed

Formulation may be the issue. Memory is not. Written notes are the basis of these numbers.

All fluids are at proper levels, and clean. Always. The engine seems to use absolutely no oil.

Was the driving during the same time of year? Some areas (I'm told) will add different things to the gas depending on season. I noticed a very big difference about the time my local station went from their winter formula to their summer formula (basically, got crappy mileage and engine performance after religiously using their gas, called them up to complain and they said it was that they'd changed the additives for the season... not sure whether that's a load of B/S or not...) I've noticed some tanks I'll get 230 miles before I fill up, and others I'll get 320 or better, but mostly because it's a matter of how nervous I am I'll run empty before I near a station. ;) I'd have to check my log book for the actual seasonal mileages.

--Dee-- ~Remove all preflight tags before replying by email.~

Why would you do all that? Reset your trip meter at the gas station and fill it until the nozzle clicks off. Drive however far, half tank, whole tank, whatever, and go back to get gas. Divide the number of miles on your trip meter by the exact number of gallons you refill with at that time until the nozzle clicks off again. Why the hell would you need to do all the other crap. Basic math, man.

Sincerely, Mastiff

Yeah....this is how I've been measuring, sort of. I wait till the warning light comes on. At that point, every fill-up takes 15.5 to 15.9 gallons. Then, I averaged many instances. Obviously, this isn't like having an in-line fuel flow meter, but whattyagonnado, ya know? :-)

I guess I'm wondering why you let your gasoline level get down to where the warning light comes on. I hope the warning light doesn't burn out on you and your gasoline level gets so low the fuel pump overheats and dies.

I try to never get too much below a half tank before I fill up but that's me. You can do what you want.

Good luck.

Bearman

2) The light comes on before the needle actually hits the white line at the bottom of the gauge. Based on the truck's capacity vs what the pump shows I'm putting in, I still have a gallon left. If that hurts the fuel pump, then this must be a Chevy with a Toyota label on it.

The warning light is WAY innaccurate. Mine comes on when I have used anywhere from 20 to 22 gallons. Sometimes it comes on and then dims, other times it's solid.

You have to use actual mileage... don't worry about the warning light.

Here's mine:

--- Rich

It's progressive. The fuel pump is cooled by the fuel. Cooler = Longer life, for any electrical or electronic component.

Running OUT of fuel may or may not kill the pump the first time, but it will shorten it's life.

Uhh... my '94 p/u's radiator said "GM" :)

--- Rich

It just depends on how accurate you want to be. There are a lot of variable associated with filling the tank. Doing the average over several tankfuls reduces (but does not eliminate) the error.

Ed

it's your fuel pump failing. I went from 350K's per tank to 450K's and then kapputt!! its not pumping at the necessary psi, so you;re using very little fuel. new fuel pump needed.

At 22,000 miles? And mileage is still just as awful around town as before, but better on highway?