I have been wondering why the heck does it seem that I have to refuel so much. So I did a little research and I'm getting around 8-10 MPG . I took the amount of miles I had between refuels and I always ran my tank as low as possible before refueling. I relize that their is a little room for error so I did it multiple times so I could get an average. So like I said according to my figures I'm getting around 8-10+ MPG. I don't drive my car that hard. On average staying around 2000 RPMs so it's not like I drive around pulling 5000 RPMs every where. I have some ideas what might be wrong but could somebody please give me some suggestions. I know LT1's like the gas but come on, it's not like I'm pushing 450 HP either. The pumps are killing me.

 

what are some details about your car?
year? mileage? mods?

my first guess would be you need a tune up. new plugs, and wires. also, you could be leaking fuel, have you replaced the fuel filter lately? maybe you didn't tighten it down, or you could have punctured a fuel line somewhere.

 

Are you saying you took the amount of miles on each tank and then divided by the size of the tank? or are you saying you divided by the amount that your putting in it?

 

Best way to figure out MPG is to fill your tank up completely, zero out your odometer, use up 1/2 the tank, fill it back up all the way and note how much you had to put back in and divide by the miles you logged on your odometer.
Do this a few times to get a good average.

Also, note the gallons you put in, not the $$$ amount.

 

i get like 240 to a full tank....plus my gas gauge dont work, cuase i think my fuel pump sender unit is broken or the lil bobber is stuck...maybei should clean it....who knows..
randy

 

Is your car throwing any codes? Have you changed your O2 sensors lately?

 

i feel your pain.... my old 3.4 94 for some reason couldnt get above 11..... i had full tune up - new plugs wires, fuel pumps filters, egr valve, o2 sensors, gaskets, everything...even had engine rebuilt but for some reason which 5 mechanics couldnt figure out only got 11 at best... at one point was down to 6 but turned out EGR valve got fried....

i gave up and ditched car for an LT1 and get double the mileage almost with a lot more power...

damn the 6 cylinder was wierd

 

Yea i would check the O2 sensor, when those go out you usually get around 10 miles per gallon. So i would suggust you start there.

 

Like mentioned above, you need to be careful with the math. When my car gets down to near the "E", it only takes 11.5 or so gallons to fill it back up. But the tank is, what 15.6 gallons or something? If I get 250 miles on that "tank", I would divide by the 11.5 gallons it takes to fill back up:

250/11.5 = 21.74 mpg

If I do it wrong, and just assume its about a full tank, then divide by the tank capacity, then I get:

250/15.6 = 16.03 mpg. Big difference...

You are trying to calculate how many miles you get per gallon of gas. To do that, you need two measurements: miles traveled, and gallons consumed. The odometer takes care of the miles traveled. The fuel gauge and/or tank capacity DO NOT give good measurements for gallons of fuel consumed. Noting how much gas it takes to refill the tank is the way to obtain that measurement.

 

As mentioned before, the most accurate way is to fill up each time you get gas, and then divide the number of miles traveled since last fill up by the galons you just put in.
Lowest I've ever had was 12.75 and highest was 24. I've gotten into a habit of calculating my mpg each time I get gas.

 

You guys are acting like this guy is retarded and doesnt know how to figure out gas mileage. Im pretty sure he knows how to do it. I think he was looking for ways to make it better.

 

 

I average about 14-17 MPG with alot of what I call "Spirited" driving. Make sure your cat isn`t clogged.

 

1995 Z28 convertible, 75K miles.

Gutted cat, cat back exhaust, upgrade fuel injectors and the pressure is suppose to be at 60 psi (previous did the whole injector thing), Bosh platium spark plugs, and drop in K&N.

 

60psi is WAY too high.... stock is 38psi i believe. (i know it's right around 40)

if the fuel pressure is truely 60psi.... it sounds like the guy wasn't sure what he was doing, and you might want to make sure the computer is correctly calibrated for the upgraded injectors.