problem with gas milage

[gassucker]

hey yall, i have a 78 chevy long web with 350 automatic motor. i got it all primered and running good so i drove it to town and back total trip was 30 miles the truck was on full and when i got back home it went down 3 lines. does that seem like its using alot of gas? just wonderin maybe its me im used to driving a mini truck.

by the way this place rocks

[Tom]

3 lines as in 3/4 of the gas gauge? Yes thats super exsessive. You would have just used 12 gallons to go 30miles.

[Prerunner1982]

there are smaller lines than that.. 3 lines on mine would be 3/8th of a tank. that still seems like alot, to go a 100 miles to school and back my truck would use 3/4s of a tank and thats with a 350, th350, 31"s (at the time) and 3.08 rear end @ 70mph.

btw welcome to our addiction!

[gassucker]

thanks! yea its on 3/4 line. could it be somtin with the carborator out of tune or somthin? or the fuel pump or hole in the hose?

[KShortell]

What you need to do is to keep a fuel and mileage log. That's the only accurate way to measure your fuel consumption. Gauges can be inconsistent in the rate at which they change. Some start going down quickly and then slow down, others just the opposite. Yours may drop quickly at first, then slow down. I suspect that this is the case.

Good luck!

[Grim Reaper]

Originally Posted by KShortell

What you need to do is to keep a fuel and mileage log. That's the only accurate way to measure your fuel consumption. Gauges can be inconsistent in the rate at which they change. Some start going down quickly and then slow down, others just the opposite. Yours may drop quickly at first, then slow down. I suspect that this is the case.

Good luck!

Yep. These gages are not acurate. Both my 75 K5 and my 88 Burb will stay on full forever then start dropping fast. 3/4 of a tank on the 75 Jimmy is really a 1/2 tank. once it gets down to a 1/2 tank its only about 5 miles till empty. The truck will go 300 miles a tank.

Burb is the same way just not as severe.

First thing is verify the Odometer is acurate and then keep a log. My 88 is dead on For the odometer but the speedometer reads slow. My 75 reads less then actual because of tire size changed. The POS Honda bomb has the wrong sized tires and it adds 3 miles every 100. I used a GPS and it's trip odometer to figure mine.

[gassucker]

thanks guys, im gonna keep driving it and see if it does any better! sucks about the guages not being accurate though

[1FaastC10]

Originally Posted by Grim Reaper

My 88 is dead on For the odometer but the speedometer reads slow.

that's not possible, both are driven by the same cable.

[NeCrOmAnCeR]

The odometer is driven directly from the cable (through direct gearing) while the needle is driven by a spinning magnet. (eddy currents) If the spring tension on the "clock" spring is to high, or if the bearing is sticky etc, the needle will read low. The opposite can also happen if the spring tension is to loose.

[gassucker]

i have an eldelbrock carb, do u think if i put a stock carb on there and changed air and gas filter think it would help some?

[1FaastC10]

the Quad would give you better milage, and better performance if rebuilt and tuned properly. changing the air and fuel filters can never hurt.

[Grim Reaper]

Originally Posted by 1FaastC10

that's not possible, both are driven by the same cable.

Sorry, but in my void in the world it is not only possible it happens and I can document. Your more then welcome to come ride in it and I'll hook up my Garmin GPS V with roof mount antenna that is usualy accurate to within 10ft. The Miles are confirmed over a 200+miles of get in and drive non stop. It was off by less then 1 mile on the odometer and the speedometer read off by 4mph at 60.

[screwballl]

i am averaging 15mpg with my tired old '76 350 so it does suck it down

[SanitysBane]

i get about 12 or so with my rebuilt big block 454 on city driving, 10 if i get on it alot...