Gas Mileage Issue

[slikaznricer]

hey guys...Im relatively new here so i just wanted to ask a few questions about anyone elses Z31... I recently bought mine as a DD and im fairly happy with it. its got great power(tho its a N/A) and handles nice-ish(shocks are dead). my only complaint is my gas mileage...idk if you guys have this problem.... i put a full tank ~12 gallons and only get about 180 HIGHWAY MILES...what is going on herethat averages about 15MPG HWYis that right?cause my sticker on the car says 26 MPG....then again i have to adjust for todays standards in fuel efficiency but still...thats pretty bad...i changed the fuel filter and changed the spark plugs but no results..what else is wrong?if anyone could help me thanks a bunch!

keep the good work up here on the forums guys...and i envy all those modded Z31's.....i want to be like you....

[88sammi]

not familar wit hthe car but cheack u 02 sensors if those r bad theyll kill ur gas milage

[evildky]

your driving habits play a large role in your results, if you do really drive almost all highway miles and cruise in 5th gera around 55-65 mph then you should get at least north of 20 mpg, faster will give you less as well as slower city drivingclogged cat, O2, CHTS, MAS

and just to be clean you are filling up, with 12 gals then driving 180 miles then filling up with antoher 12 gals? the easiest way to calculate your actual milage is to fill up the tank, reset the trip counter and drive till you are nearly empty, then refil, take the number of miles driven and devide by the number of gallons needed fr the refil, this is your average mpg, if you are going on what the gauge says then that part of your problem they tend to be inacurate, and the sticker was very optimistic in their milage estimates

[AZ-ZBum]

Make sure you're measuring fuel mileage correctly.

1. Fill tank to full.2. Reset odometer.3. Drive.4. Fill tank to full.5. Note miles driven since last fill up.6. Note gallons required to fill car to full.7. Divide.

PS: Z31 fuel tank is 19 gallons.

[George 86na]

I get almost 30 mpg cruising at 75. I can drive from NC to FL on one tank of gas.

[wilber54]

Only 30mpgs? You should be able to get a bit more, what have you udpated?

[AZ-ZBum]

Only 30mpgs? You should be able to get a bit more, what have you udpated?

And what makes you say that? Why do you think we should be getting more than 30mpg?

[slikaznricer]

Make sure you're measuring fuel mileage correctly.

PS: Z31 fuel tank is 19 gallons.

WTF 19 GALLONS?!?!?!?!?!??!?! jesum crow~i fill mine up and it goes to 12.....thats when the needle is on E too!

[AZ-ZBum]

WTF 19 GALLONS?!?!?!?!?!??!?! jesum crow~i fill mine up and it goes to 12.....thats when the needle is on E too!

It helps when you read the owners manual, repair manual, etc. Then you would have known how many gallons the fuel tank is.

Fuel level sending units are common problems in the Z31. Replace it if you want.

[slikaznricer]

i woulda read it but the previous owner didnt include them with the car....makes me sadanyway fuel level sending units?where can i get one of those?cause my needle goes to E when i use 12 gallons and then theres another thing at the bottom thats supposed to start when the tank is 1/4 to empty but i hav e never seen that work...poopie...my car hardly works at all...

EDIT: your site is SICK nice info!

[evildky]

a lot of older cars tend to have very inacurate fuel gauges, if you know the volume of your tank, and your actual average mpg you can have a fairly good estimate as to ho wmany miles you can get on a tank of gas, just reset the trip counter when you fillup and you'll have a fair idea as to how far you can drive between fillups

[AZ-ZBum]

i woulda read it but the previous owner didnt include them with the car....makes me sadanyway fuel level sending units?where can i get one of those?cause my needle goes to E when i use 12 gallons and then theres another thing at the bottom thats supposed to start when the tank is 1/4 to empty but i hav e never seen that work...poopie...my car hardly works at all...

EDIT: your site is SICK nice info!

Yes. Fuel level sending unit. It's in the fuel tank. It sends a signal to the fuel gauge to tell it how much fuel is in the tank. You buy it from the dealer. You can try cleaning it, but that rarely lasts if it even works.http://www.zeeyalater.net/comprob1.htm#fuel%20unit

Well... The little gauge is for E to 1/4 tank. And 1/4 of 19 gallons is 4.75 gallons. So the needle should only appear when you have between 0 and 5 gallons. And since you're only putting 12 gallons in the tank, 19 minus 12 is 7. So since 7 isn't between 0 and 5, you probably won't see that needle.

Do as evilky suggests and just fill the tank full and watch the mileage. Or, you can continue going off the fuel gauge and realize you'll never run out of gas. I use the trip odometer method.

[Pharaohabq]

and get a gas can. walking sucks when you know your Z is sitting by the side of the highway all alone and scared....