davidv

iTrader: (2)

Keep in mind factors such as...

Ambient temperature about 60 degrees
windows up
heater OFF
Tire pressure 37psi
tire rolling resistance (some tires are better than others)

i8acobra

iTrader: (6)

Look at their average speed... 69MPH. I'm lucky if my average for a whole tank is over 25 MPH. Damn Vegas traffic. I usually average 17-18 mpg.

sharples2

My civic gets 380 off of a 11 gallon tank. Cant wait to get the Z in the spring/

Quijano187

iTrader: (3)

For the last two months i've been trying to get better gas milage out of my car.
I read this thread about two weeks ago and I changed some of my habits and you know what, it worked.

At first at was lucky to get 300 out of my tank. First thing I did was change my spark plugs, i had 69k miles on them and they were disgusting. Second, I make sure my tire psi is at 36 or above cold. Third i use criuse control all the time on the highway now. Someone metion it before but I wanted to confirm that anything over 70miles , you'll lose mpg. So knowing that, I first tried doing 68 to 65 mph on cruise. At that mph i was getting 26 to 28 mpg on average.
ON a full tank while maintaining this speed I was getting 375 to full tank to 385. So i decieded to do 58 to 60 mph hour. This is were I had the most mpg on my car. I was getting 30 to 33 on avg. So i finnaly broke the 400 mark on a full tank.

Now this is only getting to E somtimes showing little milage left. not showing ---- this yet. So today decieded to, "Go for it". Someone said thier tank has 3 gallons on reserve, so I decieded to go another 60 miles . When i got to my destionation , i had 459 miles on my car. I filled up and I Put 19 gallons in my car for the first time!

I drive about 160 miles a day. And i deal with traffic at lest 20 mintues a day
so i know my car can do more if i dont hit traffic. I will hit the 500 mark soon!

I also do other habits that I know haved help with milage. I make sure i dont turn on and my off make car all the time during the day. Like if i got to the gas station for 2 mintues ,ill leave my car on. If go to pick my girl at her house , ill leave my car on. I notice if you turn your car on and off a hundred times on one tank, it kills your gas.

Last time but not least, I feel it's the most important, is what brand of gas are you getting? I feel that most mom and pop gastions are garbage becasue there more water in there gas then other than say "Mobil". I'm always looking for a better deal. When i fill up, I always check the DTE to see how much my car is saying im going to get. Ive gone from 350 to 470 readings in my car in the last two months. Now im not saying "Mobil" is the best becaue i believe its different from gas station to gas station. The mobil near me has always gave me great mpg but the mobil next to the Holland tunnel always give me ****t& mpg. You can tell when you have bad gas casue you car does not respond like it always does.

I hope this have help anybody thats looking for better mpg on their car. God knows gas prices is dumb high and know one likes to **** money away ..

thepostman

its good to know there is someone else out there that is trying to figure out what the the total miles before running out is other than me . Nissan dealer confirmed that 3 gallons is the amount left in the tank once the light goes on. However, I'm thinking that 3 gallons is left in the tank once the DTE goes "---" (see my reason below).

not sure about the spark plugs, I think the overall best mileage you will attain is the highest gear at the top speed which would be probably 6th gear in 40-45 mph. However, if you faster ie: 55-66mph I found anything over 65 will start to have a negative impact on mpg. CC is definitely your friend, I try to get to the top gear as fast as possible. I tend to use 1-3-5-6.

On the freeway (flat, dry) i reset my mpg computer and it stabilized at 31.4 mpg going 63 mph.

Personally, I always go with namebrand gas ie: Chevron simply for additives and I suppose "better" quality for whatever that is worth. as i mentioned earlier, I maintain religiously air pressure cold @ ~75 deg 38 psi on all fours.

The latest in my saga of logging all mileage information:
-------------------------------
total miles driven: 463.4
mpg: 25.5 @38 mph avg
gas filled: 17.68 gal
* I drove 73.6 miles after the DTE "----" came on (used 3 gallons right there and still have 1.5 available assuming the fuel sensor is correct)
-------------------------------

With only filling up 17.68 gal, I should be able to drive safely 1-2 more gals more before filling up which put me at ~500 total miles driven on one tank. I think in the next couple fill ups I will be able to dial in exactly how many miles (avg) I can drive to pump 19 gallons in. I have NEVER pumped in more than my recent 17.68 (I checked all recepts for life of vehicle). I now have a gas can that is filled with 1.5 gals that I will keep in my car as I approach 450 miles just in case. yes, i realize running out is very very very bad for the electric fuel pump. however...this is something I need to figure out bc NO ONE has an acceptable answer to give me (especially Nissan) and I think I can get pretty close without using the gas can.

The funny thing is that until the last 4 months I filled up every time the gas light turned on at ~325 miles. Thats a 175 mile difference (500 - 325 miles).

Some of you may be saying..damn postman are you OCD or what? Well, I live in the crappy state of Oregon. One of only TWO states in the U.S. (NJ is the other) that the law does not allow ppl to pump their own gas. Because of this ridiculous pathetic law (effort to create jobs in a depressed state), getting gas is a frickn event. You basically need to plan when you get gas bc it could take 3-4 times longer than self pumping. I tried pumping gas myself bc the 1 person attendent managing 16 cars was taking way too long, but Chevron has a keypad lock with a pin. argh. I hate everything about oregon (gas law, speed limits, no merging rhythm, excess debris and rocks on freeway) and can't wait to get back to california next summer. (k..i'm done venting).

USAwaterskier1

iTrader: (1)

haha i get bout 350 to the tank. I try to go easy but i just can't...everytime i fill up i am like i need to try to get some good gas mileage and that lasts for about 200 miles. then it is game on

Quijano187

iTrader: (3)

The only reason i changed my spark plugs cause i was starting to get worst and worst perfomance and gas miliage.

I get to about 375 on a full tank lately and then hit E with about 45mls flashing. THen i got 459 miles on tank. Filled up with 19 gallons.

I think i can get 500 and keep like that if i baby it and not hit traffic alot with the things ive been doing.. Ill keep you guys updated!!

hgill

iTrader: (1)

i get about 330from a tank

Z_Driver

iTrader: (3)

This is my same exprience. However, I run 36psi front 34psi rear

I do have iridium plugs, popcharger, and grounding kit as well.

thepostman

after 7 systematic trials over the course of 3 months, i finally managed to run out of gas this morning and filled with my emergency 1 gallon to get me to the gas station. I drove 72.3 miles after the gas light went on which is about 3 gallons (25 mpg *3 gal = 75 miles) which makes sense. I actually was expecting to get to 500 miles but I must have done more surface driving than usual this trial. I usually do 80% highway/20% surface. I'm relieved to finally have definitive information to how far i can take the Z with my driving style and am happy to not be carrrying the emergency gas tank with me anymore!

---------------------
total miles driven: 486.2
mpg: 25
mph: 40
gas filled: 18.91 gallons
miles after gas light: 72.3
---------------------

18.91 + 1 gallon = 20 gallons!

Based on this last data, I am thinking my fuel sensor is correct and that I am simply getting great mileage with my style of driving!

Jun

iTrader: (45)

lol, so i'm not the only one to try this, glad to know!

i believe i got 19.6gal. if i remember correctly...(+ the fuel in the lines and stuff).
Even though my needle never points to full, i know there are 20gal. in there.

y_b_lamron

I usually average 17-20mpg. *sigh*

The other day it saw 26.8 though

bailey bill

I certainly respect people who actually research a question, and then share correct information.

But just FYI, I made the same determination you did with basically one "study" and without carrying a reserve supply and running out of gas.

I calcualted my MPG at each fillup for about 5 fillups. 22.5 to 23.5 for my normal driving. (That also confirmed that the "computer" was pretty accurate.)

So I already knew the tank was 20 gallons, so determining my actual MPG allowed me to calcualte the effective range of a tankfull (22mpg X 20 gallons = 440 miles.

And by filling up when the light came on (approx 17.5 gallons) I knew there was approx 2.5 gallons, or approx 55 miles left.

Again, I'm certainly not criticizing your method and findings, just alerting other owners that they can gather the same infor without having to run dry.

Good info, thanks.

bill

UsafaRice

When I was still in Colorado Springs, I drove it for 506 miles on one tank. I've also played the game like a GM transmission and shifting 1-2-5/6 or 1-3-6. That said, I think that's probably bad for the shifter forks in our transmission.

On another note, my Z weighs about 250 lbs less than most from all the lightening and titanium exhaust and all. It's lowered as well (this makes a huge difference) with the forged Ray's wheels. Whenever I drive between Texas and North Carolina, I average something around 29-31 for an average speed of 80.

Finally, remember that our fuel pump is cooled by the fuel in the tank so technically, using up most of the fuel means you're running it hotter and possibly leading to an earlier failure. My friend's 1997 Corvette has gone through 2 fuel pumps and I suspect that's the reason.

thepostman

that's too funny! i kept pushing it bc i kept getting mixed answers from people including various nissan dealers and I had to get a concrete answer for myself.

thepostman

thanks for that point. After months on this thread researching this topic I found at least 3 different people that ran the tank dry on their quest for validated info. my logic is that everyone drives a certain style and maintains different aspects of the vehicle (ie. tire pressure). With my driving style (80% highway/20% surface streets) I needed to figure out what my limits were exactly on the vehicle.

also, in retrospect I think its actually unsafe to drive until the tank is dry depending on traffic/road conditions etc and I don't suggest it to others. This morning it was raining hard on a two lane highway going 63 mph on CC and it cut the speed and started to stall when i finally ran out. i was on the shoulder safely with hazards so it worked ok for me. i definately wont be taking it that far again (due to electric fuel pump)

Using similar logic as yours I figured avg 25 mpg * 20 gal = 500 miles which I thought was attainable...it turns out I got to 486 so I must have been doing more surface driving than i thought... also i drove for 75 miles with the gas light on which is 25 mpg * 3 gall = 75 miles which confirms my talks with Nissan that once the gas light goes on 3 gallons are left.

The bottom line - my limit was reached at 486 miles @25 mpg. In the future I will fill up regularly at 450 miles (assuming similar driving conditions). it's nice to know in ideal conditions (flat road, no rain, cc ~63-70 mph) that I could likely go 500+!

Thanks everyone for your insight and feedback on this thread!

thepostman

interesting. I've heard from various sources that the only way to incur damage to a fuel pump is if it lacks lubrication which is fuel. no fuel means air is getting into it which is obviously bad. thus, as long as fuel is in the tank and running it is lubricating the fuel pump and no damage of any kind is happening. can you elaborate?

The Mike

I can answer this question. From a full tank *20 gallons if you didn't know, but the yellow light seems to come on when you are about 4 gallons to empty* .. So from a full tank and driving it to Austin 85~90mph and back to Houston and then all over the place across town and such, I finally got stuck *out of gas and wouldn't start* at the library and I reset my tripometer every fillup. I got 420miles on 20 gallons. that's mixed highway and also a ton of stop and go in Houston city traffic. = avg 21mpg

bailey bill

Actually, the pump is cooled by fuel flow. And when the flow stops, the engine stops, and the pump shuts off.

Running the tank dry will NOT damage the fuel pump.

bill

Doc25398

iTrader: (5)

I can usually get 500 miles out of a tank, while barely driving it for 10-15miles with the light on, so I assume I am still keeping it in a safe range for the fuel pump. But I have a plenum spacer and a popcharger, not sure if it eases the cars ability ot make power by using less fuel.