Now I already know there is a gas mileage thread but I want to start my own.

Over the past few weeks, ?I've been trying to increase my gas mileage, anbd I just want to know what some of you guys on here are getting per tank, per gallon.

Last fill up, I ran her dry right into the gas station and filled her up with 15.3 gallons in a 15.5 gallon tank, it was completely full, 15.5 gallons to my best estimate based on my calculations.

At half a tank, I had traveled 262 miles, half tank being the needle as close to completely centered in the gauge as I get read it.

So 262x2=524 miles

Then 524/15.5=33.80mpg

My last greatest mileage was 32.6 last summer so I'm confident in these numbers, and I've ran them again and again and calculated the mileage when it started to dip below full, and when it was at 3/4 tank. Everything is consistent!

I'm so happy that my mileage has improved, when I first started to commute everyday like I do now, I was getting around 25-25, but now I can make my gas go further.

So, can anyone top 34mpg?

-Stats
1990 Chevrolet Camaro RS
3.1L V6 73,336 miles(as of posting)
Automatic, 3.23 gears
5w-30 Mobil-1 Synthetic blend oil

 

50 mpg kidding, thats only an import.......

 

Well hey man you have the same car, what kind of mileage do you get?!

 

honestly i don't know, shes been sitting since i bought her so i dont know

 

Oh, did you just pick her up?

 

I wouldn't judge based on the fuel gauge.
In both of my Birds, the gauge has stayed in the top half of the dial forever, then drop like a rock.

Best way to measure fuel milage is to fill the tank, right your milage, drive till the light comes on, fill up and note how much gas it takes to fill. Divide your miles by how much it took to fill up.

 

Do you guys really have gas lights? I don't have one, or so I thought. I guess the bulb could be burned out? I just never knew I was supposed tohave one

 

Thats what I'm going to do in the end, but right now based on my calculations, everything points to 30+mpg, and to my best calculations and how I've seen the gauge move and act in turns and hills and level driving, its getting 34 or somewhere really close to that.

Before I had it at 33 over the life of a tank, so I'm hoping that this turns out just as good if not better.

 

Best way I know of:
1. Top off tank
2. Reset trip meter
3. Drive down to 1/4 or less
4. Top off tank and make note of miles and gallons to top off.
5. Divide miles by gallons. 360 miles / 13 gallons = 27.69mpg

If I remember right, back when I was getting 28 all the time, I was usually at about 250 miles at the half mark.

 

Yeah, so 30 would be a good estimate I guess, if the gauges were more accurate though and could be trusted a bit more then I would be getting what I calculate the car to be getting. I'll be able to tell here in a few days, all I know is that it has to be getting around 30 FOR SURE. Anything more and I might be pushing it, I guess I got excited about getting such good mileage

 

Took me 5 years to gain 3 MPG... And about $1500, but that's another story. I think it was 400 miles on almost 12 gallons of gas, and that was only once, when the MAF was actually working.

BTW, half a tank is actually 1/3 of a tank due to the shape of the tank...

Sounds like some people on here do mostly highway driving. And no, there is no fuel light on a ThirdGen.

 

Oh, I didn't know that the shape of the tank could affect it that much...and yeah I know theres no fuel light on our cars.

By the time I had run the tank about empty, the trip meter had 418 miles and I put just under 14 gallons in the tank, it was something like 13.946 gallons but that was all the further I dared to drive it with no extra gas in the trunk.

So 418/14=29.85mpg

So I guess Dr.NickRiviera was right, I never noticed, over the top half of the tank the gauge stays and when it gets below it drops like a rock, or at least thats what the calculations point to, because the half tank average was 34mpg, and the whole tank average was about 30, which is still amazing.

That doesn't go to say that at points my mileage was higher or lower because we are only calculating the average, so who knows what the cars are really capable of getting on a nice straight highway with easy turns and no bumps

 

36mpg avg sometimes i see over 40mpg depending on the tune i run
and this on a heavily modified 3.1

 

My baby's completely stock Well, ok....I do have a K&N Air Filter

 

WTF man i can barely get 220 to the tank and that's a good day.
........

 

man wtf are you guys running? I barely get 18mpg like seriously.

 

99% stock spec 3.1L, only mod: K&N Air Filter.

 

I averaged 26-27 mpg in exclusively city driving back in the day when it still had the 2.8, bone stock down to the DIRTY paper air filters. Didn't ever really drive it hard, no desire to when it's just a V6

 

The big 'gotcha' of this thread is the calculation from a stock gauge at the middle of the tank. As pointed out the shape of the stock fuel tank makes the gauge stay near the top for a LONG time. You've got to run the car down to fumes (generally the gauge reads zero when there's still about 2 gallons in the tank) zero the trip odometer, and then fill up. Drive until you're on fumes again, get gas and divide the miles travelled by the gallons to full and you'll get an approximate MPG. Now this isn't an exact science, because depending on temps, tire diameter, tolerances in the gas pumps, tolerances in the speedometer/odometer/gas gauge, etc there's plenty of room for error.

In November I drove my 91 Formula 5.7L TPI/automatic to Topeka (100 miles) to visit a friend. When I left to come home I zero'd the trip odometer, and filled up with gas. I drove home, put the car in the garage and proceeded to wait out winter. A couple of nice days I took the car out for drives around town, and the gas gauge still showed a full tank. Same friend came here last weekend, and we took the car out. After driving for an hour he asked why the gas gauge had gone from FULL to below half a tank so quickly. Again, shape of the tank...

That said I've owned everything from 2.8's and 3.1's to carbed and fuel injected 305's, to stock 350 TPI cars. On the highway, a V6 usually pulls better gas mileage, but not even 10mpg better then a stock L98. In city traffic, the V6 can get worse gas mileage then the big V8's. If you keep your foot out of both of them, they'll practically get the same mileage. I used to get close to 30mpg with my 305 4bbl on the highway during road trips. There just really isn't enough difference to worry about.