This is a function of how gas gauges work.
There a float in ther attached to a lever. WHen you fill the tank, the float is partially or fully submerged and doesn't start to descend until the gas has gone below a certain level so the first miles are like running on no gas.

Now to mileage...I just did a highway trip of about 290 miles, top down, two people, with only one vtec and a bunch of traffic jam stuff. I was in cruise at 75 otherwise and got 29.5 mpg. Normally, I get about 27 mpg.

 

Recent 5 hour trip with cruise control and top down - 29.6 MPG

 

I've heard that newer Vettes get around 30 to the gallon. How is that? I realize that would be figured during very easy driving, but still, all 8 of those cylinders just drinking away.. I'm impressed if they really do get that high of gas mileage.

 

I always guestamate my MPG that way It can help to find out if something is off. I usually get 22-24 mpg however I went to Rochester,NY in the rain and had to drive the speed limit the whole way with no traffic on the roads (ugh that killed me) top up and I did the exact calculation I got 30.145 MPG. I'll probably never see that number again.

 

Someone correct me if I am wrong on this. The current vette gets 28MPG on highway and the new vette suppose to get 30 MPG highway. This is due to the tran on the vette. On highway, you can cruise at 70MPH at around 1.1K RPM.

for my S, i am getting 280 to 290 per tank I do about 70% is highway and 30% city on my S. I don't Vtec my S that much, I think I am getting old

 

Dusty,

I echo some of the other comments. Accelerating reasonably, but running it up to 3500-4000 before shifting probably will yield better mileage, will certainly be easier on the engine, and will be a lot more fun. In addition, skipping gears is hard on the car, especially if you're shifting at low rpm (in addition to lugging the engine, I understand that the synchronizers don't like it, but I don't know that of my own knowledge), and significantly reduces the fun factor.

FWIW

 

I usually get around 250-260 a tank, but I have reached 310 on a tank once! If you want to get high MPG's don't drive it like it was designed to be driven.

 

My last full tank, filled @ 1 bar than again @ 1 bar on the gauge, I got 225 miles for the tank.

 

I was able to get 255 miles one full tank of gasoline, combination hwy mostly and city

 

As an addendum to my previous post... I ended up getting 27.95mpg on my road trip from Vancouver to San Antonio, including 2 full weeks of driving around in Vancouver traffic. I clocked right at 4000 miles including about 600 miles of city driving and still managed just under 28mpg -- quite impressive, really!

As for the newer Corvettes, the reason they can get such good mileage is like somebody said, the engines are barely turning any rpm's whatsoever. I think 80mph in 6th gear is something rediculously low like 1300-1400rpm or so. At 80mph, our cars are turning ~4500 or so, I think. That means the Corvette's 8 cylinders combined are still having fewer fuel injector pulses and spark plug ignitions per mile than our engines.