quick question on gas mileage for a 1996

[Ken B.]

A friend and i were talking about the gas mileage differences between my 75 and his 96. Mine has been probably over modified, and gets roughly 13 mpg on the highway. He says that he gets 30 to 33 mpg on the highway. I find that kinda hard to believe. Anyone know what the 96's got ? Just curious.
Thanks

[Bill M.]

Re: quick question on gas mileage for a 1996

Ken:

My '92 will show 30 mpg on the mileage computer while driving on the Xway at 70 mph. It's the overdrive. I shifted down to 4th gear (1:1) and it went to 17 mpg...

[William G.]

Re: quick question on gas mileage for a 1996

I bought a new 96 LT4 that got 25 mpg on the highway in 6th gear. As I remember, 2000 rpm was 88 mph!

[Jack H.]

Re: quick question on gas mileage for a 1996

The newer Corvettes are very fuel efficient (for their HP/weight ratio silhouettes) and the use of integral overdrive transmission technology is one of several key contributing factors...

[Clem Z.]

Re: quick question on gas mileage for a 1996

went on a 400 road trip yesterday in a 2008 ZO-6 with a 600+ HP Katech engine and it averaged 24 MPG and we were running at 75/85 MPH most of the time.

[Terry M.]

Re: quick question on gas mileage for a 1996

My 2008 Z06 got 25.7 mpg (actual calculations, not the computer read out on the DIC) for three consecutive tanks -- with two different drivers -- on the trip to/from Chattanooga. It started with 500 miles on it, so I am not even sure it is broken in yet -- although many claim no break-in is needed.

The modern cars are just incredible, and 1600 rpm at 80 mph has a lot to do with it. On the way back from the National in Monterey (what year was that?) I traveled with some of our members with the then-new cars. The manual transmission cars were getting over 30 mpg consistently at some really rapid velocities -- wide open spaces in Chuck's neighborhood where the speed limit is now 80. One of my chapter mates has a 383 Mallet modified engine in a C6 and he gets high twenty something. His new line to the Prieus drivers is that he did all the mods for the fuel mileage.

[Juliet P.]

Re: quick question on gas mileage for a 1996

My 2002 got about 21-22 for my regular commute, 30 miles hwy, 10 miles in downtown DC bumper to bumper traffic. My 2007 averages about 22 for the same regular commute. On the hwy for long trips my 2007 gets about 30 mpg. If I use cruise control I can often get closer to 32 mpg. My 2002 was about the same mileage as my 2007 is. The 1987 I had before that was a little lower mileage, but not by more than 1-2 mpg. With the excellent fuel economy and creature comforts in the newer corvettes, I don't see the benefit of driving a regular car. So I drive a vette daily. ~Juliet

[Patrick H.]

Re: quick question on gas mileage for a 1996

With the excellent fuel economy and creature comforts in the newer corvettes, I don't see the benefit of driving a regular car. So I drive a vette daily. ~Juliet

Same here. My truck only gets driven on rainy days like today. And, in my family we jokingly refer to my 08 as the "economy car" because it beats the truck, my wife's minivan and, of course, the 3 old cars. All that and 436 hp too!

I'm getting about 18.5 in daily driving around town, and I'm playing around with long stretches of country road to find the "best" mileage speed for highway. From what I can tell, I do better the faster I go when I'm in 6th gear!

The drive to Seven Springs in 2 weeks will be interesting. I'll be trying to maximize fuel mileage as a "game" on that trip.

Patrick

[Duke W.]

Re: quick question on gas mileage for a 1996

Modern engines have very precise fuel flow control, and with detonation sensors can run aggressive spark advance maps that keep the advance in the optimum range for peak efficiency at nearly all engine operating conditions as long as there is no detonation.

Valve overlap is low to modest and power is achieved with good head /inlet manifold flow, late closing inlet valves, and low restriction exhaust systems. Many detail internal changes over the years have also reduced internal engine friction.

Combine the above with Corvette's low weight, good aerodynamics (low frontal area and Cd), and tall highway gearing and you have a formula for good fuel economy.

It seems that many late model Corvette owners are installing high overlap camshafts - big mistake. High valve overlap kills low end torque and fuel economy, which kills in town fuel economy, and may make sixth gear virtually unusable on the highway.

In return they get mayby a modest increase in top end power, and an "aggressive" idle.

Their choice, but IMO about all you can do to a modern Corvette engine (other than some judicious ECU reprogramming) when you start messing with the internals is screw it up.

Duke

[Clem Z.]

Re: quick question on gas mileage for a 1996

Modern engines have very precise fuel flow control, and with detonation sensors can run aggressive spark advance maps that keep the advance in the optimum range for peak efficiency at nearly all engine operating conditions as long as there is no detonation.

Valve overlap is low to modest and power is achieved with good head /inlet manifold flow, late closing inlet valves, and low restriction exhaust systems. Many detail internal changes over the years have also reduced internal engine friction.

Combine the above with Corvette's low weight, good aerodynamics (low frontal area and Cd), and tall highway gearing and you have a formula for good fuel economy.

It seems that many late model Corvette owners are installing high overlap camshafts - big mistake. High valve overlap kills low end torque and fuel economy, which kills in town fuel economy, and may make sixth gear virtually unusable on the highway.

In return they get mayby a modest increase in top end power, and an "aggressive" idle.

Their choice, but IMO about all you can do to a modern Corvette engine (other than some judicious ECU reprogramming) when you start messing with the internals is screw it up.

Duke

all true but have a extra 80/100 HP sure is FUN. back when i was younger i modified every high performance car i ever owned. i would pick up a new car at the dealer and have the engine out with less that 20 miles showing on the odometer. wish i had that much ambition now.

[Terry M.]

Re: quick question on gas mileage for a 1996

I am regularly amazed at the low-end torque of the LS7. It will pull without a hiccup from 900 rpm in 6th gear. I try not to do that -- it scares the dickens out of me -- I am used to low/no torque at low rpm small blocks.

Seeing what passes for pistons in these things is another scary event -- there is NOTHING there. They just took all the mass out of them, and then coated them with a high-slip/anti-friction compound. Mass efficient is the operative term, I am told.

I still can't get over that they can machine both the bore and piston to such close tolerances that Wixom gets eight piston/rod assemblies and it doesn't matter what hole they go into. They are matched for weight, but they can go in any hole.

The whole Wixom assembly building is smaller than the piston-rod area was in Flint or Tonawanda. This is no longer your father's (or maybe grandfather's) corvette.

[Clem Z.]

Re: quick question on gas mileage for a 1996

I am regularly amazed at the low-end torque of the LS7. It will pull without a hiccup from 900 rpm in 6th gear. I try not to do that -- it scares the dickens out of me -- I am used to low/no torque at low rpm small blocks.

Seeing what passes for pistons in these things is another scary event -- there is NOTHING there. They just took all the mass out of them, and then coated them with a high-slip/anti-friction compound. Mass efficient is the operative term, I am told.

I still can't get over that they can machine both the bore and piston to such close tolerances that Wixom gets eight piston/rod assemblies and it doesn't matter what hole they go into. They are matched for weight, but they can go in any hole.

The whole Wixom assembly building is smaller than the piston-rod area was in Flint or Tonawanda. This is no longer your father's (or maybe grandfather's) corvette.

the rings they use are like the rings we used in race engine,very thin to reduce friction. i was just at the wixsom plant about a month a go and we toured pratt & miller along with Katech while up there in that area as we picked up a 2008 Z0-6 with a Katech worked over engine

[Joe L.]

Re: quick question on gas mileage for a 1996

A friend and i were talking about the gas mileage differences between my 75 and his 96. Mine has been probably over modified, and gets roughly 13 mpg on the highway. He says that he gets 30 to 33 mpg on the highway. I find that kinda hard to believe. Anyone know what the 96's got ? Just curious.
Thanks

Ken-----


If he's talking about an INSTANTANEOUS mpg reading of 30-33, that's very possible. However, if he's talking about an AVERAGE mpg of 30-33, I say no way.

My 1992 LT1 will get up to the range of about 25-26 mpg IF a trip is mostly highway driving with little or no city driving. For combination highway/city driving with the majority highway driving, I get about 20-21.

I don't think a 1996 LT1 would be all that much different than my 1992.

[Bill W.]

Re: quick question on gas mileage for a 1996

my 96 lt4 got about 24