Gas Mileage vs performance

[tdr1919]

I know most of you will get a real howl out of this one! Most mods are for high performance gains, but my 86 gets about 17 mpg (as per the avg mileage guage). This is for highway driving (not hard) Is this considered good ? or can I get it into the 20's?
thanks,
Tom

 

[vetteboy86]

On the highway with the top down about 24.5. With the top up on the highway it is about 1 to 2 mpg better. Everyday driving which is a mix of city, and country. I am averaging about 18.


Craig

 

[G Winter]

My 90 vette gets about 22 on 15 mile runs with an occasional 50 mile run. My average milage indicator is way off tells me I get over 30 so I figure it out the old fashion way. Yours could be off too. I have never gotten less than 18 mpg. but mine is also a 6 speed . The best I got was 28.6 on a 186 mile freeway run at 75 mph. That was with no stop and go at all.

 

[6 Shooter]

I'd think you should get in the mid 20's . . .

Do you know if anyone has ever did any tweaking on your Corvette?

 

[OLDCHEV]

With the top up & down for the last 2500 miles in town (wife drives to work daily in it) my 90 Vert averages 26.9! On the open highway it is better. My lead foot on the weekend still gets 24.5.

 

[OLDCHEV]

My mileage computer matches my gallons vrs miles exactly so I can really rely on the range indicator.

 

[G Winter]

I think mine has 4.10 gears in it so that effects it some I am sure. They may have been change which maybe messes up my trip computer. ???


5500 rpm in 4th is only 95 mph 60 mph in 6th is about 1700 rpm

 

[Renes86]

Our 86 gets 21.5 mpg. Auto trans. That's city and highway average.

 

[tdr1919]

I found that the previous owner removed the service engine soon light, maybe it needs to have the O2 sensors changed, there have been no modifications to the engine

 

[RedRagTop]

On the highway with the top down about 24.5. With the top up on the highway it is about 1 to 2 mpg better. Everyday driving which is a mix of city, and country. I am averaging about 18.


Craig

Same, if not slightly better.

 

[RedRagTop]

I found that the previous owner removed the service engine soon light, maybe it needs to have the O2 sensors changed, there have been no modifications to the engine

Heh heh. That's one way to get rid of that irritating thing. You should hook up to an OBD to see what you've been missing.

 

[larry bud]

I would be surprised if you've done mod and your MPG on the computer is right. Calculate it out over a couple of tanks and compare.

 

[c4cruiser]

There's always a chance that the fuel economy system amy be getting bad readings. Fill the tank so that the handle shuts off automatically and don't force anymore fuel into the tank. Reset the trip odometer to zero. Drive normally until you're down to a 1/4 tank and refill at the same station and the same pump making sure that you allow the handle to shut off in the same way. Compute the mileage from the amount of fuel you added and the miles on the trip odometer. Then repeat and average the two MPG values.

If you can, take an extended trip on the freeway and fill up right at a station at an interchange. Use the cruise control as much as you can and stay at the posted speed limit. Fill up at a freeway station and compute the mileage as above.

My slightly modded 87 (ZZ3 cam, port and polish, balanced, and intake runer port matching) with 4+3 and 3.07 gears will get about 25MPG on the highway and 17-19 in town if I don't drive hard.

If I leave the instant average MPG display up while cruising on the freeway on level ground at 70MPH, the display value will usually hover around 27.

With no SES light bulb, I would drop by a AutoZone to have them check for any codes. They'll do it for free and if there is a O2 sensor that's bad, you should have a code set. Write down any codes that are set and then have the codes erased. Install a new SES bulb and drive until the light comes on again then re-check the codes. IF the O2 code returns, then replace teh O2 sensor and check fuel mileage again.

 

[boomer]

I'll get about 17-18 in my stop and go work commute through the city. On the highway, it'll be in the mid-20s, depending on speed of course. I once broke 30 for a couple tanks along a 1000 mile trip (of course, we never broke the exact speed limit, as I had no registration and plates from my previous car on her ).

Oliver

 

[Randy Eads]

c4cruiser said "Use the cruise control as much as you can and stay at the posted speed limit. "

... is that possible??

 

[G Winter]

Randy... with your wife sitting beside you it is .




Glenn

 

[ZRGator]

I can't even believe we're having an MPG conversation about Vettes!

You want gas mileage, trade in your Vette on a freakin Prius

 

[tdr1919]

Hey , I never thought we'd go 2 pages on this topic!

I can't even believe we're having an MPG conversation about Vettes!

You want gas mileage, trade in your Vette on a freakin Prius

It really should have been put differently, but lets face it, you do not want the car to just be burning it up, you want the most efficient use of the fuel, and at
17 mpg I do not think my car is running efficiently!
Tom

 

[G Winter]

I didn't buy the vette for milage, but really impressed with what it does. I had a 98 Riv. with the supercharged 3800 v6, best I ever got was 24mpg.
To have the best of both worlds is really great . Might as well brag about it . :cool

 

[hAZcAT]

c4cruiser said "Use the cruise control as much as you can and stay at the posted speed limit. "

... is that possible??

I did that once, got 28 miles to a gallon........... crazy