Sorry, I can’t help myself, I will ask one more time then let t go......


OP

what at is your actual mileage? as calculated by dividing miles driven between fill ups and gallons pumped to bring back full,
the ars gas gauge has nothing to do with this, you may not even have a problem.....if you did it would probably exhibit in more ways than MPG like throwing codes and lack of power. Just a thought

 

01/07 130357 346.1 14 23.9
02/14 130628 324.2 13.9 23.3
03/04 132578 306.1 13.0 23.5
04/06 133757 255 11.5 22.2
How about from my gas log for the 1st fill up of the month of this year? Stock with Corsa Exhaust , Auto '03 Coupe. Mostly ethanol regular and all around genital cruising.
Date Total mileage Miles at fillup, Gallons put in till full, Miles per gallon.

 

Be careful out there!

 

Coming off over 400k miles of motorcycle travel before having to quit long distance travel due to a crash avoiding a deer in the W. Texas mountains, I still drive with a motorcycle outlook on trusting others on the road. LOL. The wife was really glad when I got into Corvette a few years back. My 2018 figures were '00 Kawasaki KLR 650 > 980 miles, '03 Chevy Truck > 2736 miles , '07 Suzuki 1250S Bandit > 7461 miles and the Lowly '03 Corvette Coupe > 13489 miles . Really do love cruising about in the car. Back farm roads,. cruise on, music on. enjoying seeing what happening with the farmers and life in the country. ;-)

 

I drive mostly highway, which is covered in traffic half the time. I get right around 20mpg. Did a trip to Vegas from San Diego a few weeks ago and was about 28mpg though! Plus i got to take her up to 150mph finally.

 

You guys getting the 20+ mpg on stock tune?

 

Don't see anything in my records since my car left the factory in June of '02. So, factory tuned?

 

Mine is.

 

It isn't worth much. I've tried 2.0L and 5.3L engines at 15:1, 16:1, 16.5:1 sometimes 17:1

and there is very little to be gained.

Factory timing is already 40-45 heck I've seen 50* in some engines for cruise.

There is nothing left to 'tune'
Believe me when I say the factory has already done 99% of all the easiest most obvious stuff to bring that window sticker number down for the EPA and to compete with every other car who's had the same thing done.

 

Using 6th gear? I forget 99% of the time about 6th gear and most of the time I only use 5.

 

I disagree. You may be correct when the engine is warmed up and you are up to highway speeds. But when you were talking about a cold start up until the engine is warm, basically the first 5 minutes the stock tune wastes fuel something terrible. Just watch your D I C instant mileage until it goes into closed-loop and the temperature goes above 180. It's drinking fuel, and unnecessary.

 

Cold start only lasts a few minutes. Like 4-5 minutes.

If you drive for an hour, the first 5 minutes is negligible.

And if you 'tune it out' which basically just means removing that 20-30% extra fuel for the first 5 minutes (when the car should be sitting near idle anyways) It will drive like **** for that 5 minutes.
The fuel savings is negligible again because at idle speeds the engine is using the least amount of fuel possible.
So 30% extra to a "minimum quantity" is essentially nothing.

 

I wouldnt change the rich nature of the cold start for anything. Makes great gargles when taking your foot off the gas at 2-3K RPMS. Worth every penny!

 

My drive to work is 5m30s. It's important. Especially in a thread where the guy is asking what affects fuel economy. Furthermore, I'm not at idle. I'm talking about being up to speed. I live 200 yards from the onramp and work 400 yards from the offramp. 65mph highway and cruise set to 75 daily.

My previous house had a dirt driveway and just driving on that 300 yards before getting to the 55mph highway, was worth a MASSIVE amount of fuel economy average. I'd idle down that and the car basically got 0mpg for 45 seconds to a minute, twice a day. The difference between that and simply getting on the road and go, it clearly more than you give it credit for.

I also don't recall my car running terrible at cold startup. Actually, quite the opposite. Now, I didn't take all of the enrichment out, but I decreased it quite a bit.

For the most part, fuel economy boils down to simple math. The computer keeps the car at 14.7:1 afr (or attempts to). X amount of cubic inches of displacement, times X amount of RPMs, tells you the fuel consumption. The only variables to speak of are what gear you're in (controlling final drive ratio) that's the big one,engine load (thus changing dynamic airflow) and fuel enrichment done in the tune, that's the small one. Past that, everything else is lost in the noise.

 

Also a deer crash survivor (2 actually) on my BMW motorcycles, so the Corvette is definitely a close competitor in the smiles per mile category when compared to motorcycling. My wife and I are planning a trip in the C5 to the Blue Ridge Parkway this fall.

 

The way I look at it if you worry about mpg's sell the Vette and buy a Prius.

 

I averaged 22 mpg in my A4 '03 AE coupe going to Bowling Green this week.
That was in spite of sitting in stopped traffic for over 2 hours with the air on while accidents in a construction zone clogged up I71.

I echo the sentiment; If you're sensitive about the miles per gallon and the cost of premium gas, maybe you're better served by a different car.

 

It doesn't really work like that. A/F ratio is meaningless because combustion is not 100% efficient. Furthermore, fuel pressure varies depends on the engine/vehicle, some have PWM fuel pumps and some have a reference to engine pressure, and some have none of that so it must be taken into account based on the vehicle's year as each system has it's own particular impacts on injector fuel flow.

Displacement is also a meaningless quantity when concerning fuel economy. You can get better economy with a 6L V8 than 2L 122 cubic inch 4-cylinder if the V8 is more comfortable cruising at speed and rotates slower.

Finally engines should not be used for short trips. Please see more:
https://www.corvetteforum.com/forums...post1599560628

 

Just back from a road trip of +960 miles. I reset the average gas mileage on the DIC upon hitting the highway Wednesday morning (5 miles from home, a western suburb of Chicago). I always drive at least 5 mph over the speed limit (sometimes more - 85 would have been my highest speed (and when merging, I do explore the upper range of the tach...why not?). We hit several construction zones (two seasons in the Midwest, winter and construction as the saying goes). We stopped off in Indianapolis, so there was some in town driving there, and again in Columbus where we overnighted- my gas mileage on this leg of the trip was 30.5 miles to the gallon. My wife on board and the trunk loaded with 2 suitcases.

The return trip, we stopped in Cleveland and Detroit and overnighted in Detroit. When I pulled off the highway in Detroit our average fuel economy was 30 miles to the gallon.

The return leg of the trip- we dropped the top from Detroit to Michigan City, Indiana (lunch break and some slots for the wife)- I saw the average gas mileage drop to 28.5 miles to the gallon when we pulled off the highway. I typically see a drop in mileage with the top down, so no surprise there and we had some bumper to bumper traffic to deal with as we hit the constructions zones.

Temperatures climbed into the 90s yesterday around noon, so we put the top back up. We spent over an hour in bumper to bumper traffic at the Indiana/Illinois border, such that it took us 2 1/2 hours to get home (where it should have taken us an hour and a half). Outside temperature was 95 degrees; stop/go crawl, the worst imaginable traffic. Nonetheless, our average gas mileage was 26.5 miles to the gallon.

Our car a stock, '01, manual with over 109,900 miles. As the saying goes, your mileage may vary.

 

I have a C5 and a C6 similar mileage on both. Only pic I have is from the C6