Fuel Computer Problem?
Thread Starter
Intermediate
Joined: Feb 2005
Posts: 44
Likes: 0
Fuel Computer Problem?
If you fill your tank (18 gal) and are averaging 15 mpg, the "range" display should show 15 x 18 = 270 miles. If you then jump on the highway, reset "average mpg" and now get 25 mpg, shouldn't the range be 25 x 18 = 450 miles? That's the way it worked on my C5 - it was very accurate and I relied on it a lot. The most range I show on the C6 (on the highway) with a full tank is about 317 miles. It seems to be (possibly) increasing very slowly, as if its going all the way back to the first mile driven and ignoring the reset of the average mpg. I'm only on my 2nd tank (275 miles total), but I wonder if anyone else has noticed this - or do I have a unique problem?
Racer
Joined: Nov 2004
Posts: 472
Likes: 22
i doubt the computer calculates the range by simply multiplying
the current DIC average with the remaining fuel volume. if it did, youd
get a completely insane range value if you reset your DIC average
while coasting downhill on the highway with your foot off the gas.
if you coast downhill youll see your "instant" value go as high
as 99mpg. if you reset the average value during the coast and
the computer used the new average value to calculate the range,
youd get 99mpg*18gal which is obviously bogus.
(assuming a full tank, and DIC average reset during coast)
in practice i think the computer uses a much longer average
when calculating the range that is completely unrelated to the
one displayed on the DIC which can be reset at any time.
the current DIC average with the remaining fuel volume. if it did, youd
get a completely insane range value if you reset your DIC average
while coasting downhill on the highway with your foot off the gas.
if you coast downhill youll see your "instant" value go as high
as 99mpg. if you reset the average value during the coast and
the computer used the new average value to calculate the range,
youd get 99mpg*18gal which is obviously bogus.
(assuming a full tank, and DIC average reset during coast)
in practice i think the computer uses a much longer average
when calculating the range that is completely unrelated to the
one displayed on the DIC which can be reset at any time.
Thread Starter
Intermediate
Joined: Feb 2005
Posts: 44
Likes: 0
Originally Posted by Asterism
i doubt the computer calculates the range by simply multiplying
the current DIC average with the remaining fuel volume. if it did, youd
get a completely insane range value if you reset your DIC average
while coasting downhill on the highway with your foot off the gas.
if you coast downhill youll see your "instant" value go as high
as 99mpg. if you reset the average value during the coast and
the computer used the new average value to calculate the range,
youd get 99mpg*18gal which is obviously bogus.
(assuming a full tank, and DIC average reset during coast)
in practice i think the computer uses a much longer average
when calculating the range that is completely unrelated to the
one displayed on the DIC which can be reset at any time.
the current DIC average with the remaining fuel volume. if it did, youd
get a completely insane range value if you reset your DIC average
while coasting downhill on the highway with your foot off the gas.
if you coast downhill youll see your "instant" value go as high
as 99mpg. if you reset the average value during the coast and
the computer used the new average value to calculate the range,
youd get 99mpg*18gal which is obviously bogus.
(assuming a full tank, and DIC average reset during coast)
in practice i think the computer uses a much longer average
when calculating the range that is completely unrelated to the
one displayed on the DIC which can be reset at any time.
Thanks for the thought
Advanced
Joined: Feb 2005
Posts: 83
Likes: 0
From: San Carlos CA
Since I've only had my C6 for 2 weeks, I can't comment on how it might work, but I've had cars with similar range displays for several years. Each of them seem to do some sort of weighted running average for MPG for the calculation. Thus, if you have been driving around town for the last several tanks of gas and then jump on the freeway, the range does increase, but slowly over the course of an hour or so. This seems to make sense and generally does give an accurate range for longer trips after about the first 45-60 minutes on the freeway.
It seems like a good compromise since you don't want the predicition to get too optomistic if you exit the freeway after 1/2 hour.
Ira
It seems like a good compromise since you don't want the predicition to get too optomistic if you exit the freeway after 1/2 hour.
Ira
Le Mans Master
Joined: Feb 2000
Posts: 8,593
Likes: 1
From: Yorktown Heights NY
St. Jude '03-'04-'05-'06
In 3,804 miles I have filled up 21 times. At the time of fill-up the range has been 306 to 454 miles.
The 306 mile range the DIC said 16.2 mpg. Actual mpg was 15.99
The 454 mile range the DIC said 25.6 mpg and the actual mpg was 26.26
I can email you all 21 readings if you like.
The 306 mile range the DIC said 16.2 mpg. Actual mpg was 15.99
The 454 mile range the DIC said 25.6 mpg and the actual mpg was 26.26
I can email you all 21 readings if you like.
Burning Brakes
Joined: Nov 2004
Posts: 805
Likes: 0
From: Staten Island NY
St. Jude Donor '05
Just my 2 cent's but I noticed this on my 04 Tahoe, The computer is always recalculating the fuel range. If I have 25 miles till empty and jump on the highway obviously your Avg will go up and you will get more than the 25 miles. Also if you leave your range meter on and clock the mile marker's ( which I have done ) you will notice when you hit a mile your range does not move until you move closer to the 2nd mile. I have not done this on my C6 yet but I'm sure it's the same...
Chris
Chris
Team Owner
Joined: Feb 2005
Posts: 41,331
Likes: 615
From: FL
CI-7-8-9-10 Veteran
Cruise-In IX AutoX Winner
St. Jude Donor '05 thru '11,'19,'22,'25
St. Jude/CI Name Tag Designer
Originally Posted by Another Yellow
In 3,804 miles I have filled up 21 times. At the time of fill-up the range has been 306 to 454 miles.
The 306 mile range the DIC said 16.2 mpg. Actual mpg was 15.99
The 454 mile range the DIC said 25.6 mpg and the actual mpg was 26.26
I can email you all 21 readings if you like.
The 306 mile range the DIC said 16.2 mpg. Actual mpg was 15.99
The 454 mile range the DIC said 25.6 mpg and the actual mpg was 26.26
I can email you all 21 readings if you like.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
