Who Needs AFM?
#1
Le Mans Master
Thread Starter
Member Since: Sep 2012
Location: Hagerstown MD
Posts: 6,876
Received 1,738 Likes
on
1,174 Posts
St. Jude Donor '15-'16,'18
Who Needs AFM?
Just returned from a 600 mile round trip from Hagerstown MD to Ocean City MD to attend the big Corvette show. I had my Range on for the entire trip. Most of the miles, about 500, were highway driving 60 - 80 mph. About 100 miles we're cruising around in Ocean City. I averaged 30.6 mpg for the entire trip without ever using V4 mode. I believe this exceeds the advertised highway MPG that I assume includes using V4 mode. So, I ask again who needs AFM? Not me.
The following 2 users liked this post by rmorin1249:
1950silverstreak (10-14-2018),
Rebel Yell (10-15-2018)
#2
It sounds like you got lost somewhere and added two hundred miles to the trip.
Where else did you go?
Where else did you go?
#3
Le Mans Master
Thread Starter
Member Since: Sep 2012
Location: Hagerstown MD
Posts: 6,876
Received 1,738 Likes
on
1,174 Posts
St. Jude Donor '15-'16,'18
Rehobeth, Assateague Island and Berlin.
#4
Safety Car
Member Since: Feb 2016
Location: Bainbridge Island WA
Posts: 4,980
Received 3,818 Likes
on
1,614 Posts
Nobody needs AFM. GM needs AFM to pass the CAFE standards. It's just like the 1-4 shift. No Corvette driver needs it. The Corporation does.
#5
Nice!
Drove my '05 on the beach on Assateague. Way back in '05.
Drove my '05 on the beach on Assateague. Way back in '05.
#6
Team Owner
Don't need it and have never used it.
#8
Le Mans Master
Member Since: Nov 2015
Location: Lake Havasu City Arizona
Posts: 7,326
Received 3,439 Likes
on
2,059 Posts
I have never noticed any real measurable difference in my mileage after disabling AFM. At most in a couple of test runs it was about a half a mile per gallon going from Lake Havasu to Las Vegas and back, but that could have been due to wind variations, etc.
#9
Le Mans Master
Having a stick, V4 is a non issue for me.
#11
Racer
Just returned from a 600 mile round trip from Hagerstown MD to Ocean City MD to attend the big Corvette show. I had my Range on for the entire trip. Most of the miles, about 500, were highway driving 60 - 80 mph. About 100 miles we're cruising around in Ocean City. I averaged 30.6 mpg for the entire trip without ever using V4 mode. I believe this exceeds the advertised highway MPG that I assume includes using V4 mode. So, I ask again who needs AFM? Not me.
Hi neighbor!
#12
Administrator
Member Since: Mar 2001
Location: In a parallel universe. Currently own 2014 Stingray Coupe.
Posts: 342,647
Received 19,204 Likes
on
13,921 Posts
C7 of the Year - Modified Finalist 2021
MO Events Coordinator
St. Jude Co-Organizer
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19-
'20-'21-'22-'23-'24
NCM Sinkhole Donor
CI 5, 8 & 11 Veteran
Sure as heck can’t complain about that MPG.
#13
Advanced
I did a recent road trip to key west. Once you hit Largo you fall in line and can only average 45 to 50 on the run to key west. I have a manual and turned on the afm just to play. In 5th gear on dead flat sea level road with the cruise control set to 50 switching the afm off would routinely drop the readout 2 or 3 mpg. I left it on for the trip through the islands and averaged 39 mpg (with a slight tailwind) from key largo to key west. I don't use afm much around town or blasting down the freeway because it is constantly shifting in and out of v4. I was however really impressed with it on the slow drive through the keys.
Last edited by BLACKCREEK; 10-15-2018 at 11:10 AM.
#15
Safety Car
Member Since: Feb 2016
Location: Bainbridge Island WA
Posts: 4,980
Received 3,818 Likes
on
1,614 Posts
Fair enough, but it's pretty good anyway. On a 1000 mile road trip I get about 29 mpg. If I used AFM I'd get about 32 mpg. The difference in cost is about $10.00. If gas mileage is a priority for you you'd get a Prius. Nothing wrong with wanting good mileage, but I doubt anyone says, "I'm getting a Corvette because it gets such good mileage."
#16
Pro
In May, averaged 29.9 MPG for a 4000 mile road trip. Used the Range the entire time. 2016, A8 Stingray.
#17
#18
E-Ray, 3LZ, ZER, LIFT
Member Since: Sep 2007
Location: NE South Carolina
Posts: 29,441
Received 9,603 Likes
on
6,616 Posts
We'll see what engine is in the C8 but my bet is it will be a turbo small CID for the same GM reason. The current Ford GT is a 3.5 Liter V6 with dual turbo's achieving 647 hp! Not bad!
In fact would love to have the F1 KERS (Kinetic Energy Recovery System.) It weighs about 60 pounds with battery and gives 160 hp for about 10 seconds. Could be used when accelerating from a stop as that is by far the worst mpg. Even in normal street driving it could be used until you reach cruising speed as you would not need 160 hp so double the time should be possible. Then like F1, the electric motor turns into generator to recover some of the braking energy to charge the system.
On average about a 1/3 of the energy that gets to the rear wheels winds up going into braking! The internal combustion engine is very inefficient. Only about 15% of the energy in gasoline gets to the rear wheels!
Last edited by JerryU; 10-15-2018 at 05:05 PM.
The following users liked this post:
joemessman (10-15-2018)
#19
Race Director
Nobody really NEEDS AFM, as these engines can still get amazing mileage even without it. However, if the technology is there, why not utilize it? I certainly like the idea of saving a few bucks on gas if I'm on a long highway trip. It's doing no harm to me, I have 8700 trouble free miles on my A8 and I let it go into V4 mode all the time. I know, nobody buys a Corvette for gas mileage, bla bla bla, I've been hearing that same thing for years. But gas is pretty damn expensive up here in Canada, it's often over $1.50 PER LITER for premium gas. So that's over $100 to fill the tank. I already spend over $500 a month on the 3 cars in our household, so any savings I can get, I will take it.
The following users liked this post:
white90conv (10-15-2018)
#20
Instructor
Perhaps I am just unlucky, but I have seen a 2 MPG drop since installing a Range. This has been in general "around town driving". I have not taken it on a road trip yet.