Tulsa Vette Guy
03-18-2011, 1:04pm
********************FUEL*********************
REGULAR, PREMIUM, REAL GAS
10% ETHENOL, 15% ETHENOL
WHATS RIGHT FOR YOU!!!!!
It’s so confusing these days. After reading the headline in the local news paper a few weeks back I felt it was time to share with you what I know about fuel and our Corvettes. First off let me start by saying I don’t know it all. I do know how the computer in your car works and what’s programmed into it. The performance side my business requires that I reprogram certain parts of the computer for the modifications you have made to your cars, eg; Headers, cold air intake systems, aftermarket cams, and cylinder heads.
Let’s start off with your situation. Is your car stock?
1985 through 1995 Vettes. Your injectors will probably go out if you are using 10% or more Ethenol.
It’s just a matter of time. Take the opportunity to upgrade to the new style injectors when your time comes. Your car will run better and mileage will pick up a bit. Newer Vettes have a different injector so the E10 and E15 Fuels won’t hurry them.
Most of us know fuel burns at 14.7 to 1 parts air to fuel. Actually premium fuel burns at 14.63 to 1. Anyway what’s important to know is 10% Ethenol burns at 14.13 to and the new 15% Enthenol will burn at approximately 13.85 to 1. So, every time you dilute real gas with Ethenol you will have to use more fuel to make the same amount of power. If you get nothing else from this article get this…..every time you floor the gas pedal on your Vette you will need more fuel with Ethenol blends.
The computer in your car is programmed to go richer than normal Air to Fuel Ratio at wide open throttle positions. Most vettes are in the 11.3 to 11.8 Air to Fuel Ratio range. Now with E10 that changes to 11.8 to 12.3 which is still a good safe ratio. But go to E15 and that ratio changes to 12.1 to 12.6 and you don’t have much of a safety margin left. One bad tank of fuel and you could damage your engine.
YOUR CAR IS MODIFIED?
This opens so many scenarios that I can’t cover them all in this article. Here is Readers Digest version. Your car has been modified. You had it tuned (Computer was Reprogrammed for your modifications) by someone that assumed you ran real gas all the time. Most tuners will set your wide open throttle air to fuel ratio 12.8 to 1 for max power. After all isn’t that why you modded your car. Now if you are running E10 your air to fuel ratio is really 13.3 to 1 and you are living on a prayer. You don’t have a chance on E15. LS motors are famous for loosing cylinder number seven in the above scenario. There has been 2 club members loose motors that has been inspected both engines the damage was due to “detonation”. When this happens the piston and the engine block cracks. You now have a boat anchor.Bottom line is this, if your car is modified and tuned have someone look at your tune and by all means let him know what fuel you are running.This article was written by a well know tuner, I have taken this article to post in hopes it will help other Vette owners as well as myself. Thanks to the writer for his study of fuels and tunes.
REGULAR, PREMIUM, REAL GAS
10% ETHENOL, 15% ETHENOL
WHATS RIGHT FOR YOU!!!!!
It’s so confusing these days. After reading the headline in the local news paper a few weeks back I felt it was time to share with you what I know about fuel and our Corvettes. First off let me start by saying I don’t know it all. I do know how the computer in your car works and what’s programmed into it. The performance side my business requires that I reprogram certain parts of the computer for the modifications you have made to your cars, eg; Headers, cold air intake systems, aftermarket cams, and cylinder heads.
Let’s start off with your situation. Is your car stock?
1985 through 1995 Vettes. Your injectors will probably go out if you are using 10% or more Ethenol.
It’s just a matter of time. Take the opportunity to upgrade to the new style injectors when your time comes. Your car will run better and mileage will pick up a bit. Newer Vettes have a different injector so the E10 and E15 Fuels won’t hurry them.
Most of us know fuel burns at 14.7 to 1 parts air to fuel. Actually premium fuel burns at 14.63 to 1. Anyway what’s important to know is 10% Ethenol burns at 14.13 to and the new 15% Enthenol will burn at approximately 13.85 to 1. So, every time you dilute real gas with Ethenol you will have to use more fuel to make the same amount of power. If you get nothing else from this article get this…..every time you floor the gas pedal on your Vette you will need more fuel with Ethenol blends.
The computer in your car is programmed to go richer than normal Air to Fuel Ratio at wide open throttle positions. Most vettes are in the 11.3 to 11.8 Air to Fuel Ratio range. Now with E10 that changes to 11.8 to 12.3 which is still a good safe ratio. But go to E15 and that ratio changes to 12.1 to 12.6 and you don’t have much of a safety margin left. One bad tank of fuel and you could damage your engine.
YOUR CAR IS MODIFIED?
This opens so many scenarios that I can’t cover them all in this article. Here is Readers Digest version. Your car has been modified. You had it tuned (Computer was Reprogrammed for your modifications) by someone that assumed you ran real gas all the time. Most tuners will set your wide open throttle air to fuel ratio 12.8 to 1 for max power. After all isn’t that why you modded your car. Now if you are running E10 your air to fuel ratio is really 13.3 to 1 and you are living on a prayer. You don’t have a chance on E15. LS motors are famous for loosing cylinder number seven in the above scenario. There has been 2 club members loose motors that has been inspected both engines the damage was due to “detonation”. When this happens the piston and the engine block cracks. You now have a boat anchor.Bottom line is this, if your car is modified and tuned have someone look at your tune and by all means let him know what fuel you are running.This article was written by a well know tuner, I have taken this article to post in hopes it will help other Vette owners as well as myself. Thanks to the writer for his study of fuels and tunes.