Had a bit of a revelation this morning working on the E46Fanatic's Forum.
One of the members revealed that the fuel trims will change depending on the fuel you use.
For example, if you are using 10% Ethanol then your fuel trims are spot on a 4.5% lean (4.5% more fuel being injected).
Ethanol is main stream in the UK. What are you seeing in the way of total fuel trims for engines without vacuum leaks etc?
Remember that total fuel trim for a bank = short term + long term.
Here is a bit more about it. http://www.ultra-gauge.com/customer_support/knowledgebase.php?article=29
One of the members revealed that the fuel trims will change depending on the fuel you use.
For example, if you are using 10% Ethanol then your fuel trims are spot on a 4.5% lean (4.5% more fuel being injected).
14.04 stoichiometric ratio of 10% Ethanol
14.7 stoichiometric ratio of Petrol/Gas
= 0.955 of the energy density
So, The fuel trims need to inject 1-0.955 = 0.045 or 4.5% more fuel to achieve the equivalent fuel trim for Petrol, which is what is programmed into the DME.
Ethanol is not main stream where I am, so I don't have the opportunity to experiment and see if this is true.Ethanol is main stream in the UK. What are you seeing in the way of total fuel trims for engines without vacuum leaks etc?
Remember that total fuel trim for a bank = short term + long term.
Here is a bit more about it. http://www.ultra-gauge.com/customer_support/knowledgebase.php?article=29