air fuel ratio

okay quick question.

03:25 With a Lambda of 0.85 we are 0.15 richer than Stoichiometric which is 15%.

with that being said the number is less than lambda 1 which would make it too lean.

03:49 If, on the other hand, I'm using the Lambda scale and I'm running at Lambda 0.85, I know at a glance that I'm 15% richer than Stoichiometric and hence removing 15% fuel will get me to Lambda 1.00.

the lambda is less than 1 so wouldn't that mean we would have to run 15% richer to get to 1?

if we removed 15% fuel like he states that would mean we get to 0.70 on the lambda scale right?

You seem a little confused - it's lean is a greater number than lambda 1.0, and rich is a lower number, not as you're thinking.

You also need to remember the change is as compared to the initial values - for example...

2/3rds of 1 is 33.3% less, but 1 is 50% more 2/3rds.

3/4rs is 75% of 1, but 1 is 133.3% of 3/4.

Great stuff from Gord. Rene if you have any other questions or are still not feeling totally clear on this please let us know.

It becomes absolutely logical if you think of lambda as something that represents air (or oxygen) in air-fuel mixture. The greater the number is the biger the oxygen content and the smaler the number is the less air is in the mixture (making it richer with fuel).