3rd Gen
When first got my 1990 b20a5 si, I was able to achieve 30mpg very consistently, even once recorded 33.
Now it has the brand new b20a5 engine, rebuilt by myself. (New o2 sensor,also.)
I cannot seem to get 30mpg again, i get 27 or 28. When i drive it less caring, even 25-26.
I started...