[Brentco]

Originally Posted by ta6point6

I try to hit 14.1 for emissions and fuel economy. It is interesting to watch the numbers but they do change with outside tempature, time of day and highway driving. This chart kind of shows it all

That’s a good graph. But the line showing best fuel economy at 16 is a bit misleading, IMO. That might work in some instances with modern computer controlled fuel injection cars. But with carbed cars, going any leaner than stoich (14.7) generally gives you no better, or even worse, fuel economy, as Formulajones said. You wouldn’t want to go for 16 anyway, because that’s right on the knife edge and normal fluctuations could bring you up into engine damaging lean territory unless you manage your tune like a hawk.