理論 りろん空燃 くうねん ではありませんでした
rironkūnenhidewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 理論空燃比

1. Was not the theoretical air-fuel ratio.; Was not the stoichiometric air-fuel ratio.

Past/Perfective
Negative
Polite
Formal Register