dati nang gawa yan sa mga taxis, they replace the carb jet with a smaller jet. yes it makes the mixture leaner, but it also will loss power. and you can't rev the engine above a certain rpm or else it will KNOCK. so the trade off is leaner mixture and less gas consumption for lower power and possible engine damage due to knocking at high rpm.

yung taxis ng erpats ko lahat smaller ang jets ng carb, pero if you rev it above a certain rpm, "tok-tok-tok.......", mag-knock na yung engine. can't tell at what rpm it begins to knock at wala naman rpm meter usually mga 1300cc engines. so ang gawa namin dyan nilalagyan namin ng adjusting bolt dun sa ilalim ng gas pedal (as a "nigger rigged" engine speed limitter) para di maabot yung rpm na mag-knock ang engine. otherwise, premature overhaul ka.