Although I especially have an old 12R-engine from Toyota but rather generally the question, what to do against high fuel consumption with old 8-valves (4-cylinders) with lower camshaft and carburetor (so all classic engines) (<17l/100km). Even if officially the oldtimer approval extinguishes (in the engine room I have never seen a TÜV tester) I would not shy away from an exchange of the carburetor for e.g. an Audi 80 injection (mono-motronic) - Electronic ignition via transistor instead of ignition coil directly at the contact. - Esoteric consumption reduction by magnets - smaller main nozzle installed in the carburettor - Further suggestions - ... - ... (Please only answers from motor specialists - Thank you !)