Karnataka finds up to ethanol in E petrol seeks consumer compensation. Karnataka has alleged that petrol samples from multiple oil companies contained up to 31.2% ethanol, exceeding the E20 benchmark. After testing 63 samples across the state, the government sought. Bengaluru, Nov 6 (PTI) The Karnataka government on Friday alleged that major oil marketing companies were supplying petrol with ethanol content exceeding the prescribed 20 per cent limit, with tests.