A fuel analysis system is described configured to assist vehicle drivers/users in preventing damage to their vehicles caused by bad fuel. Bad fuel can leave a driver and passengers stranded on the road in need of emergency road side service, and in many instances, results in permanent damage to the vehicle. The disclosed fuel analysis system describes an enhanced bad fuel sensor system that measures a delta in vehicle operation data to identify and in many instances, pre-emptively alert, a user of a vehicle of bad fuel. The fuel analysis system may use crowdsourcing through aggregation of refueling event profile records from a plurality of vehicles' telematics devices to increase the accuracy with which bad fuel is detected.