How can I identify between petrol cars and diesel cars?

Definitely easiest and fastest way to find out if you don’t see badge behind car, is to simply look at dashboard tachometer. RPM range you see will tell you difference. Car can be turned off.

Notice redline at almost 6000 RPM. So far every petrol tachometer I have seen, not even one of them have redline below 5000 rpm

 

Here on diesel car, notice redline at about 4500 RPM. 99% Diesel cars on world have redline at about 4000 RPM, never above 5000 RPM. No diesel engine in world can achieve 6000 RPM.

Other part to look out include;

.   The Badging of the car. when you see anything D, it says Diesel.

• Black smoke
• Engine pinging or knocking sounds especially when the throttle is open.
• Characteristic diesel smell, especially from the exhaust
• Smaller fuel opening when refuelling.
• Diesel engines have lower rev counter, lower rev redline.