Is it bad to turn the engine on and off frequently

[dr. d]

First observe your tachometer every time you start your car..note how high it goes (X rpm). Then observe your idle rpm (Y rpm).

Using ratio and proportion..X:Y you can deduce the number of minutes your idling engine matches the starting engines fuel consumption. 2000rpm:800rpm=2.5:1 ratio. To save fuel you need to anticipate the number of minutes you need to run idle and compare it to the ratio you get. If you will idle more than 2.5 minutes then you will save fuel by turning off your engine. If you will run idle in less than 2.5 minutes then you wont save fuel by turning off the engine because your car will gulp more fuel as you start your engine again

Every car has different oil so starting rpm is different on every car. So my ratio and proportion example could differ on each car you own. Thick oil are harder to start than thin oil so it would consume more fuel to start an engine

Now on what will be commonly affected component of your car if you frequently start an engine. Its the battery, thats why battery manufacturers cut the warranty period for commercial vehicles to just 6 months.

Sent from my GT-P3110 using Tsikot Forums mobile app

in my diesel innova, my cold starting idling rpm, is the normal temp idling rpm, is the initial few-seconds' idling rpm when started from hot.

i may have saved on gas, but i feel it made me replace my battery earlier.

i don't kill my engine anymore, during 1-2 minute red lights.