As said earlier, the D3 mode is ideal to use for city driving. This is because you get higher RPM at lower speeds when your step on the gas pedal at third gear. Plus, you can use the D3 if you are about to pull to a high speed since you can rev a high RPM at third gear before shifting to the next.
When should I drive with D3?
D3 is not ideal for driving on the highway because D3 is usually engaged to enable braking while driving down a steep hill. Also, D3 provides optimum speed in a stop-and-go situation, especially in a busy city. It is ideal when driving at a speed level of 30 mph or less.
What is gear D3 good for?
The best thing to do is drive on D4 normally, whether in the city or on the highway. Since you must maintain a slow speed when driving up or down a hill, you should only use D3 when driving up or down a hill.
Is it OK to drive your car in D3?
Yes, you can switch gears from D to D3 while driving an automatic transmission car. However, it would be best to slow down a bit before switching down from D to D3 if you approach a hill.