You can use DOT 4 in place of DOT 3 but don't use DOT 3 in place of DOT 4. DOT 4 has a higher boiling point than DOT 3. DOT 4 is in there for a reason.
No, you should only use the recommended brake fluid.
You should use DOT 4 if the manufacturer calls for it.
DOT 3 and DOT 4 brake fluids are not compatible with one another. You should only use the fluid that your car manufacturer suggests.
Use exactly what the engine manufacturer recommends.Use exactly what the engine manufacturer recommends.
You can use any kind of SAE certified transmission fluid in your 1998 Toyota Corolla. The manufacturer recommends that you never overfill the transmission fluid.
You can use any SAE certified transmission fluid in your 1987 Harley-Davidson Sportster motorcycle. The manufacturer recommends that you never overfill the transmission fluid.
The manufacturer should specify the type of fluid that should be used. If it says DOT 4, then yes it's the same DOT 4. I don't think bikes generally use DOT 4, though: it's too moisture-sensitive.
Use what ever fuel the vehicle manufacturer recommends.
No. Use what the car manufacturer calls for.
You must use the oil that the manufacturer recommends in the handbook.
No! Use DOT 3 or DOT 4 brake fluid.
The owners manual recommends to use Mopar Dot3 but any decent Dot 3 is good to use. But if anyone is looking for a recommendation of a decent brand instead of the Mopar one (since it's a bit pricey at the dealers). Try the Prestone DOT 3 synthetic brake fluid.
Yes, you can use either DOT 3 or DOT 4 and they can be mixed. You cannot use DOT 5.