the important thing is the battery voltage they must both be the same
as the answer above stated, with some additions ... revving the 4 energy-producing car should be done no matter the cylinders as often the charging system is putting out very little at idle, just enough to keep the car charging/running. If you want the extra voltage boost to help the other vehicle you should rev the engine.
The only other thing to keep in mind is if both cars are negative ground. Old Chryslers (don't know if anyone still does this) were positive ground and if my mind remembers properly you can't jump a car with different grounds.
can you jump a 6 cylinder with a 4 cylinder
Yes, why not as long as the both 12 volt what's the problem.
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNOOOOOOOOOOOOOOOOOOOOOOOO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
they start around $130 for a 4 cylinder and go up from there
No, you should not attempt to jump off a big car with a V8 engine using two smaller cars with 4-cylinder engines. The weight and power difference between the vehicles can cause damage to the smaller cars and is not safe. It is best to use a properly rated jump starter or jumper cables to jumpstart a vehicle.
a 4 cylinder car is not a gas saver
If it is a twelve volt system yes. If it is a six volt system, it isn't advisable.
It depends upon cylinder in car. 3 ignition coils - 3 cylinder engine. 4 ignition coils- 4 cylinder engine.
A motorcycle can be jump started from a car. It's the same as jumping car - car except that the jumper cars engine should be off.
under the hood of the car
4 cylinder firing order is usually 1-3-4-2.
Could be 4, 6 or 8 cylinder.