Use a GPS ^ posted by someone else What you want to do is drive with traffic and watch your tachometer. That is the RPM gauge, if your car has one. By marking the tach you can tell your approximate speed at any given time. You need to watch what RPM's you shift at, if you are in fifth gear cruising at 55mph then look at where your RPM's are... they will always be really close that in 5th gear at 55mph. You can then use that as an easy way to tell your speed with a broken speedometer.
It depends on the gear ratio but 1750 rpm would be good.
How fast are you going and what gear are you in???
depends on how fast you are going and what gear you are in
It is not, but the engine works harder. You generally want to keep the RPM's as low as possible while driving. If you are going to be driving for a long time at the same speed, then it's better to enable overdrive no matter how fast you are going. Not only will your engine last longer, but you get better fuel mileage!
It would be going at a speed of approx. 142.85718571 rpm.
That would depend on how fast you are driving , what the rear end gear ratio is etc.
if you want to go fast, then you change gear at redline. if you are driving normally usually 2-3k
Driving in overdrive should be done when the driver does not plan on driving fast and jamming the accelerator. Overdrive is like a last gear that helps the vehicle maintain torque at low RPM.
Driving on lower RPM's will reward you with higher gas mileage in addition to putting less wear on the engine. So, low RPM will be cheaper in the long run.
Most likely going down hill, the faster the wheels go, the higher the RPM will increase, for this to increase the vehicle either must be going downhill with no brakes applied or the throttle(acceleration) has been depressed.
Too fast or slow of rpm for gear your trying to switch into A bad or going bad shift synchronizer