What happens if you are going 70mph down a road in a car and suddenly turn your key off?
In my car, which is a 1997 with a manual transmission and fuel injection, turning the engine off doesn’t actually do very much. I lose the ability to indicate direction changes, since the turn signals only work when the car is on. The engine obviously will fail to produce forward power. However, if the car is in gear, the power steering and braking assist will continue to work until the car stops, since these items are driven mechanically off of the engine (either through rotation or vacuum), which is still happening because the engine is turning (if the car is moving and the car is in gear, the engine is turning).It’s actually possible to traverse long downhill segments in the mountains this way. Pressing the gas will allow the car to speed up by reducing engine vacuum, and the rotation of the engine drives the power steering as well as it would with the engine running. When you let off the gas, the vacuum is immediately restored, which allows full use of the power brakes. And you can shift gears to control speed via engine braking as normal.A lot of modern cars do basically this when you let off the gas while in gear. They will disable the fuel injectors, may disable the spark plugs, and will allow you to use the engine to brake as normal. When you the RPMs come below a set value (say, 1,500), then the ECU re-enables the fuel and spark so that the engine will idle. The means that you’re using no gas going downhill in gear (and if you put the car in neutral to “coast”, you’re actually using more gas).This won’t work in a car with carburetors. Most of these cars use mechanical devices to pump fuel and control the spark plugs, and turning the engine off will disable the ignition coil (ergo the spark plugs) but the fuel pump will keep pumping fuel and the carburetors will continue mixing air and fuel as if the car were running. Without this fuel being burned, the mixture will be pumped out the exhaust, where it will damage the catalytic converter and may flood the engine or foul the spark plugs. This is just one of the ways in which mechanical carburation is less efficient than fuel injection.
What if I shift to 1st gear while going 70 mph?
Engine will rev super high and you may even hear some harsh sounds from your transmission. I urge you to try it, FilipinoKid, it be funny to see you lose one of your famed street races that way.
What happens if I shift to 1st gear in a manual transmission vehicle while driving 130 mph?
Lots of speculation here and a couple of correct answers. I’ve never done this but I’ve had to tow the car and repair the result of a friend shifting into 1st at 100km/hr.The actual result is nowhere near as drastic as some answers here would have us believe. For the driver …. whirrr ….. bang ….. coast to a stop. That’s it.You see a clutch plate is comprised of two lining rings of reinforced friction material riveted to a spring steel plate, amongst other parts. In normal operation these rings are clamped between the flywheel and the casting of the pressure plate, and rotate at engine speed. When the clutch pedal is depressed this clamping force is released and the clutch plate is free to spin to whatever RPM the gearbox input shaft transmits to it, as a result of ratio selected and road speed.Whirrrr …. is a result of the first gear synchromesh spinning the gears and clutch plate up to, in the case of this car which could do 60 in first, around 170% of its rated RPM.Bang …. is the noise made when centrifugal force overcomes the strength of the bonded in reinforcement of the clutch plate friction linings, fractures appear near the rivets, and the linings detach and explosively meet the inner surface of the bell housing.Coast to a stop …. with nothing left on the clutch plate to afford drive, the engine can no longer propel the car, and the car’s momentum cannot overspeed the engine.130mph is double the speed I saw, but I’d speculate that the synchromesh would still be capable of spinning the clutch plate up to its designated self-destruct speed, even if it could not reach the point of full synchronisation. End result would be the same anti-climax, and a tow.
What happens if you accidently put your car into 2nd gear at 70 mph?
You can seriously mess up your car. 2nd gear is for speeds up to about 30mph. You did 40mph OVER that. You can wear out the engine and cause it to overheat, among many other problems. And yes, if your nephew rear-ended the car, it's the nephew's fault for following too close behind him.