someone told me if you take your car out of gear on downhills you use less petrol. If true, this may come in handy when I am skint and don't have money for petrol.
2007-01-10 22:17:29 · 15 answers · asked by redhead 3 in Cars & Transportation ➔ Other - Cars & Transportation
Don't do it it's very dangerous!
With the car in neutral there is no engine braking effect and the car is far easier to lose control of, possibly leading to an accident and greater expense than a couple of pence of fuel.
2007-01-10 22:23:34 · answer #1 · answered by Indy 1 · 1⤊ 1⤋
Depends on the age of the car. Modern cars with fuel injection use less fuel going downhill than at tick over. They do this by cutting the fuel supply to the injectors when your foot is of the pedal because you don't need power to go downhill so it just supplies air to the engine but no fuel. If you take the car out of gear, the engine then has to have fuel supplied to it to keep the engine ticking over. So the morale of the story is when going downhill, leave it in gear, take your foot of the accelerator and leave it in gear. You will use less fuel that way.
19 years as a fully qualified mechanic
2007-01-11 16:44:02 · answer #2 · answered by bikerbloke37 1 · 1⤊ 0⤋
Although you do save a small amount of fuel by "coasting" in neutral, it is extremely dangerous as you are not in full control of your motor vehicle. This is also an offence.
With modern car fuel and ignition systems, there is no need to coast because the system shuts off fuel to the engine under engine braking (i.e. going downhill with the foot off the gas).
There are more efficient ways of driving to compensate for the loss of fuel under engine braking. It was featured on Top gear a year or so ago
2007-01-11 06:43:55 · answer #3 · answered by Thomas T 1 · 1⤊ 2⤋
No. When the engine is idling in neutral it is using fuel to keep the engine going.. When the engine is being turned by the wheels it's on over-run and is using next to no fuel (just a little bit to keep the catalyst up to temperature).
Also it is better to have the extra engine braking when descending the hill.
2007-01-11 17:36:15 · answer #4 · answered by Bandit600 5 · 0⤊ 0⤋
Don't know if you use less petrol, but don't think it can be a very safe thing to do. Anyway, to make it worth while I wouldn't think you could find enough downhills slopes !!
x
2007-01-11 06:26:27 · answer #5 · answered by samantha 2 · 0⤊ 1⤋
yes and no if you have a Manuel transmission yes however re in gaging an automatic at the bottom of the hill will damage ur transmission causing u to spend more money than u saved coasting down that hill
2007-01-11 06:44:56 · answer #6 · answered by adelbert321 2 · 0⤊ 1⤋
Yes you do use less petrol as the car revs are at tick over so the engine is hardly working. p.s The question was not if its dangerous!!!
2007-01-11 06:23:53 · answer #7 · answered by ? 5 · 2⤊ 2⤋
yes but you dont have full control of the car you keep you foot on brake therefore wear brakes faster you choose
2007-01-11 06:27:56 · answer #8 · answered by Snot Me 6 · 0⤊ 2⤋
OFF COURSE ITS TRUE THE CAR IS NOT IN GEAR THEREFORE NOT USING ANY REVS (PETROL)
2007-01-11 06:26:24 · answer #9 · answered by Anonymous · 1⤊ 2⤋
It is true, do not do it with an automatic transmission, it will hurt it.
2007-01-11 06:25:30 · answer #10 · answered by Anonymous · 1⤊ 1⤋