Engine Breaking?

thefullcollapse · 21 Jul 2006 at 16:22

i was speaking to my dad about driving economically.... im currently spending £100 a month on petrol which is too much for me.

anyway, he says that aparently engine breaking forces the engine not to take petrol in, i was just wondering to what extent is this true and apart from early gear changes how else do u drive economically

-westy- · 21 Jul 2006 at 16:26

thefullcollapse said:
i was speaking to my dad about driving economically.... im currently spending £100 a month on petrol which is too much for me.

anyway, he says that aparently engine breaking forces the engine not to take petrol in, i was just wondering to what extent is this true and apart from early gear changes how else do u drive economically

get your foot off

Kazzan · 21 Jul 2006 at 16:31

thefullcollapse said:
i was speaking to my dad about driving economically.... im currently spending £100 a month on petrol which is too much for me.

anyway, he says that aparently engine breaking forces the engine not to take petrol in, i was just wondering to what extent is this true and apart from early gear changes how else do u drive economically

I believe the gas pedal is exactly that, how much fuel gets through to the engine. So when you're not touching the pedal there is no fuel being sent to the engine. EDIT: Except when ticking over... disclaimer I might be talking rubbish

To drive economically avoid pressing that pedal.

According to the manual for my car first gear is a lot more thirsty than any other gear, so if you can avoid stop-start driving by approaching red-lights far slower in the hope that you don't have to stop you should improve economy.

thefullcollapse · 21 Jul 2006 at 16:33

-westy- said:
get your foot off

...standard

Violent-J · 21 Jul 2006 at 16:34

As soon as you turn the ignition fuel is constantly delivered to the engine or else it wouldn't turn over but yeah, basically just feather the throttle, early gear changes, keep it in a high gear etc.

moss · 21 Jul 2006 at 16:35

Kazzan said:
I believe the gas pedal is exactly that, how much fuel gets through to the engine. So when you're not touching the pedal there is no fuel being sent to the engine.

does that mean my car will use no petrol at idle

thefullcollapse · 21 Jul 2006 at 16:36

so there are no other secret tricks like ....who knows

needmorespeed · 21 Jul 2006 at 16:36

£100 a month is nothing i'm doing around £240 a month :eek:

Changing gear early wont always save you petrol as you could labour the engine which will use more.

thefullcollapse · 21 Jul 2006 at 16:39

needmorespeed said:
£100 a month is nothing i'm doing around £240 a month

Changing gear early wont always save you petrol as you could labour the engine which will use more.

yes but school is only 3 miles away

Scuzi · 21 Jul 2006 at 16:41

As far as I know modern injection engines don't use any fuel when you are engine braking. So, instead of braking at the last minute, ease off the power and let the engine slow the car down.
Depending on your car, correct gear useage can also save you some fuel. People get the impression that if you do 30mph in 5th or 6th gear that you will get mega economy becuse the engine is turning over slower. Quite the opposite in fact, a higher load on the engine makes it drink the fuel.

needmorespeed · 21 Jul 2006 at 16:42

thefullcollapse said:
yes but school is only 3 miles away

get a push bike then

gord · 21 Jul 2006 at 16:45

More knowledge.. must absorb more knowledge..

Its common sense really.. dont go barging up to stuff and slam on the brakes.

I think of it as.. every time you use the brakes your wasting energy.. so dont use the brakes when you dont have to. This is not to say the brakes are off limits, but you know what i mean, keep alert for traffic stopping ahead and slow down accordingly.. if you dont have to stop then all the better.

Kazzan · 21 Jul 2006 at 16:50

thefullcollapse said:
yes but school is only 3 miles away

Another thing I picked up from reading my car's manual (yes I'm sad) was that fuel consumption is almost doubled before the engine has warmed up.

The_Dark_Side · 21 Jul 2006 at 18:55

Scuzi said:
As far as I know modern injection engines don't use any fuel when you are engine braking.

surely if it was using no fuel it would stall?

paradigm · 21 Jul 2006 at 18:58

The_Dark_Side said:
surely if it was using no fuel it would stall?

No, it uses momentum of the car to keep the engine spinning, hence I can get infinite miles to the gallon when rolling in-gear.

Acolyte · 21 Jul 2006 at 19:01

No the momentum of the car keeps the engine turning over but the "drag" of the engine means the car slow down, hence engine braking.

moss · 21 Jul 2006 at 19:05

The_Dark_Side said:
surely if it was using no fuel it would stall?

Ive read the 2 posts above, but I still thought it would stall if there was no fuel being used?
Obviously not though :confused:

L0rdMike · 21 Jul 2006 at 19:07

Did anyone else expect something about an engine actually breaking? :confused:

paradigm · 21 Jul 2006 at 19:08

How can it stall? So long as its in-gear and the clutch isn't being depressed then the wheels turning will turn the crank. The engine doesn't need fuel to keep turning.

Have you never started a car by having it rolling in gear, then just turning the ignition back to "2"? You don't need the starter at all, you just give it a bit of gas.

L0rdMike said:
Did anyone else expect something about an engine actually breaking?

No, I just assumed the OP was a n00b

Jimbeam3678 · 21 Jul 2006 at 19:09

L0rdMike said:
Did anyone else expect something about an engine actually breaking?

Nope just you