Questions on tyre air and N gear when waiting/stopping?

coldzero SG

Two questions here.

My tyre doesnt seem to be fully pumped. Whenever I full pump it till the tyre can't be pressed in, after a while, the air in the tyre kinda gets out and I can press the tyre in again, making it seemed a bit deflated yet it's not punctured. All 4 tyres are like that. Any idea?

And also whenever you're waiting for red light to turn green or in a jam when making a stop is very frequent, do you shift to N gear or simply step on brakes while on D gear? Which will save more petrol?

TIA!

TheDream SG

Your car should have a recommended tyre pressure. If you pump it too high, air will escape more easily.

If you pump according to the recommendation and feel that a lot of air has escaped by the next day, you can use the digital pumps at petrol stations which will firstly show the pressure of your tyre (before it starts to pump any air). So you will be able to tell how much air has escaped (if at all).

The engine still runs when in Neutral. Not much point switching to N at traffic lights.

p228 SG

Your car should have a recommended tyre pressure. If you pump it too high, air will escape more easily.

The engine still runs when in Neutral. Not much point switching to N at traffic lights.

Hmm.. I don't really agree on "The engine still runs when in Neutral. Not much point switching to N at traffic lights."

Indeed the engine is still running when the gear is in neutral mode, but at least when in "N", the gear is not engaged, thus it helps in saving fuel (consumes lesser fuel than in "D" because gear is not engaged).

s0nic SG

Hmm.. I don't really agree on "The engine still runs when in Neutral. Not much point switching to N at traffic lights."

if manual, engaging to neutral might help.. no need to clutch in ma..

but if for auto, i dun see a need to change to neutral.. no point la. haha

linwei20 SG

I will suggest don't change the gear too often for auto car as the gearbox will spoil easily.. to change a gearbox or fix it is cost more than petrol.. Just my 2 cents.

Xcert SG

Hmm.. I don't really agree on "The engine still runs when in Neutral. Not much point switching to N at traffic lights."

ok....I think I see the idea...car moving....traffic light turns red...U change to N gear and let the car roll forward....brake when the stop line is near.

maybe U save that bit of petrol for rolling your car forward...but U brake harder because of free-wheeling....in short...U transfer your petrol money from petrol station to mechanic...to change ur brake pads....and I am not even talking about how dangerous it is on slippery roads/rainy days.

please do not think about changing to N gear far far away and letting it roll until the stop line so that U dont have to step so hard.if U are lucky...some guy will hit ur rear...end of story...if U unlucky...some guy will hit ur rear and U move fast fast forward...U too shocked to react...to the traffic after the stop line.Either way...get people in trouble and I dont think the benefits negates the downsides.

16/f/lonely SG

what is the logic for less fuel being consumed while gear is not engaged?

Personally I go with the engine-still-running-so-no-difference theory.

bcos of the torque converter.

TheDream SG

I think unless the engine runs at a lower speed when at N compared to D. Otherwise, there should be no difference in fuel consumption whether the gears are engaged or not (when stationary). There doesn't seem to be any difference on mine

p228 SG

ok....I think I see the idea...car moving....traffic light turns red...U change to N gear and let the car roll forward....brake when the stop line is near.

Haha.. Wrong. What i mean is changing to N when the car stop at traffic lights. Not changing to N when the car is still moving slowly.

My brake pads won't be affected when i change to "N" when stationary at the traffic light.

p228 SG

What car you driving?

For my car, got difference.. cos mine is MPV...

sinicker SG

take taxi toyota crown on expressway. taxi driver always like to press on gear 5... then switch to N... glide for about 100-150 metres, switch to gear 5.... press again.. .gear 5.. zzzz.

Xcert SG

Haha.. Wrong. What i mean is changing to N when the car stop at traffic lights. Not changing to N when the car is still moving slowly.

My brake pads won't be affected when i change to "N" when stationary at the traffic light.

I still dont think the petrol benefit is significant enough for me to want to do it, if there is such a thing in the first place.

Xcert SG

take taxi toyota crown on expressway. taxi driver always like to press on gear 5... then switch to N... glide for about 100-150 metres, switch to gear 5.... press again.. .gear 5.. zzzz.

skateboarding style.