In reply to the rising cost of petrol

[yoshi]

Superdave, being the super Dave he is, was telling me how he had worked out that the trip between Brisbane and Gold Caost will only suffer by around 5 minutes if you sit on 100km/h through the 110km/h zones. You fuel usage will drop a lot doing this.

I then came across this article and there are a few things that I would guess a lot of people already do (tune up car, run low viscosity oil, check tyre pressure.)

But here's the tips

http://howto.wired.com/wiki/Get_More_Than_...ithout_a_Hybrid

[selyaT]

Good work Yoshi, rather than complaining about it, you're using your noggin to get around it. Ppl could learn from you.

[MT]

Some of those tips are true, some are appalling

Don't idle. How many miles per gallon do you get sitting in the drive through? Zero, that's how many. If you're going to be stationary for more than 30 seconds, turn off the engine.

A car will actually use more fuel to restart than it will for idling at the average traffic light

Coast. Hyper-milers suggest turning off the engine and coasting downhill. Be warned, though - automakers and some consumer groups say you could lose the power brakes and steering, making the car hard to turn and stop.

This has to be one of the most dangerous things I have ever heard. You could lose break assist and power steering? Only could? Idiots.

Draft. This one's controversial because it's dangerous. But we trust you: Inch up behind, say, an 18-wheeler, and kill the engine as you enter its slipstream (you'll feel it). You're drafting now, getting pulled along by the truck's gas instead of your own

Ok I stand corrected, this IS the most dangerous thing I have ever heard. Get behind a massive truck going 120km/h and turn off your engine... yeah thats right... off. no acceleration, no brakes, and no steering. Awesome!!

And dont click the link to the "tips on filling up with Petrol"

No you dont need to fill your car up in the early morning, no you dont have to only squeeze til a trickle comes out, no you dont have to fill up before your tank is half empty, and no servo's arent the devil trying to rip you off for every cent you have by installing secret tubes that suck the fuel back out of your tank and into the ground when you least expect it!!

[SuperDave]

Coast. Hyper-milers suggest turning off the engine and coasting downhill. Be warned, though - automakers and some consumer groups say you could lose the power brakes and steering, making the car hard to turn and stop.

Only works if your engine isn't carburetted. You're better off with no throttle input as gravity is causing the engine to spin.

Oh yeah, and the other method to save fuel is to own a manual :P

[T.J]

some interesting points raised here but yeah quite a few really stupid ones as well who would drive behind a semi that close anyway?

thats the thing about americans one person puts out some halfbaked solution and people take it as gospel next thing you know theres hundreds of people killing themselves by switching off their engines off and loosing their power steering and brakes for the sake of saving a thimble full of petrol.

mind you ill be taking all the excess junk out maybe ease up on the throttle a bit

[wishbone]

i reckon best thing to do is....stay in nuetral going down hill and when u r at a traffic light...even if u drive an auto...its as simple as flicking the shift up...

[MR22ZZ]

i reckon best thing to do is....stay in nuetral going down hill and when u r at a traffic light...even if u drive an auto...its as simple as flicking the shift up...

actually no it's not.

There is less throttle applied when coasting downhill in gear then there is when you roll in neutral ans that is what dictates the fuel usage.

[MT]

i reckon best thing to do is....stay in nuetral going down hill and when u r at a traffic light...even if u drive an auto...its as simple as flicking the shift up...

actually no it's not.

There is less throttle applied when coasting downhill in gear then there is when you roll in neutral ans that is what dictates the fuel usage.

Dont forget the loss of engine braking, which, depending on the gradient of the hill, could save you from the guard rail.

[T.J]

well coasting in gear is better because when you back off the throttle the ecu actually cuts out the injectors for a few seconds so your saving fuel there and youve got engine braking as well

[alarum]

In regards to flicking the transmission into Neutral while declining on a hill, I've read somewhere that damage can be done to the engine due to the wheels driving the engine, and not the other way.

Has anybody heard of this?

[T.J]

In regards to flicking the transmission into Neutral while declining on a hill, I've read somewhere that damage can be done to the engine due to the wheels driving the engine, and not the other way.

Has anybody heard of this?

ive only heard of it happening to trucks on the f3 coasting in neutral or angel gear as they call it for some reason the tailshaft on one truck flew appart i dunno how true it is but its a scary thought

[Kenneth]

In regards to flicking the transmission into Neutral while declining on a hill, I've read somewhere that damage can be done to the engine due to the wheels driving the engine, and not the other way.

Has anybody heard of this?

ive only heard of it happening to trucks on the f3 coasting in neutral or angel gear as they call it for some reason the tailshaft on one truck flew appart i dunno how true it is but its a scary thought

well like everyone said, losing engine brake means it could danger ur life in few ways. one of them is using your brakes a lot more due to the increase in speed hence heating the rotors and could potentially lose ur braking ability when u need it...

[leasaunce]

there was a guy on CNN.com showing CNN about hypermiling (video still up on the website, so check it out) and he drives the honda accord 2006 i think...

he basically start up the engine then CHUCK it into D straight away (ouch! i say!)...switch the engine off then on again,etc...

but really the simple answer is just to catch the public transport? switching the engine on and off n chucking it straight to D would give more damaged to the car....

[Hiro]

In regards to flicking the transmission into Neutral while declining on a hill, I've read somewhere that damage can be done to the engine due to the wheels driving the engine, and not the other way.

Has anybody heard of this?

For a manual, if you're in neutral no damage to the engine can occur whatsoever, because there is no link between the wheels and the engine. No gears are meshing in the gearbox, and thus no drive is being transmitted either way.

As for autos, neutral is acheived completely completely differently (never been a fan of autos, and they are incredibly complex things thus hard to explain simply, but it has to do with clutch packs and the torque converter/fluid coupling) but the effect is the same - the engine is disconnected from the wheels.

Damage to the engine caused by the wheels doing the driving could only occur if the car is in gear, and the engine turned off. But then, it's just acting as an air pump, exactly the same as 99% of belt-driven piston type air compressors. If anything, the above would cause damage to the transmission, not the engine.

[SuperDave]

well like everyone said, losing engine brake means it could danger ur life in few ways. one of them is using your brakes a lot more due to the increase in speed hence heating the rotors and could potentially lose ur braking ability when u need it...

The issue is losing vacuum pressure in the braking system. The braking system has a few fail safes in it, and one of them is residual vacuum. This residual is good for one stop, two maximum if for some reason you didn't get the point the first time. Just don't pump the brake pedel, apply it once and there should be enough assitance to pull the car up. Lift your foot and you'll start to eat into the reserves and have less help the next time to apply the brakes. If you lose vacuum completely, you better hope your on roids to push the brake pedel hard enough, or go for the handbrake.

A simple display of this is to drive around with your foot in one position on the throttle (with engine on), don't change it, then pump the brake pedel untill it becomes solid. Thats how much braking power you can apply by yourself.

[Guni]

Draft. This one's controversial because it's dangerous. But we trust you: Inch up behind, say, an 18-wheeler, and kill the engine as you enter its slipstream (you'll feel it). You're drafting now, getting pulled along by the truck's gas instead of your own.

This is got to be the funniest thing I've heard. SlipStream-ing. Only do it in Need For Speed to get that extra "style" points.

lol

[SuperDave]

Draft. This one's controversial because it's dangerous. But we trust you: Inch up behind, say, an 18-wheeler, and kill the engine as you enter its slipstream (you'll feel it). You're drafting now, getting pulled along by the truck's gas instead of your own.

I'm not implying anyone is doing this, but if anyone has the slightest idea of giving it a go, just remember trucks delaminate tyres all the time. There is no way the laminating on your windscreen is stopping the tread coming through.

[da68za]

Need to rename this thread to , how to get killed saving petrol ...

[Modena]

Need to rename this thread to , how to get killed saving petrol ...

lol

In news today: "A motorist saved $1.32 in petrol by closely following a semi, he did pay with his life though when the truck suddenly applied brakes at the traffic lights..."

[Merlin]

There is less throttle applied when coasting downhill in gear then there is when you roll in neutral ans that is what dictates the fuel usage.

excuse me, but how do you figure this?

Regardless of if I'm in neutral or not, if I'm coasting down a hill my foot is off the accelerator.

So, surely, the only thing affecting the rate of fuel entering the motor at that stage is the idle setting of the carby? [or EFI equivalent]

How could putting it in neutral actually cause more fuel usage?

[Blind Kid Seeks]

There is less throttle applied when coasting downhill in gear then there is when you roll in neutral ans that is what dictates the fuel usage.

excuse me, but how do you figure this?

Regardless of if I'm in neutral or not, if I'm coasting down a hill my foot is off the accelerator.

So, surely, the only thing affecting the rate of fuel entering the motor at that stage is the idle setting of the carby? [or EFI equivalent]

How could putting it in neutral actually cause more fuel usage?

When your in neutral your car needs to use fuel to heep it idling

when your coasting in gear there is ZERO fuel going to the injectors... hence engine braking

[dannywss]

dont worry~ fuel price will drop a little as the oil per barrel has dropped recently.. for how long? who knows~

but wat i can see is that unlead is now around 1.55 per lt

[lateralus]

There is less throttle applied when coasting downhill in gear then there is when you roll in neutral ans that is what dictates the fuel usage.

excuse me, but how do you figure this?

Regardless of if I'm in neutral or not, if I'm coasting down a hill my foot is off the accelerator.

So, surely, the only thing affecting the rate of fuel entering the motor at that stage is the idle setting of the carby? [or EFI equivalent]

How could putting it in neutral actually cause more fuel usage?

When your in neutral your car needs to use fuel to heep it idling

when your coasting in gear there is ZERO fuel going to the injectors... hence engine braking

regardless of whether you drive an auto or manual, you will still use fuel when you're coasting downhill. if a gear is engaged, then the engine will be running at the ratio equivalent of the speed the wheels are turning. while you may not use as much energy and hence less fuel, there is still fuel being injected to keep the engine running.

[Blind Kid Seeks]

There is less throttle applied when coasting downhill in gear then there is when you roll in neutral ans that is what dictates the fuel usage.

excuse me, but how do you figure this?

Regardless of if I'm in neutral or not, if I'm coasting down a hill my foot is off the accelerator.

So, surely, the only thing affecting the rate of fuel entering the motor at that stage is the idle setting of the carby? [or EFI equivalent]

How could putting it in neutral actually cause more fuel usage?

When your in neutral your car needs to use fuel to heep it idling

when your coasting in gear there is ZERO fuel going to the injectors... hence engine braking

regardless of whether you drive an auto or manual, you will still use fuel when you're coasting downhill. if a gear is engaged, then the engine will be running at the ratio equivalent of the speed the wheels are turning. while you may not use as much energy and hence less fuel, there is still fuel being injected to keep the engine running.

Sorry mate that is not the case.. there is ZERO fuel being injected to the system when you are coasting in gear in a manual.

you can test this yourself... on an empty road... coast in gear and turn off your ignition, you engine wil still "run" without the ignition or the fuel.

[SuperDave]

^ This is true for EFI engines only.

Merlin/Lateralus: Carbys cannot add less fuel than idle speed, so yes down hill a carby car will be no different if in gear or in neutral.

I think this is where the confusion is coming from.