What car/driving related urban myths have you heard of?

[CommanderJameson]

Twincam16 said:

'The faster you go, the more fuel you use' - typically said by the sort of people who can be found doing 50 in the middle lane. To them (and the government, it seems), fuel use is related only to speed. So nothing to do with gearing, torque, aerodynamics, weight distribution and reduction, rate of acceleration - etc...

All else being equal, the fact that drag squares with speed means that yes, the faster you go the more fuel you use.

Dunno why you'd even try to argue about that one, tbh.

[denniswise9]

Opulent said:

You mean, as you approach them, and if there is nothing on the other side of the road, then they change?

That will be detector/control loops cut in to the road.

Traffic lights do not respond to light signals.

There really is no argument to it.

There is.

I'll film it tonight.

[CommanderJameson]

denniswise9 said:

There is.

I'll film it tonight.

>popcorn<

[5lab]

doogz said:

CommanderJameson said:

Twincam16 said:

'The faster you go, the more fuel you use' - typically said by the sort of people who can be found doing 50 in the middle lane. To them (and the government, it seems), fuel use is related only to speed. So nothing to do with gearing, torque, aerodynamics, weight distribution and reduction, rate of acceleration - etc...

All else being equal, the fact that drag squares with speed means that yes, the faster you go the more fuel you use.

Dunno why you'd even try to argue about that one, tbh.

Please see my previous post, and explain why you don't drive everywhere at 5mph. Also, what's a gearbox for?

I'm not sure how weight *distribution* affects fuel economy though? unless it means you can go quicker round corners so less energy is lost by braking? bit tenuous

[Gad-Westy]

DodgeRam Van Man said:

tvrgit said:

I'll say it again. No traffic lights have a sensor to detect flashing headlights. It's a myth. The subject of this thread. Myth.

You keep saying it, but you are wrong as I've done it myself so know it's a fact, no question! I've done successfully it a grand total of twice over the years, both at temporary lights. The first time I did it was many years ago, waiting at the lights gave it a couple of flashes and the light went from red to green immediately, skipping the red/amber phase.
The second time was only a year or so ago, the lights were up ahead of me and had just gone from green to red, and a car was waiting to pull out of a driveway between me and the lights. I flashed the car to come out, and straight away the traffic lights jumped from red to green - they had only been on red for a few seconds!

I have to say that with a scientific study as comprehensive as this, it is very hard to dispute the existence of light sensors! Once could have just been coincidence but TWICE in several years! Well that's proof right there.




















Although thinking about it, maybe the lights would have changed anyway....

[LuS1fer]

Look, can you all please just STOP with the light sensors!


Now flash your lights and we can all continue with the thread...

[Zippee]

Rickyy said:

Polishing your care makes it more aerodynamic, thus saving fuel!

Knew a guy years ago that was adamant that pumping the clutch (cadence clutching as its known here) was more effective than changing down a gear!

http://www.pistonheads.com/gassing/topic.asp?t=160496

[Gad-Westy]

doogz said:

CommanderJameson said:

Twincam16 said:

'The faster you go, the more fuel you use' - typically said by the sort of people who can be found doing 50 in the middle lane. To them (and the government, it seems), fuel use is related only to speed. So nothing to do with gearing, torque, aerodynamics, weight distribution and reduction, rate of acceleration - etc...

All else being equal, the fact that drag squares with speed means that yes, the faster you go the more fuel you use.

Dunno why you'd even try to argue about that one, tbh.

Please see my previous post, and explain why you don't drive everywhere at 5mph. Also, what's a gearbox for?

He did say 'all else being equal'. The statement isn't wrong it's just that all things aren't equal and driving at 5 mph isn't very efficient. You could design a car that was extremely efficient at 5 mph but realistically only my gran would buy it.

Edited by Gad-Westy on Friday 4th November 11:25

[Corpulent Tosser]

98elise said:

martin84 said:

robsco said:

That if you run your fuel level too low, you start to suck up all the dregs at the bottom of the tank which is bad for your engine. Who made that st up?

People always buy this one but nobody ever asks where the dregs came from or how they got there. Baffling.

Or why they don't get churned up by filling the tank, or sloshing about when the car is being driven

Older cars may have rust in the tank which would provide the contaminant, water from condensation, or even just crap in the fuel when you buy it.
The more fuel you have in the tank the lower the percentage of contaminants, low fuel level,more crap being sucked into the fuel line.
Why do you think your vehicle has a filter in the fuel line ?

[LuS1fer]

Listening to Neil Sedaka in the car makes you drive like a lunatic.

[Gad-Westy]

LuS1fer said:

Listening to Neil Sedaka in the car makes you drive like a lunatic.

FACT! One of many reasons why all of Sedaka's back catalogue should be banned.

[EDLT]

Corpulent Tosser said:

98elise said:

martin84 said:

robsco said:

That if you run your fuel level too low, you start to suck up all the dregs at the bottom of the tank which is bad for your engine. Who made that st up?

People always buy this one but nobody ever asks where the dregs came from or how they got there. Baffling.

Or why they don't get churned up by filling the tank, or sloshing about when the car is being driven

Older cars may have rust in the tank which would provide the contaminant, water from condensation, or even just crap in the fuel when you buy it.
The more fuel you have in the tank the lower the percentage of contaminants, low fuel level,more crap being sucked into the fuel line.
Why do you think your vehicle has a filter in the fuel line ?

Out of interest, where do you think the fuel pump draws fuel from?

[mattnunn]

Myth - honda have never had a warranty claim on an engine

Truth - they have, my 2006 civic, several new engine parts aswell as several other things.

[Twincam16]

5lab said:

doogz said:

CommanderJameson said:

Twincam16 said:

'The faster you go, the more fuel you use' - typically said by the sort of people who can be found doing 50 in the middle lane. To them (and the government, it seems), fuel use is related only to speed. So nothing to do with gearing, torque, aerodynamics, weight distribution and reduction, rate of acceleration - etc...

All else being equal, the fact that drag squares with speed means that yes, the faster you go the more fuel you use.

Dunno why you'd even try to argue about that one, tbh.

Please see my previous post, and explain why you don't drive everywhere at 5mph. Also, what's a gearbox for?

I'm not sure how weight *distribution* affects fuel economy though? unless it means you can go quicker round corners so less energy is lost by braking? bit tenuous

Sorry - was in a rush when I typed that - what I was referring to was carrying heavy loads in the car. The rest still stands though.

[Gad-Westy]

doogz said:

Gad-Westy said:

doogz said:

CommanderJameson said:

Twincam16 said:

'The faster you go, the more fuel you use' - typically said by the sort of people who can be found doing 50 in the middle lane. To them (and the government, it seems), fuel use is related only to speed. So nothing to do with gearing, torque, aerodynamics, weight distribution and reduction, rate of acceleration - etc...

All else being equal, the fact that drag squares with speed means that yes, the faster you go the more fuel you use.

Dunno why you'd even try to argue about that one, tbh.

Please see my previous post, and explain why you don't drive everywhere at 5mph. Also, what's a gearbox for?

He did say 'all else being equal'. The statement isn't wrong it's just that all things aren't equal and driving at 5 mph isn't very efficient though you could design a car that was extremely efficient at 5 mph but realistically only my gran would buy it.

It's still not true. The lorry i learned in, had a coloured in rev counter. The engine used less fuel at 2500rpm, than 2000rpm. Most things are the same. Low revs doesn't automatically mean low fuel consumption.

It's still true. Nobody mentioned low revs. Any engine (or motor for that matter) has a speed with a peak efficiency. If you run the engine constantly at that speed but through a gearbox which makes the road speed lower, you will use less fuel. Hence the 'all else being equal' part.

[Gad-Westy]

doogz said:

Gad-Westy said:

It's still true. Nobody mentioned low revs. Any engine (or motor for that matter) has a speed with a peak efficiency. If you run the engine constantly at that speed but through a gearbox which makes the road speed lower, you will use less fuel. Hence the 'all else being equal' part.

Fair enough. In that improbable situation, that statement will hold true. Do you think that's what the person that said it meant? Or are we all just being overly-pedantic for fun?

Edited by doogz on Friday 4th November 11:44

Pedantic? Moi? This conversation stemmed from:

doogz said:

Please see my previous post, and explain why you don't drive everywhere at 5mph. Also, what's a gearbox for?

I was only answering your own question.

[Alfanatic]

doogz said:

It's still not true. The lorry i learned in, had a coloured in rev counter. The engine used less fuel at 2500rpm, than 2000rpm. Most things are the same. Low revs doesn't automatically mean low fuel consumption.

Do you mean that you had to use less pressure on the accelerator to cruise at a faster road speed at 2500rpm than at a slower road speed at 2000rpm in the same gear, or that you used the same or more throttle but that the truck used less fuel at the higher revs and speed, or do you mean that the lorry was more efficient at a fixed speed in, say 3rd gear at 2500rpm than it was in 4th at 2000rpm?

If it's the latter, then the point still holds true even if, while there may be more and less efficient ways to make a vehicle travel at 50mph, you will always need more fuel to make it do 60mph unless you're using very inefficient parameters at 50 and change to very efficient parameters at 60.

[GC8]

tvrgit said:

OK let's start from here:

How many sets of traffic signals have you personally designed and specified? I'll go first - about 200.

How long is it since you designed your first set? I'll go first again - 31 years.

Where does it say in the T2500 specification, or on the forms for setting up the controller, that there is a headlamp sensor? I've never seen it.

Your turn.

Seriously mate, it's a popular myth, but there is NO headlamp sensor in UK traffic signals.

Radar is it not, as proved by many a detector? Traffic lights and supermarket doors always used to send them into a frenzy.

[MDT]

That the MK3 golf 8v has more torque than the 16v one

[mattnunn]

MDT said:

That the MK3 golf 8v has more torque than the 16v one

is that really not true? Perhaps the 8v made peak torque lower down the revs?