Dreamwaker:
Dear Op, what primary and secondary school did you go to? I want to make sure that my kids DO NOT attend that school.

This is obviously too big for you to comprehend

ableguy:


This is obviously too big for you to comprehend

You will obviously say a kilo of stones is heavier than a kilo of feathers.

ableguy:

we are talking about two cars reading in the same odometer be it in km/h or mile per hour. Let me rephrase it, can a V8 traveling at the speed of 120km/h overtake a 4 cylinder car doing the same speed? Because normally people will tell you the 4 cylinder car won't even come close because of the capacity.

That is why I have the 120 in quotes when people argue.

The only condition for cars at same speed moving faster than another is misrepresentation of unit of speed and wheel size

The answer is capital NO. There is no way a vehicle can overtake or run faster than another at same speed. It is like asking if a 120kg iron is heavier than 120kg cotton wool

erico2k2:

i think you are getting it a bit mixed up
In Physics SPEED is the rate at which something move.So teh speed in question is the rate at which the car moves in this case 120m/Km per hour
in simple terms if the distance frm A to B is 120km then it takes the object or car an hour to get from A to B as far is its speed is constant.So if you was driving a F1 car with 30inch tyres and I was flying Edo Air and are both doing 120km/her, we would both get there in one hour as far as we are both doing same constant speed.

I think I get sultaan's point. Although, he left calibration out.

The bigger the tire or rim diameter the higher the speed. That's where I agree with him.

However, vehicle transmistions are calibrated to be used with specific diameter of tires/rims for the speedometer to be accurate. Any change from factory sized tires and rims render the speedometer incorrect. In this case, the car with a larger sized tire than spec will be faster even though the car speedometer reads 120km/h. This is just an apparent speed not the real speed.

Driver A can claim he overtook driver B st the same apparent speed but their real speed isn't same. With real speed there is no way there will be an overtaking just like you explained

adanny01:


I think I get sultaan's point. Although, he left calibration out.

The bigger the tire or rim diameter the higher the speed. That's where I agree with him.

However, vehicle transmistions are calibrated to be used with specific diameter of tires/rims for the speedometer to be accurate. Any change from factory sized tires and rims render the speedometer incorrect. In this case, the car with a larger sized tire than spec will be faster even though the car speedometer reads 120km/h. This is just an apparent speed not the real speed.

Driver A can claim he overtook driver B st the same apparent speed but their real speed isn't same. With real speed there is no way there will be an overtaking just like you explained

Nop
to your first line about sizes of tyres there is a simple way to explain it to you
If you did physics lets go back to gears and gear ratios or simple cogs.
A small gear turning another small gear will have a higher speed output that same gear turning a bigger
next line i would like you to research is this, why do you think the speed sensor in your car is either out the transfer case or in the mid axle and not on your tyres/hub?
I give you a quick reference, the jeep l iberty and its likes have thier speed sensor pointing directly to the rear axle assy,this is where the speedometer picks its speed from.
This might help
http://www.explainthatstuff.com/how-speedometer-works.html

erico2k2:

Nop
to your first line about sizes of tyres there is a simple way to explain it to you
If you did physics lets go back to gears and gear ratios or simple cogs.
A small gear turning another small gear will have a higher speed output that same gear turning a bigger
next line i would like you to research is this, why do you think the speed sensor in your car is either out the transfer case or in the mid axle and not on your tyres/hub?
I give you a quick reference, the jeep l iberty and its likes have thier speed sensor pointing directly to the rear axle assy,this is where the speedometer picks its speed from.
This might help
http://www.explainthatstuff.com/how-speedometer-works.html

Quoting from the link you gave

What we really need is a way of figuring out how fast the car's wheels are turning. If we know how big the wheels are, we can then figure out the speed fairly easily.

The way a car speedometer tells the speed is a direct relationship between how fast the transmission is rotating to the diameter of the tires which actually tells the distance travelled. Speed is a relation of distance covered with time. The tires give distance cover and the rotation of the shaft gives the time.

A speed sensor of a car cannot tell the distance covered by the tires but is calibrated to a specific distance (size of tire). Change the size of tire and calibration is off.

Secondly, you have mistaken one thing. A small input gear turning a small output gear will give higher torque but not speed. That's why a bicycle has a very small output gear and a big input gear and bigger tire. Understand, how bicycle gears work and you would understand the whole concept. Bicycle with 9 gears have 3 at the front and 6 at the back. The highest torque is achieved with the smallest gear at the input and the biggest gear a the output while the highest speed is achieved with a combination of biggest input and smallest output gears.

In addition, the bigger the output tire, the more the distance covered at the same rate of rotation the higher the speed.

The smaller the output gear the higher the speed and the less the torque. The bigger the input gear the bigger the speed too. In out thread of discussion, the gear system doesn't change but a tire size change affects speedometer accuracy.

adanny01:


Quoting from the link you gave

The way a car speedometer tells the speed is a direct relationship between how fast the transmission is rotating to the diameter of the tires which actually tells the distance travelled. Speed is a relation of distance covered with time. The tires give distance cover and the rotation of the shaft gives the time.

A speed sensor of a car cannot tell the distance covered by the tires but is calibrated to a specific distance (size of tire). Change the size of tire and calibration is off.

Secondly, you have mistaken one thing. A small input gear turning a small output gear will give higher torque but not speed. That's why a bicycle has a very small output gear and a big output gear and bigger tire. Understand, how bicycle gears work and you would understand the whole concept. Bicycle with 9 gears have 3 at the front and 6 at the back. The highest torque is achieved with the smallest gear at the input and the biggest gear a the output while the highest speed is achieved with a combination of biggest input and smallest output gears.

In addition, the bigger the output tire, the more the distance covered at the same rate of rotation the higher the speed.

The smaller the output gear the higher the speed and the less the torque. The bigger the input gear the bigger the speed too. In out thread of discussion, the gear system doesn't change but a tire size change affects speedometer accuracy.

I know exactly waht Im saying, you are bringing toque into the mix which os of no significant, cos we talking how fast a vehicle goes which has nothing to do with toque whis is power.let us stick with speed for now.
You see the Pic below, that gear I circled in red, is what the speed sensor bears down to, it counts how many times the gears goes past it.However big your tyre is the size of that gear remains same and thats what the speed sensor counts(putting it that way).Do not forget the speed sensor is just a magnet that gets interpreted by the car's computer.
So from here you can see the sensor picks the speed(motion)here before it gets to the tyres irrespective of your tyre size, this is same as well for those that have it in the rear assy.Its this spider gear that turns the shaft that turns your tyres.
Another typical way to explain this is simple,from waht you are saying if you upgrade your BMW tyres from 15 to 17 like I did then you will be getting speeding tickets right cos bro your odometer is a big thing in the west to check your speed limit.

This is getting interesting
I have a tendency of not fully explaining things hoping people will put things together. For those into wheeling they know to calibrate their speedometer.

The engine turns at X rpm which turns the trans at y rpm based on the gear and the trans turns the wheels at Z rpm if 2 similar cars are running at 2000 rpm in the same gear but one cars tire has a circumference 10% bigger than the other do you think it will travel 10% faster or at same speed

sultaan:
This is getting interesting
I have a tendency of not fully explaining things hoping people will put things together. For those into wheeling they know to calibrate their speedometer.

The engine turns at X rpm which turns the trans at y rpm based on the gear and the trans turns the wheels at Z rpm if 2 similar cars are running at 2000 rpm in the same gear but one cars tire has a circumference 10% bigger than the other do you think it will travel 10% faster or at same speed

You are correct in that sense . But bro come to think of it this means each time you change your tyres you prescribed speed changes
question do you think this would be normal?
This was a problem faced by early Engineers bro
to get rid of this the readings of your speed had to be picked from something me and you can change its size
hence the pic above .

Nobody is even talking about

aerodynamics, age and size of the vehicles.

Would you say a bus or truck travelling at 120km will have the same speed as a Toyota Avalon at same 120km?

Or say a 2000 Avalon at 120km will have same speed with a 2015 Avalon also at 120km....

If the speed is the same, then why do people change cars?

oweniwe:
Nobody is even talking about

aerodynamics, age and size of the vehicles.

Would you say a bus or truck travelling at 120km will have the same speed as a Toyota Avalon at same 120km?

Or say a 2000 Avalon at 120km will have same speed with a 2015 Avalon also at 120km....

If the speed is the same, then why do people change cars?

yes Boss
check this would you say 120kg of steel weigh same as 120kg of cotton ? There lays ur answer.

erico2k2:

I know exactly waht Im saying, you are bringing toque into the mix which os of no significant, cos we talking how fast a vehicle goes which has nothing to do with toque whis is power.let us stick with speed for now.
You see the Pic below, that gear I circled in red, is what the speed sensor bears down to, it counts how many times the gears goes past it.However big your tyre is the size of that gear remains same and thats what the speed sensor counts(putting it that way). Do not forget the speed sensor is just a magnet that gets interpreted by the car's computer.
So from here you can see the sensor picks the speed(motion)here before it gets to the tyres irrespective of your tyre size, this is same as well for those that have it in the rear assy.Its this spider gear that turns the shaft that turns your tyres.
Another typical way to explain this is simple,from waht you are saying if you upgrade your BMW tyres from 15 to 17 like I did then you will be getting speeding tickets right cos bro your odometer is a big thing in the west to check your speed limit.

The bolded part is my main contention.

Dont forget you brought the issue of gear ratio which has 2 outputs, speed and torque.

It seem you missed my point. I am not saying or talking about how the speedometer works but the fact that the speedometer is a calibrated equipment which one of the factors is diameter if tire. The pic and your explanation gives a working description of that equipment without taking into account factors that gives it accuracy.

See from this www.wikipedia.org/wiki/Speedometer

The return spring is calibrated such that a given revolution speed of the cable corresponds to a specific speed indication on the speedometer. This calibration must take into account several factors, including ratios of the tailshaft gears that drive the flexible cable, the final drive ratio in the differential, and the diameter of the driven tires.

erico2k2:

I know exactly waht Im saying, you are bringing toque into the mix which os of no significant, cos we talking how fast a vehicle goes which has nothing to do with toque whis is power.let us stick with speed for now.
You see the Pic below, that gear I circled in red, is what the speed sensor bears down to, it counts how many times the gears goes past it.However big your tyre is the size of that gear remains same and thats what the speed sensor counts(putting it that way).Do not forget the speed sensor is just a magnet that gets interpreted by the car's computer.
So from here you can see the sensor picks the speed(motion)here before it gets to the tyres irrespective of your tyre size, this is same as well for those that have it in the rear assy.Its this spider gear that turns the shaft that turns your tyres.
Another typical way to explain this is simple,from waht you are saying if you upgrade your BMW tyres from 15 to 17 like I did then you will be getting speeding tickets right cos bro your odometer is a big thing in the west to check your speed limit.

I did some exercise on paper, pls don't mind the handwriting.

I believe this should drive home my point. And yes, you can get a speeding ticket without your knowledge of being over the limit if you did increase the diameter of your tires. It can also be said that your speedometer becomes incorrect when you don't use manufacturer recommended tire size.

here's my my contribution to this
according to the mod, he made mention of the word 'Possible' which i can answer by saying for now nothing is impossible.
On the topic, for all cars Speed remains the same but the time at which you attain that speed is what varies which is determined by the power of the engine.
so here we have speed = Distance/time km/h
Power = Force * Speed which is gotten from the engine capacity determined by the number of Plug of the engine.
On the issue of possibility of the above, here are the likelihood:
Bad/week calibration of the instrument cluster due to old age or tampering of the odometer thereby giving the wrong measure of the speed at a giving time. a closer look at the attached picture should shed more light. please Note that the care is at Rest.
the above case is common to the fuel gauge.

auto.howstuffworks.com/car-driving-safety/safety-regulatory-devices/speedometer4.htm

erico2k2, i just found the link above which did exactly what I did.

Beetee1:
here's my my contribution to this
according to the mod, he made mention of the word 'Possible' which i can answer by saying for now nothing is impossible.
On the topic, for all cars Speed remains the same but the time at which you attain that speed is what varies which is determined by the power of the engine.
so here we have speed = Distance/time km/h
Power = Force * Speed which is gotten from the engine capacity determined by the number of Plug of the engine.
On the issue of possibility of the above, here are the likelihood:
Bad/week calibration of the instrument cluster due to old age or tampering of the odometer thereby giving the wrong measure of the speed at a giving time. a closer look at the attached picture should shed more light. please Note that the care is at Rest.
the above case is common to the fuel gauge.

Yes, its all about calibration. The easiest way to tamper with a speedometer is by changing tire diameter. Others include bad calibration, bad speedometer components or even placing a magnet close to the mechanism will affect it and so on.

My friends car recommended tire is 225/50R17 but he was adviced to use 225/55R17 for better ground clearance. Driving the car at 120km/h seem like 140km/h and 140km/h seem like 160km/h. That was when it down on me that the increase in tire size had actually been deceiving us. He has lost 3 tires to pot holes thinking his speedi is ordinary 140km/h but is actually much more which explains why he has been losing tires. Intact, he lost a very sound engine when he tried to overtake another car while he was already at 160km/h. I knew because of his tires he was probably in the range of 180-190 without knowing and pressing the engine further. He told me that seconds after down shifting the engine gave a explosive sound. His conrod broke and annihilated the engine block. Probably the engine speed limiter wasnt working and he revved into the red zone. This happened on Kaduna-Zaria express way.

^^ Na wa o

adanny01:


The bolded part is my main contention.

Dont forget you brought the issue of gear ratio which has 2 outputs, speed and torque.

It seem you missed my point. I am not saying or talking about how the speedometer works but the fact that the speedometer is a calibrated equipment which one of the factors is diameter if tire. The pic and your explanation gives a working description of that equipment without taking into account factors that gives it accuracy.

See from this www.wikipedia.org/wiki/Speedometer

what you said is true of Old cars old school,newer cars now use a speed sensor no cable or stuff.check this
Electronic speedometers work in a completely different way. Small magnets attached to the car's rotating drive shaft sweep past tiny magnetic sensors (either reed switches or Hall-effect sensors) positioned nearby. Each time the magnets pass the sensors, they generate a brief pulse of electric current. An electronic circuit counts how quickly the pulses arrive and converts this into a speed, displayed electronically on an LCD display. Since the circuit is measuring the number of wheel rotations, it can also keep a count of how far you've traveled, doubling-up as an odometer (distance-measuring meter). Electronic speedometers can also display speeds with analog pointers and dials, just like traditional eddy-current speedos: in that case, the electronic circuit drives a highly controllable electric motor (called a stepper motor) that rotates the pointer through an appropriate angle. Electronic speedometers are more reliable and compact than mechanical ones and the motion sensors can be any distance from the display that shows you your speed, making them suitable for any kind of vehicle ...
Im sure you must have heard of a Speed sensor,the speed is read by an ECU hence it can only be harked fru your OBD11 port.
That gear I showed in the picture is the Only calibration needed and its constant, I stand to be corrected, its either in teh axle or the output of your gear Box.
if we agree on the above now explain to me how the size of the tyre would influence the speed reading the sensor takes reading before the tyre?

erico2k2:

what you said is true of Old cars old school,newer cars now use a speed sensor no cable or stuff.check this
Electronic speedometers work in a completely different way. Small magnets attached to the car's rotating drive shaft sweep past tiny magnetic sensors (either reed switches or Hall-effect sensors) positioned nearby. Each time the magnets pass the sensors, they generate a brief pulse of electric current. An electronic circuit counts how quickly the pulses arrive and converts this into a speed, displayed electronically on an LCD display. Since the circuit is measuring the number of wheel rotations, it can also keep a count of how far you've traveled, doubling-up as an odometer (distance-measuring meter). Electronic speedometers can also display speeds with analog pointers and dials, just like traditional eddy-current speedos: in that case, the electronic circuit drives a highly controllable electric motor (called a stepper motor) that rotates the pointer through an appropriate angle. Electronic speedometers are more reliable and compact than mechanical ones and the motion sensors can be any distance from the display that shows you your speed, making them suitable for any kind of vehicle ...
Im sure you must have heard of a Speed sensor,the speed is read by an ECU hence it can only be harked fru your OBD11 port.
That gear I showed in the picture is the Only calibration needed and its constant, I stand to be corrected, its either in teh axle or the output of your gear Box.
if we agree on the above now explain to me how the size of the tyre would influence the speed reading the sensor takes reading before the tyre?

Still describing how the speedometer works!

Starting from the last line, i have already explained in detail how tire size affects the speedometer. There is no new explanation that i have to give.

Speed sensor that you have just mentioned is actually what they use as ABS sensor and for vehicle stability assist. Each wheel hub of cars with ABS system has a speed sensor which functions as a speed comparison for all wheels, any wheel with a lower speed to the other wheels is regarded as a locked wheel and the ABS system kicks in. These sensors are not connected to speedometer.

The speedometer sensor has also replaced the drive by wire speedometer like you said. Unfortunately the location of the speed sensor in the transmission output is the same as before which means that the calibration still depends on the tire size. Like i mentioned before, unless a new sensor is developed that can measure the tire rotation, the speedometer will still and always depend on the tire size. That is why no matter new or old, all cars have a specific tire size recommendation which you are advice not to change.

adanny01:


I think I get sultaan's point. Although, he left calibration out.

The bigger the tire or rim diameter the higher the speed. That's where I agree with him.

However, vehicle transmistions are calibrated to be used with specific diameter of tires/rims for the speedometer to be accurate. Any change from factory sized tires and rims render the speedometer incorrect. In this case, the car with a larger sized tire than spec will be faster even though the car speedometer reads 120km/h. This is just an apparent speed not the real speed.

Driver A can claim he overtook driver B st the same apparent speed but their real speed isn't same. With real speed there is no way there will be an overtaking just like you explained

Perfect answer to the op, lalasticlala must reward you.

erico2k2:

what you said is true of Old cars old school,newer cars now use a speed sensor no cable or stuff.check this
Electronic speedometers work in a completely different way. Small magnets attached to the car's rotating drive shaft sweep past tiny magnetic sensors (either reed switches or Hall-effect sensors) positioned nearby. Each time the magnets pass the sensors, they generate a brief pulse of electric current. An electronic circuit counts how quickly the pulses arrive and converts this into a speed, displayed electronically on an LCD display. Since the circuit is measuring the number of wheel rotations, it can also keep a count of how far you've traveled, doubling-up as an odometer (distance-measuring meter). Electronic speedometers can also display speeds with analog pointers and dials, just like traditional eddy-current speedos: in that case, the electronic circuit drives a highly controllable electric motor (called a stepper motor) that rotates the pointer through an appropriate angle. Electronic speedometers are more reliable and compact than mechanical ones and the motion sensors can be any distance from the display that shows you your speed, making them suitable for any kind of vehicle ...
Im sure you must have heard of a Speed sensor,the speed is read by an ECU hence it can only be harked fru your OBD11 port.
That gear I showed in the picture is the Only calibration needed and its constant, I stand to be corrected, its either in teh axle or the output of your gear Box.
if we agree on the above now explain to me how the size of the tyre would influence the speed reading the sensor takes reading before the tyre?

I just thought of one last explanation.

For example, am engine also has a speed sensor which is translated as the tachometer which measures revolution per minute.

TheABS speed sensor does the same but in this case to activate ABS when one wheel stops.

The speed sensor in the transmission output also measure revolutions per minute. This cannot tell the speed of the car in km/h or MPH. In translating rev/min to km/h you need to know how many km movement of the car makes one revolution. In this case, the ecu is programmed that x revolutions covers y distance. Y distance is based on tire size so changing it conflicts ECU programming making speedometer wrong.

Beyond this I have no further.

adanny01:


I just thought of one last explanation.

For example, am engine also has a speed sensor which is translated as the tachometer which measures revolution per minute.

TheABS speed sensor does the same but in this case to activate ABS when one wheel stops.

The speed sensor in the transmission output also measure revolutions per minute. This cannot tell the speed of the car in km/h or MPH. In translating rev/min to km/h you need to know how many km movement of the car makes one revolution. In this case, the ecu is programmed that x revolutions covers y distance. Y distance is based on tire size so changing it conflicts ECU programming making speedometer wrong.

Beyond this I have no further.

one question for you.
Have you ever changed your speed sensor ?
Did you take your time to read what I just wrote?
How the speed sensor counts the teeth on the gear to calculate it's speed ?
That gear I showed in that pic is not of gear box output but that of the axle in the back . Nothing near the gear Box.

erico2k2:

one question for you.
Have you ever changed your speed sensor ?
Did you take your time to read what I just wrote?
How the speed sensor counts the teeth on the gear to calculate it's speed ?
That gear I showed in that pic is not of gear box output but that of the axle in the back . Nothing near the gear Box.

I haven't.

I did as a matter of fact.

Yes, this is where you have misunderstood. True, the speed sensor counts teeth. The speed it counts is not what you think it is and this where me and u diverge. Rev/min, km/h and mph are all units of speed. The speed at this level is revolutions/min( you may say raw format). The speedometer in your car doesn't say rev/min, does it? The ECU converts rev/min to km/h or mph. Coverting min to hr is very easy and taught in elementary schools. To convert revolutions to km/miles is the complicated one. This complicated one is the exercise I did for you on paper. Did you read it and the links i gave you? You would have to know how many revolutions make 1km/mile or how many km/mile makes 1 revolution. That relationship can't be known with out knowing the diameter of tire. Hence my conclusions.

If your speedometer were to read rev/min I would totally agree with you but it doesn't.

It really doesn't matter the exact position of the speed sensor, different manufacturers place it where it is convenient. The only sure thing is that it must be on the gear output be it axle, shaft, wheel hub or even CVT joints. All these locations will give you same result in revolutions/min.

Pls understand that we are on the same team (car talk), no victor no vanquished. I do not know every thing and am sure you don't know all either. One's knowledge may start from were the other stops. Let's not lose sight of the purpose of the thread.

ableguy:
Can a car going at the speed of for instance 120km/ph overtake another car doing the same speed? I have argued about this on several occasions, because I believe the speed clock or odometer should be like a clock that's always accurate and no clock goes faster than others.
I know car engine, horsepower and capabilities differ. But then I believe a car going at the same speed can't overtake the other.
If I am doing 120 km/hr for another car to overtake me it must be doing at least 125 or 130, car gurus in the house please help.

mumu question. Simple maths. None can overtake each other at the same speed. However, horsepower and torque differences can push a car faster than the other from 120km/h to higher km.

adanny01:


I haven't.

I did as a matter of fact.

Yes, this is where you have misunderstood. True, the speed sensor counts teeth. The speed it counts is not what you think it is and this where me and u diverge. Rev/min, km/h and mph are all units of speed. The speed at this level is revolutions/min( you may say raw format). The speedometer in your car doesn't say rev/min, does it? The ECU converts rev/min to km/h or mph. Coverting min to hr is very easy and taught in elementary schools. To convert revolutions to km/miles is the complicated one. This complicated one is the exercise I did for you on paper. Did you read it and the links i gave you? You would have to know how many revolutions make 1km/mile or how many km/mile makes 1 revolution. That relationship can't be known with out knowing the diameter of tire. Hence my conclusions.

If your speedometer were to read rev/min I would totally agree with you but it doesn't.

It really doesn't matter the exact position of the speed sensor, different manufacturers place it where it is convenient. The only sure thing is that it must be on the gear output be it axle, shaft, wheel hub or even CVT joints. All these locations will give you same result in revolutions/min.

Pls understand that we are on the same team (car talk), no victor no vanquished. I do not know every thing and am sure you don't know all either. One's knowledge may start from were the other stops. Let's not lose sight of the purpose of the thread.

OK you just got me up side down, rev/min is done by this http://www.carsdirect.com/car-repair/what-an-engine-speed-sensor-does
big diff between the two, I was talking about vehicle speed sensor that goes to your speedometer like this http://www.doityourself.com/stry/how-to-replace-a-vehicle-speed-sensor
Im only hamering on this cos I have personaly changed my own speed sensor when my pedometer stopped working, plus changed my ABS sensor as well so I have first hand info about this.Let us not forget what teh ABS sensors does so we dont add it into this mix.
One thing we must know is this Car A might get to 50km/h in 10 secs but car B might get to same 60km/hr in 4 secs. however when they get to same speed the will move at equal pace

watchworldpro:
mumu question. Simple maths. None can overtake each other at the same speed. However, horsepower and torque differences can push a car faster than the other from 120km/h to higher km.

U r correct but U 4 nor call teh guy mumu nah, it seems simple but yet hard to explain

The answer is yes. 120kph is 120 kph regardless if it's keke or Bugatti. If we are drag racing... both of us maxed out at 120kph... side by side down the last straight ....you are on the outside lane and I am in the inside lane... a left semi circle turn then the finish line... who will cross the line first? ...or would you try telling me we are going to cross at the same time? I rest my case.

Originalsly:
The answer is yes. 120kph is 120 kph regardless if it's keke or Bugatti. If we are drag racing... both of us maxed out at 120kph... side by side down the last straight ....you are on the outside lane and I am in the inside lane... a left semi circle turn then the finish line... who will cross the line first? ...or would you try telling me we are going to cross at the same time? I rest my case.

If you was i n a straight line

erico2k2:

OK you just got me up side down, rev/min is done by this http://www.carsdirect.com/car-repair/what-an-engine-speed-sensor-does
big diff between the two, I was talking about vehicle speed sensor that goes to your speedometer like this http://www.doityourself.com/stry/how-to-replace-a-vehicle-speed-sensor
Im only hamering on this cos I have personaly changed my own speed sensor when my pedometer stopped working, plus changed my ABS sensor as well so I have first hand info about this.Let us not forget what teh ABS sensors does so we dont add it into this mix.
One thing we must know is this Car A myight get to 50km/h in 10 secs but car B might get to same 60km/hr in 4 secs. however when they get to same speed the will move at equal pace

This thing is so simple I get frustrated trying to get you grasp the concept.

What is the difference between vehicle (transmission) speed sensor, engine speed sensor and ABS/VSA speed sensor?

No differences! They are all one and the same thing in principle. They all measure the same thing called rotation. They all measure rotation of different parts. One for tachometer, the next for speedometer and the last for ABS. They do the same thing and work exactly the same way.

The only difference is that that of tachometer is not changed in unit of measure but the one for speedometer needs calibration to change unit of measure from rotation to km/h or mph. How hard can that be?

These are not sensors that easily go bad to be replaced. In most cases it's their harness that gets broken or physical damage to it. Changing any speed sensor does not take 5mins which entails disconecting the connector and losing the usually 10mm bolt that holds it in place.

If you want to know if I ever did remove one, yes, i changed CPK (crank shaft position sensor) and ABS sensors. As a matter of fact, I worked on a friends 2010 accord 3 days ago with the scan below.

erico2k2:

yes Boss
check this would you say 120kg of steel weigh same as 120kg of cotton ? There lays ur answer.

so you are in essence saying that people change cars because of speed?

oweniwe:
^^ Na wa o

What's waa here?