Skip to main content
23 votes

Why is the speed of a motorcycle measured at the front wheel?

There are pros and cons of each, remember you can easily spin or lock up the rear wheel, and in fact the rear wheel may be far less often at the correct speed. So the decision on this stems from ...
Rory Alsop's user avatar
  • 18.6k
20 votes

RPMs too high on freeway?

The specs for this vehicle show that it has a 5-speed manual and that 5th gear is OD/Overdrive. According to the performance data here: The following table from that page lists the speed at 1000 rpm ...
jwh20's user avatar
  • 12.1k
13 votes
Accepted

Why is the speed of a motorcycle measured at the front wheel?

Its not a rule of thumb that the Speedometer is connected to the front wheel. There are many Suzukies and hondas in my country that have the speedometer connected to the rear wheel. As Rory stated, ...
Shobin P's user avatar
  • 8,936
13 votes

RPMs too high on freeway?

That is the excellent Mazda B3 engine. It will give you 300k service if you treat it nicely. It loves to rev. It does not like to lug. If you are at high power at low RPM (e.g. an RPM that feels ...
Harper - Reinstate Monica's user avatar
12 votes

Why is the speed of a motorcycle measured at the front wheel?

The front wheel is used in most cases with mechanical speedometers (though there are exceptions) because it's just easier (and probably cheaper) to couple the front wheel to the mechanism. ...
Jakub's user avatar
  • 581
9 votes
Accepted

Calculating actual speed of vehicle based on wheel size?

The only thing your car can sense is the number of turns of some part of the drive train. In the old days it was a gear right off the transmission, and today it's an electronic sensor in the ...
cdunn's user avatar
  • 9,296
7 votes
Accepted

Meaning of dashboard "Check Engine Light" on motorbike

That's the check engine light, or CEL - if it lights up, you have a problem with the engine and should stop and investigate it. If it's blinking, count the number of flashes, as this will indicate a ...
Nick C's user avatar
  • 28.8k
6 votes

Why is the speed of a motorcycle measured at the front wheel?

All of my competition cars have had speedos, some of which didn't work at all. I have never once been in a race and had time to take my eyes off what was happening around me to look at the dials. ...
Steve Matthews's user avatar
5 votes
Accepted

How is vehicle speed calculated?

If the ECU would calculate speed from RPM, how would it calculate speed when the car is in neutral or during shifting? The speed usually is derived from the RPM of the output shaft of the ...
sweber's user avatar
  • 7,057
5 votes
Accepted

Volvo XC90 8V AWD car speed to piston revolution speed ratio changed after repair

Yes, I'd take it back to the shop to see if there is something they missed. While 300 rpm at 60mph is not a huge difference, to me this is about the difference of when a lock up torque converter isn't ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
5 votes

Prius dash board completely off and engine does not shut down

Follow up 10/4/2017 Since the incident reported below, I had the car diagnosed by Toyota and, as expected, they recommend replacing the instrument display unit (5 weeks to get the part and ~$900 in ...
Kilauea Carlos's user avatar
4 votes
Accepted

Speedometer on Opel Corsa sometimes not reacting

Often times the speedo cable just needs lubrication. You can do this by disconnecting the speedo cable at the back of the speedometer and dropping some oil down the cable. Happens on Miata's all the ...
RDS_JAF's user avatar
  • 411
4 votes
Accepted

Prius dash board completely off and engine does not shut down

The symptoms point to a failed Combination Meter. Besides the speedometer, it also controls the power off button and the dashboard lights (except the check engine light). Apparently it can also be ...
Gabriel Diego's user avatar
4 votes
Accepted

2012 Ford Fiesta S speedometer calibration

UK type approval states that a speedometer may read with upto a 10% error provided that the speed shown is either true or over. A speedometer may not under read when a car is new. Most manufacturers ...
Steve Matthews's user avatar
4 votes

How is vehicle speed calculated?

Somewhere there is a signal that measures rotating speed on the driveline, downstream of the torque converter. It is typically somewhere inside the transmission housing. Because of how a torque ...
zipzit's user avatar
  • 6,559
3 votes

How is vehicle speed calculated?

The speedometer is generally connected somewhere after the gearbox eg the driveshaft. So in normal circumstances this is directly proportional to the angular velocity of the wheels, depending on the ...
Chris Johns's user avatar
  • 1,586
3 votes

Can a speedometer be inaccurate?

Firstly you need to determine whether your speedometer is accurate or not. Ask a friend to drive and hold different speeds in a car with an accurate speedometer and then pace behind that car to see ...
GdD's user avatar
  • 17k
3 votes

RPMs too high on freeway?

I got 3,000 rpm at 120 km/h on a Hyunday Grand i10, 1.2 lts engine (~5 lts/100km)
Candid Moe's user avatar
3 votes
Accepted

Jeep Wrangler's speedometer maximizes at 160 km/h, Toyota Sienna 180. Why are speedometers in smaller cars even higher?

It's a standard fitment as with many other parts. They use the same instrument cluster for the higher spec versions too. It reduces manufacturing costs by not having unique parts for every vehicle. On ...
Weather Vane's user avatar
  • 2,314
2 votes

Calculating actual speed of vehicle based on wheel size?

To calculate the actual speed you need: Transmission gear ratios Final drive ratio Tire diameter Engine RPM [tire diameter (in inches)] * [pi] * [1/(gear ratio * final drive ratio)] / [in/ft] / [ft/...
rpmerf's user avatar
  • 8,403
2 votes

Prius dash board completely off and engine does not shut down

There is a Service Advisory from Toyota on this. I got my combo meter replaced on the 2007 Prius at Toyota's expense. I think there is a time and mileage limit for that. If you are within the limits, ...
Joseph's user avatar
  • 21
2 votes

Sporadic speedometer, and performance lags when speedometer not engaged

The Vehicle Speed Sensor sends signal to the Instrument Cluster. You can check pin 2 (blue/white) on the B connector for signal from the VSS. If there is signal you need a new cluster. If not you ...
Ben's user avatar
  • 10.7k
2 votes

Prius dash board completely off and engine does not shut down

I took my car in to Toyota and it was a bad combo meter they had to hold my car until the new meter came in because the mileage on the car had to match the new meter. They told me it would be around ...
lkhana325's user avatar
2 votes

06 Hyundai Tiburon 2.7l Automatic Speedometer and Odometer Inoperative

Back probed the VSS and the input signal at the instrument cluster. Yellow = Pin 17 (signal) at the instrument cluster Green = Pin 3 (signal) at the VSS Red = Pin 2 (ground) at the VSS That ...
Ben's user avatar
  • 10.7k
2 votes

Why is the speed of a motorcycle measured at the front wheel?

Here's a thought: Most cars have rear-wheel drive. Therefore, in most cars, measuring speed from rotation of the front wheel(s) is more reliable because the front wheels should only be able to spin ...
PMar's user avatar
  • 21
2 votes

Why is the speed of a motorcycle measured at the front wheel?

The speedometer is placed in the location that performs adequately well and that costs the manufacturer the least amount of money, and therefore generates the most profit. Period.
zipzit's user avatar
  • 6,559
2 votes

How can I repair my scratched dash?

There are many remedies for polishing perspex/plexiglass. Some even mention using toothpaste. I think I would start with the finest possible polishing compound first and see if the scratch is ...
Evren Yurtesen's user avatar
2 votes

How can I repair my scratched dash?

My first suggestion would be to ask the Volvo dealership if the piece of perspex is available individually and at what price, you may find it is available. Failing that, I'd say something like ...
Steve Matthews's user avatar
2 votes

Are speedometer cables universal?

As far as I know, there are two main groups of speedometer cables... Mechanical Electronic The mechanical cable connects to a geared output of the transmission which then drives a mechanical ...
RubberStamp's user avatar
2 votes
Accepted

How to save time history of cars' performance parameters with or without OBD

The easiest and most accurate thing you can do is buy something like a Racelogic data logger as it's a piece of hardware that's specifically designed for the exact purpose you describe.
Steve Matthews's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible