Motor Vehicle Maintenance & Repair Stack Exchange
Motor Vehicle Maintenance & Repair Stack Exchange

Questions tagged [speedometer]

Instrument indicating the speed of a vehicle in km/h or mph

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

I have been thinking about this, from quite long ago. Why is speed always calculated from the front wheel? Let's just consider the following situation:- You are in a race, and you have given full throttle in 1st gear and you have ended up in a…
NANDAKUMAR THANGAVELU
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RPMs too high on freeway?

I just bought a 2006 kia rio sedan with a manual 5 speed transmission. During the test drive I couldn't go over 55mph (wasn't near any freeways) My first time on the freeway the rpms were around 3300 at 65 mph and the car sounded like it needed to…
Dexter74
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Speedometer on Opel Corsa sometimes not reacting

The speedometer needle on my Opel Corsa most of the time lies at the top of the scale (200) and doesn't move during driving. Sometimes, however, the needle rests at a different number, such as 140km/h and shows the speed accurately when driving,…
DK2AX
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Calculating actual speed of vehicle based on wheel size?

I started wondering today, how does one calculate the moving velocity of a vehicle if they change their tires? I know there are a lot of companies that make the gauges for tuners that change wheels, but what is the math involved in this? If for…
cloudnyn3
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Prius dash board completely off and engine does not shut down

I took my 2006 Prius on a trip and at some point I drove for about 15 miles in unpaved road. The road was not really bumpy but it vibrated the car a little. About 10 miles into the ride in the unpaved road, after I pulled over for a 1 hour stop, I…
Gabriel Diego
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How do nonlinear speedometers work?

Some cars, now have nonlinear speedometers. How can they achieve to get different spacing between some speed ranges? For better understanding, see the image of an old Audi A4 speedometer. The range from 70 to 100 is not linear, because there are…
sergiol
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Do I have to change my speedometer setting if I get larger tires?

I bought a jeep with very small tires (not sure the exact size). I recently bought a new pair of tires that are probably 2 or 3 inches larger radius. Do I have to update my jeep so the speed is calibrated for the larger circumference of the…
Sponge Bob
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Volvo XC90 8V AWD car speed to piston revolution speed ratio changed after repair

I have a 2007 Volvo XC90 V8 AWD. I noticed driving on a flat highway the 6'th gear the ratio of SUV speed in miles per hour to the piston revolution speed in thousand rotation per minute is 40, especially between 60mph and higher. Now after a repair…
Hans
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Meaning of dashboard "Check Engine Light" on motorbike

Please help me understand the meaning of this dashboard light shown in the picture. ABOUT BIKE SPECIFICATION What happen if it blinks RED ?
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Intermittently fluctuating/non-functioning speedometer in Volvo 940. Possible causes?

I have a 1992 Volvo 940. A few months ago, the speedometer started malfunctioning intermittently. Sometimes it would read correctly, other times the needle would wobble around, and sometimes it would read zero. It was more likely to misbehave at…
William Cline
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How does the speedometer on my dash actually work?

So pretty much everyone knows what a speedometer is, the thing on your dash that tells you how fast you are going, whether or not you're speeding, and what speed you have the cruise control set to (assuming you have that feature)! Whilst driving on…
Max Goodridge
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Does tire size and/or tread wear significantly affect speed and speedometer accuracy?

I've always heard that tread wear affects the speed of your vehicle; i.e. you technically are going faster with new tires than you are with old, worn tires, for a given indicated speed by the speedometer. If this is true, are speedometers calibrated…
JYelton
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is it normal for my car to accelerate on downhill when no gas is applied.

I find myself having to apply the break pedal everytime I go down an inclination. It's not too steep but the car seems to gain speed faster and faster. In the other cars I have driven, this was not the case. cars would maintain their speed without…
Kim Jong Woo
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VSS accuracy at low speeds

Background I recently got a P1500 code on my 98 Mazda 626 GF. I hooked up my computer using ForScan and cleared the code. It didn't come back after three slow test drives around the parking lot. Here is what the workshop manual says for a P1500…
Robert S. Barnes
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Excursion SuperDuty Cannot Calibrate Speedometer

I have an 02 Excursion Limited Diesel and cannot get the speedometer calibrated. I purchased the vehicle with 35" tires (original equipment is 32") The tires were about 75% worn and the speedometer was off by a consistent 5% at any speed (reading…
maplemale
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