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 ...
- 12.1k
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 ...
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 ...
- 162k
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 ...
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 ...
- 7,057
5
votes
Why are good car speedometers so slow?
It's so that you can read it.
I worked in instrumentation for a number of years, and it is normal for an instrument to update a digital display twice a second, otherwise you'll only see a blur of ...
- 2,473
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 ...
- 6,569
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 ...
- 411
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 ...
- 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 ...
- 17.7k
3
votes
Are speedometers on race motorcycles accurate in corners?
The speedo will read incorrectly by the difference in the rolling radius.
However, if you are that far over in a curve you would be well advised to be watching where you are going and for road ...
- 34.7k
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)
- 31
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 ...
- 2,473
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 ...
- 21
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 ...
- 1,198
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 ...
- 23.4k
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, ...
- 21
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 ...
- 121
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.
- 23.4k
2
votes
Are speedometers on race motorcycles accurate in corners?
Short answer is yes and no. Not sure what you mean by exaggerated, but it shouldn't be by that much. On the other hand, speed reported by the wheels hardly ever are correct on racetrack; if you are ...
- 121
2
votes
97 Chevy Tahoe 4x4 - Speedometer is reading 10 mph fast and fuel consumption seem to be up
Your vehicle has a module called a VSSB (vehicle speed sensor buffer) or a DRAC (digital ratio adapter controller). This is a small circuit board inside a non-waterproof snap-shut case that's usually ...
- 8,518
2
votes
Why are good car speedometers so slow?
It can't be because car electronics are not capable of fast updates, so it must be a conscious decision.
Consider --
Suppose you have 6 cylinder car cruising along at just 2000 rpm. There's one or ...
- 8,518
1
vote
Are there any vehicles that use the onboard GPS to calibrate or adjust the speedometer?
I have a vague recollection of watching Clarkson driving a concept car, a 4x4, in the desert somewhere on an episode of Top Gear many years ago. I can't remember the manufacturer but have a sneaking ...
- 23.4k
1
vote
Are there any vehicles that use the onboard GPS to calibrate or adjust the speedometer?
in my experience you are correct, no manufacture that i have seen so far updates speedometer accuracy via GPS. it would be a good idea however, wheel speed sensors are fairly accurate but with tire ...
- 146
1
vote
Accepted
Are there any vehicles that use the onboard GPS to calibrate or adjust the speedometer?
that is a good idea, but in my experience no. the speedometer is usually driven by wheel speed sensors (newer vehicles) or mechanical cable driven by the transmission (older vehicles). depending on ...
- 146
1
vote
How would a speedometer work on a different engine conversion setup?
If it is just an engine conversion you are doing, then the original speedo should work fine, since the speedo drive/sensor comes off the gearbox or final drive.
If you are changing the gearbox and ...
- 25.5k
1
vote
Accepted
Where is the Ford Fiesta 2011 speed sensor located?
The speed sensor should be located on the outside of the transmission housing on the passenger side. Looks like this.
EDIT:
Also found a diagram to repair the DPS6 transmission. This is where the ...
- 101
1
vote
Accepted
Mazda 3 speedometer not functioning
I had forgotten about this for some time. I've been driving with a functioning speedo for some time now. Simply replaced the ABS sensor and got my speedo back. As a bonus I also got my power steering ...
- 21
1
vote
Mazda 3 speedometer not functioning
You have to remove the battery duct and cover and possibly the battery and tray to access it.
- 8,000
1
vote
2012 logan milege 107000 milege
First check what servicing has been done - also check if this record is correct...
You could give it a thorough service now to have a clear starting point and to find possible issues that you need to ...
- 34.7k
Only top scored, non community-wiki answers of a minimum length are eligible