Speedo calibration - is it possible?
07-27-2014, 06:22 PM
#16
Three Wheelin'
I believe that your mileage (odometer) is probably very accurate, calibrated at the factory based on your gearing and wheel/tire diameter. The reading of the speedometer is set by most factories to be optimistic and thus can be off while the mileage should be spot on.
03-07-2015, 01:07 PM
#18
Burning Brakes
Recently I've discovered that I have the same issue. My speedo and OBC both show speed to be 8% higher than the actual speed shown on a GPS/Speedo iPhone app.
I'm hoping that someone may still be able to provide some help or answers to this tread? And yes I've goggled and searched this forum and others without success.
I'm hoping that someone may still be able to provide some help or answers to this tread? And yes I've goggled and searched this forum and others without success.
03-07-2015, 05:09 PM
#19
Three Wheelin'
Recently I've discovered that I have the same issue. My speedo and OBC both show speed to be 8% higher than the actual speed shown on a GPS/Speedo iPhone app.
I'm hoping that someone may still be able to provide some help or answers to this tread? And yes I've goggled and searched this forum and others without success.
I'm hoping that someone may still be able to provide some help or answers to this tread? And yes I've goggled and searched this forum and others without success.
Follow the instructions in the write-up on fixing the odometer, it explains how to carefully remove the needle from the shaft.
03-08-2015, 11:28 PM
#21
Rennlist Member
Thread Starter
saw that this thread has been resurrected.... I can confirm it has nothing to do with wheel / tyre size. I am now running 18" wheels/tyres and my speedo is still the same amount out. In KM, it shows 50km when you are doing 45, 80km when you're doing 72 and 100km when you're doing 92.
I tried it with two different iphone 'speedometre' apps for accuracy (i am assuming that those are accurate).
It doesn't worry me greatly, now that I know how much it is out by - but still is kind of annoying.
I tried it with two different iphone 'speedometre' apps for accuracy (i am assuming that those are accurate).
It doesn't worry me greatly, now that I know how much it is out by - but still is kind of annoying.
03-08-2015, 11:56 PM
#22
Burning Brakes
hepkat,
Sounds like your cars reading about 8% higher as well. I also tried using a few different speedo apps and get the same result. The apps are based on GPS and also when I tried the app in my daily driver and my wife's car it was bang on. So app is accurate and so are the speedos in newer vehicles.
I know these cars are 25 years old, but Porsche is usually ahead of its time in technology, and for cars that are built for speed you'd expect that the speedo would be accurate. I'm starting to wonder if this is a more common issue with our cars. Maybe Porsche just wanted to make us think we're going faster than we actually are.
Like you I find it annoying and there must be a better fix for both the speedo and the OBC then just moving the needle.
Sounds like your cars reading about 8% higher as well. I also tried using a few different speedo apps and get the same result. The apps are based on GPS and also when I tried the app in my daily driver and my wife's car it was bang on. So app is accurate and so are the speedos in newer vehicles.
I know these cars are 25 years old, but Porsche is usually ahead of its time in technology, and for cars that are built for speed you'd expect that the speedo would be accurate. I'm starting to wonder if this is a more common issue with our cars. Maybe Porsche just wanted to make us think we're going faster than we actually are.
Like you I find it annoying and there must be a better fix for both the speedo and the OBC then just moving the needle.
03-09-2015, 05:04 PM
#23
Rennlist Member
Thread Starter
hepkat,
Sounds like your cars reading about 8% higher as well. I also tried using a few different speedo apps and get the same result. The apps are based on GPS and also when I tried the app in my daily driver and my wife's car it was bang on. So app is accurate and so are the speedos in newer vehicles.
I know these cars are 25 years old, but Porsche is usually ahead of its time in technology, and for cars that are built for speed you'd expect that the speedo would be accurate. I'm starting to wonder if this is a more common issue with our cars. Maybe Porsche just wanted to make us think we're going faster than we actually are.
Like you I find it annoying and there must be a better fix for both the speedo and the OBC then just moving the needle.
Sounds like your cars reading about 8% higher as well. I also tried using a few different speedo apps and get the same result. The apps are based on GPS and also when I tried the app in my daily driver and my wife's car it was bang on. So app is accurate and so are the speedos in newer vehicles.
I know these cars are 25 years old, but Porsche is usually ahead of its time in technology, and for cars that are built for speed you'd expect that the speedo would be accurate. I'm starting to wonder if this is a more common issue with our cars. Maybe Porsche just wanted to make us think we're going faster than we actually are.
Like you I find it annoying and there must be a better fix for both the speedo and the OBC then just moving the needle.
Ah - 1st world problems
03-09-2015, 06:07 PM
#24
http://www.autometer.com/media/manual/2650-1570-00.pdf
Autometer GPS speedo drive module, supposed to work with any electronic speedo.
Autometer GPS speedo drive module, supposed to work with any electronic speedo.
