Adjust speedometer for different tire circumferences

[DaddyO]

Does anyone know if VCDS/OBD11 can be used to adjust the speedometer if tire sizes different than stock are fitted to the car?

[Audisthesia]

Tire circumference is found here, looks like 15 choices. Have fun.

https://i.ibb.co/0yPxxCJ/20220908-055327.jpg (https://ibb.co/CKxffb0)

[NewYorkS6]

Tire circumference is found here, looks like 15 choices. Have fun.

https://i.ibb.co/0yPxxCJ/20220908-055327.jpg (https://ibb.co/CKxffb0)

damn. still the man!!

[GilliamOS]

Tire circumference is found here, looks like 15 choices. Have fun.

Any documentation on which value each represents?

[Audisthesia]

Any documentation on which value each represents?

No, it can be deciphered, it’s been done for other VAG cars, but I have no interest in spending time on it. In my opinion it’s not worth the effort. It’s well known the Speedo over reports speed stock(intentionally so by VAG); and given most people do not significantly alter their tire circumference, they remain within acceptable variance.

I’d rather spend my time sorting out the custom PID for oil temp so I can have it display up on my Rsnav in split screen with torque.

[GilliamOS]

No, it can be deciphered, it’s been done for other VAG cars, but I have no interest in spending time on it. In my opinion it’s not worth the effort. It’s well known the Speedo over reports speed stock(intentionally so by VAG); and given most people do not significantly alter their tire circumference, they remain within acceptable variance.

I’d rather spend my time sorting out the custom PID for oil temp so I can have it display up on my Rsnav in split screen with torque.

Ah, def not worth the effort if it's not already done at this point.

[DaddyO]

No, it can be deciphered, it’s been done for other VAG cars, but I have no interest in spending time on it. In my opinion it’s not worth the effort. It’s well known the Speedo over reports speed stock(intentionally so by VAG); and given most people do not significantly alter their tire circumference, they remain within acceptable variance.

I’d rather spend my time sorting out the custom PID for oil temp so I can have it display up on my Rsnav in split screen with torque.

Interesting - so by going with a slightly larger wheel/tire diameter, it should make the speedo more accurate. LOL......gotta love those VAG engineers! As an aside, do you know why the VAG speedos over report speed? Just wondering....

[RPMtech147]

Interesting - so by going with a slightly larger wheel/tire diameter, it should make the speedo more accurate. LOL......gotta love those VAG engineers! As an aside, do you know why the VAG speedos over report speed? Just wondering....

Most cars read just a touch higher than actual speed...At least every car I've ever used GPS and compared it the cluster....So dozens of different makes and models.

[Audisthesia]

Interesting - so by going with a slightly larger wheel/tire diameter, it should make the speedo more accurate. LOL......gotta love those VAG engineers! As an aside, do you know why the VAG speedos over report speed? Just wondering....

Simple. So they don't get sued.

[Burkeomatic]

Sometimes it sucks living in a world where everything is designed to cater to the lowest common denominator. They haven't put accurate gauges in most vehicles for years, temp gauges, oil gauges... etc. I would love to have my speedometer accurate though, I may have to look into this. It always drives me nuts seeing my actual gps speed say 87 when my speedometer says 90.

[Audisthesia]

Sometimes it sucks living in a world where everything is designed to cater to the lowest common denominator. They haven't put accurate gauges in most vehicles for years, temp gauges, oil gauges... etc. I would love to have my speedometer accurate though, I may have to look into this. It always drives me nuts seeing my actual gps speed say 87 when my speedometer says 90.

Just wait until you compare the ECU speed to the cluster speed