Hi guys I owned fg mk2 from stock 18 inch I went to 20 inchs. Stock sizee 245/40/18 all around . I went 20 inchs 245/35/20 on front and 275/30/20 on rears. My ques is wats the speed diff at 100kph?? Thxx

Speedo error calculator – speedometer error as a result of tyre size change – Speedometer calibration

http://www.tyresizecalculator.com/tyre-wheel-calculators/speedo-error-calculator

3km/h

3km/h

thxx mate

can be corrected in tune

Can this be done to stock car or only a car with a SCT tune loaded already?

If you had a tune already; and then change tyres at a latter date....how long would it take you to access tune & correct speedo? Is it a 5-10min job?

ecu needs to be adjusted so it will take some form of software to access it to change it, only takes 15 minutes or so once the car is on the dyno

Awesome! I'm sure my tuner will charge bugger all for that then....

Thanks ratter!

Thxx ratter . U are always great help +1

Thanks and you're welcome