Yes - this was posted here on EcoModder a long time ago, and I have used it, and I think others have to.
https://www.instructables.com/id/Mea...t-of-your-car/
I used my phone to video tape the speedometer in KPH, and did the timing by watching the video later. This is much easier and safer and more accurate, than trying to do it while in the car.