Based on repeated Garmin Nuvi GPS readings over about 7,500 miles and and also as observed on repeated "YOUR SPEED" doppler radar readings, I've observed that the speedometer on my 2010 ES-350 consistently reads about 2 MPH fast, and I took the car to my dealer (JM Lexus in Margate, FL) with that complaint. While I enjoyed their terrific customer waiting area (seriously--it's great!), they looked into the problem and returned the car to me about 90 minutes later. The service advisor reported that a tech checked the speedometer with a "special" computer and did a road test and confirmed that the speedometer is performing perfectly with no error. They suggest that my GPS is off! (Yeah, right!)
Interestingly, on a trip to California I took the Garmin with me and used it in a Chevrolet rental car. The GPS speeds and Chevy speedometer speeds were identical.
Like other posters, I can live with the error because I get the correct speed on the Garmin. The Lexus approach to this does seem way "head-in-the-sand" to me!
Like the man said, your mileage may vary. Literally!
--MiltB
