Speedo reading too low?

Hey folks, bought my mk8 st a few weeks ago and today was driving with Waze on for the first time. With cruise control set at 100km/h Waze was saying I was doing 111kmh. Kept an eye on it while driving around and Waze consistently read 8-12kmh higher than my Speedo. Is this just Waze being bad or has anyone had any experience with a mk8 speedo reading low. Don’t fancy getting done for speeding if I’ve been accidentally doing 10ish over everywhere I’ve been going.

Also noticed while on the motorway that I was catching everyone. Initally had my cruise control set to 110km/h but noticed I was having to pass more people than usual so thats when I pulled up Waze and it said I was doing 122km/h with the cruise set at 110km/h.

In many countries, cars can’t legally under-read, so manufacturers often design them to slightly over-read for safety and to protect themselves from liability. It’s kind of strange.

Exactly. It’s pretty strange for an app to say you’re going that much faster—it shouldn’t be possible. I drive an 8.5 ST, and my app (Flitsmeister, a Dutch app that avoids speed traps) is pretty much in line with my speedometer. My speedo is just slightly under.

Based on what you’re saying, it does sound like your speedometer is under-reading. Waze tends to be pretty accurate for me, and it sounds like your speed difference is pretty consistent.

That said, GPS isn’t always perfect—maybe get a friend to drive at 100kph and see what your speedo reads when you follow them.

The bigger question is why it’s under-reading in the first place. Could it be different wheels? But that seems like a significant difference just from changing wheels.

It’s strange that it’s under-reading, especially with the standard wheels. Since the car is still under warranty and your brother works at a Ford dealership, it might be worth taking it in to see what they say. You could also try using a few other GPS speed apps to make sure it’s not just a Waze issue, and maybe test with another phone to rule that out as well.

My 2012 is the opposite. When the needle shows 50 MPH, I’m actually going about 46-47 MPH.

Weird, mine’s the opposite. When my car’s speedo says I’m doing 30, for example, Waze usually shows around 28. It’s always about 1-2 MPH lower than what my speedo reads.