Speedometer reading off compared to Waze?

[Spikeitaudi]

I have a Stock Premium and noticed that above 40MPH the speedo is about 1-2 mph faster than Waze. Above 68 it can get 2-3 MPH faster than Waze. Anybody else notice this and mention this to the dealer yet?

Thank you and Happy New Year!

 

[KAR120C]

That's within specs for all cars. As long as the speedo reads high it can run 5% higher. It just can't be lower than the actual speed. The error you're seeing is about what most of my cars show when I compare speedo vs. GPS.

 

[Spikeitaudi]

That's within specs for all cars. As long as the speedo reads high it can run 5% higher. It just can't be lower than the actual speed. The error you're seeing is about what most of my cars show when I compare speedo vs. GPS.

Thank you for your help. That is interesting though as none of my Hondas and my current Tesla have had any of those deviations in speed read out compared to Waze. Thank you again for the info.

 

[SethGX]

If it reads fast, then that means going up a tire size will actually make it more accurate since larger tires make it read slower.

 

[Spikeitaudi]

If it reads fast, then that means going up a tire size will actually make it more accurate since larger tires make it read slower.

It's weird though as again it read spot on up to 40MPH. Then after that it is off up to 2MPH till up to about 68 which then it is off by 2-3. You would think it would be consistently off?

 

[SethGX]

Nah, it's a linear discrepancy so the percent difference is the same all the way through. That means that up to 40 you can't tell because the percent difference isn't enough to notice, but at 100mph it could be 3-4mph off, or about 3-4%.

 

[Spikeitaudi]

Nah, it's a linear discrepancy so the percent difference is the same all the way through. That means that up to 40 you can't tell because the percent difference isn't enough to notice, but at 100mph it could be 3-4mph off, or about 3-4%.

Makes sense. Thank you!

 

[munkeeboi]

My guess is that they are all calibrated to the larger OT 33’ish tires. I have a premium + that had the same issue as you and when I upgraded to true 33” tires, the Speedo is actually slower by a tiny percentage. I’d prefer this as it is not accumulating “false” mileage on the ODO

 

[Spikeitaudi]

My guess is that they are all calibrated to the larger OT 33’ish tires. I have a premium + that had the same issue as you and when I upgraded to true 33” tires, the Speedo is actually slower by a tiny percentage. I’d prefer this as it is not accumulating “false” mileage on the ODO

That is my exact point with the false milage which it is reporting currently has it's showing faster right now. Don't like that.

 

[Toxicdog]

That is my exact point with the false milage which it is reporting currently has it's showing faster right now. Don't like that.

Have you manually calcualted your speed? My waze/google speeds are always off compared to my actual speed.

 

[Spikeitaudi]

Have you manually calcualted your speed? My waze/google speeds are always off compared to my actual speed.

No I have not but Waze has matched my other cars speedo pretty closely. This is the only car have noticed a plus 2 difference and sometimes plus 3.

 

[munkeeboi]

I used waze as well as calibrating with local radar signs while driving. Not perfect, but closest I can get short of asking a cop to help. lol

I think the false reading was also attributed to my high (per my self-recognized driving habits) 19.5-20 mpg computer reading in combined driving. When I changed to my new tires, I got closer to 17-17.5 combined, which I think is more true to life.

 

[Spikeitaudi]

I used waze as well as calibrating with local radar signs while driving. Not perfect, but closest I can get short of asking a cop to help. lol

I think the false reading was also attributed to my high (per my self-recognized driving habits) 19.5-20 mpg computer reading in combined driving. When I changed to my new tires, I got closer to 17-17.5 combined, which I think is more true to life.

You went with the Vossens right from the 20 inch with Yokohama's? How is the drive feel now? I wanted to stay with the stock 20 but just go bigger if possible.

 

[munkeeboi]

Vossen 20's with Toyo At3 275/65/20 (SL) ..weight is only about 3 lbs more per rim compared to the stock premium 20's.

You can tell the difference when going to AT Tires, nothing drastic, but it's all relative. It might be just in my head, but bumps seem way softer and cushioned due to the extra meat around the rim.

The 275/65 will work perfectly with the stock 20" rims.

 

[Danh63]

I know my BMW's speedo is 3mph faster than what I am going. Drives me nuts. I was wondering if my GX was the same