Gravity Speedometer of off

[boydracing]

Saw some stuff on the Air back in 2024 for a speedometer error. I guess it is the same with the Gravity too. I go 30 mph and actual speed is 28 mph. I verified this on local RADAR in neighborhood as well as handheld GPS speed. I am a 21"/22" wheels Gravity. this would equate around 7% over the actual. Can Lucid fix this? I mean, obviously this should not be a big deal. It is a big deal when it comes to warranty life.

 

[fadooly]

Hi

Almost all manufacturers do this to avoid legal repercussions for speeding

 

[TahoeMichael]

Saw some stuff on the Air back in 2024 for a speedometer error. I guess it is the same with the Gravity too. I go 30 mph and actual speed is 28 mph. I verified this on local RADAR in neighborhood as well as handheld GPS speed. I am a 21"/22" wheels Gravity. this would equate around 7% over the actual. Can Lucid fix this? I mean, obviously this should not be a big deal. It is a big deal when it comes to warranty life.

Personally, I want my speedometer to be as accurate as possible. I hadn't thought about the discrepancy prematurely ending the warranty. Considering how expensive out-of-warranty repair costs probably are for a Gravity, that seems like plenty of reason to send the vehicle to a service center for correction.

 

[Leftlane]

The speedometer operates separately from the odometer so no worries about early warranty expiration. Also, every Porsche I’ve owned has read 3-4 mph faster than actual - always. My Tesla seems dead on with radar and GPS but it definitely is not uncommon for the speedo to read a little fast for a lot of cars.

 

[borski]

There are many threads on this. It is intentional, and the law allows for up to a 15% discrepancy iirc. Lots on the forum about this for the Air.

 

[boydracing]

There are many threads on this. It is intentional, and the law allows for up to a 15% discrepancy iirc. Lots on the forum about this for the Air.

So you are referring to 49 CFR §393.82? 15% is a pretty big sway from the national standard of 10% +/- at 50 mph. Oh, and yes, 7% is well within the national limits.

 

[borski]

So you are referring to 49 CFR §393.82? 15% is a pretty big sway from the national standard of 10% +/- at 50 mph. Oh, and yes, 7% is well within the national limits.

I did hedge with “if I recall correctly,” and apparently I didn’t. But that subsection of the code only applies to commercial vehicles (if I recall correctly, lol).

The other two relevant sources are:

• European Union (EU) Rules: Mandate that speedometers must never indicate a speed lower than the actual speed, allowing for some error on the higher side (e.g., up to 5% plus).
• Society of Automotive Engineers (SAE) Standard J1226: Recommends manufacturers calibrate for accuracy within 2% (plus/minus) or 4% with a bias towards reading high.

 

[boydracing]

I did hedge with “if I recall correctly,” and apparently I didn’t. But that subsection of the code only applies to commercial vehicles (if I recall correctly, lol).

The other two relevant sources are:

• European Union (EU) Rules: Mandate that speedometers must never indicate a speed lower than the actual speed, allowing for some error on the higher side (e.g., up to 5% plus).
• Society of Automotive Engineers (SAE) Standard J1226: Recommends manufacturers calibrate for accuracy within 2% (plus/minus) or 4% with a bias towards reading high.

...but it doesn't. YMMV

 

[doubletwist]

My 2025 AT reads 1mph slow at 70 (Relative to Waze. Car at 71, Waze reads 70)

My previous BMW was reading 3.5-4mph slow at 70mph, also relative to Waze reading.

 

[Leftlane]

My 2025 AT reads 1mph slow at 70 (Relative to Waze. Car at 71, Waze reads 70)

My previous BMW was reading 3.5-4mph slow at 70mph, also relative to Waze reading.

In that example, your car is actually reading slightly fast, not slow.

 

[doubletwist]

In that example, your car is actually reading slightly fast, not slow.

I never claimed to be good at math.

 

[boydracing]

I guess the standards say if your speedometer is accurate to within 5+/- mph @ 50 mph - GTG. Except for my Datsun Roadster, no other car I owned was off by more than 1 mph. I guess I was lucky. At least my example of the Gravity is accurate within 2 mph.

The 1969 Datsun Roadster was highly optimistic. If I was doing 70 mph - actual speed was more like 65 mph. I think that had to do with something I did.