My HUD has a slight difference also. If I set the cruise for 60 MPH the HUD will indicate 58 while the speedo indicates 60.

Digital Vs. analogue ?

 

Regardless, neither are accurate. GPS based speed is where it's at.

On the highway, I run a GPS speedometer display from my Garmin Novu 660. Because even in my new Suburban the analog speedo says I'm doing 75 mph, when my real actual speed is 72.7 mph.

I trust the GPS speed, because that is exactly what will show up on a cops radar gun. As for analog speedos and HUD speed readings, they are really just for reference. And, just shifting your head up/down/left/right is enough to read your speedo differently.

GPS!

 

Ten Foe,

 

Im with Patrick, Im 4 miles an hour off on hwy speeds.
Then again, Im rolling on dubs..lol Thats so Gangster. not. :thud:

 

Thanks for the quick responses guys.

 

MINE DOES THE SAME. READS ABOUT 1/2 MILE OFF OF EACH OTHER. GPS IS THE ACCURATE WAY.

 

Being digital the HUD is more accurate.

However little things can affect your speed reading. (ie: tire being low on air) HUD says 60MPH and you might be actually going like 58 MPH

 

I've heard that and same thing with wear on the tire and even if you run a different wheel/tire setup a close match can be 1% different which can effect your speed reading by a few MPH.

My HUD and GPS are about 1 MPH off from one another at 70.

 

I can't remember the last time I actually looked at the speedo...The HUD is awesome

 

I cant believe no one has pointed out the real problem... Corvettes are so fast you cause a rift in the space time continuum. The speedo is in the past. :laughing:

 

You're on to something there.

 

This actually brings up a good discussion topic.

If the two are different, which I have noticed in the two cars I have had with HUD, they do seem to be, then they must be driven by different measuring instruments. I only notice when I set the cruise control, were typically on the DIC and the needle it will show 72mph, but the HUD reads 70.

You would think for consistency's sake they would drive both the HUD and the needle from the same feed. Odd?

 

You would think for consistency's sake they would drive both the HUD and the needle from the same feed. Odd?

Speed is digitally encoded at the wheel. The speedometer is an analog representation of the computers reading. Therefor it is subject to analog errors and miscalibrations.

When you start your vette you will notice that the speed/tach will go over the full scale before dropping back down. This is the calibration and check process for the speedometer.

If your cruise control is off, then chances are you probably set the speed by the analog speedometer and not the HUD. Whenever I set mine by the HUD is stays right at the set speed.

 

The difference in speed readings isn't that much, I was just curious if there was any calibration to be done.