HUD vs. Dashboard Speedometer Issue????? [Archive] - Cadillac XLR Forum: XLR and XLR-V Forums

: HUD vs. Dashboard Speedometer Issue?????

02-10-2004, 04:37 PM
I'm hoping a few of you can let me know if you are also seeing the issue I'm having in my XLR. I will state upfront that this is a very minor issue, but one I would like to have worked if it is unlike other XLRs.

Basically the question is, "During constant speed, does the analog dashboard speedometer match the digital speedometer on the HUD?". I understand that the dashboard speedometer is not really analog but only appears that way. That said, I'm very interested in your experiences at constant speeds (since the dashboard speedometer has some lag compared to the HUD's digits).

In my case, if I'm constantly going at 42MPH on the HUD speedometer, the dashboard will read 40MPH. This is fairly consistent at speeds greater than 10MPH.

Thanks for the help. Also, my apologies to anyone who hadn't noticed this before. Once you see it, you'll notice it all the time.

02-10-2004, 06:21 PM
Never noticed it before. Must be hard to watch both meters and the road! I'll try to watch in the future.

00 vette
02-10-2004, 07:28 PM
The same thing hapens on my '00 Vette with one extra - when the HUD reads 70, the speedo will read 68 and pushing the cruise set button will yield 71. The relationships are seldom the same, but you can count on three different answers. The question is - which one do you tell the officer you were doing when he pulls you over?

02-10-2004, 07:59 PM
Hi Folks,

I have paid attention to the two read outs and have found them to provide the exact same information. I have notice a very slight lag of the dash speedo and the HUD during acceleration, very slight.


02-11-2004, 10:02 AM
Thanks, I appreciate any and all info!

Yes, the best way to do the check is to be on an empty straight road and set the ACC for an easy-to-read speed (35,40,45,50, etc). Then it is relatively straight forward to compare the two numbers.

02-11-2004, 01:21 PM
I noticed the dash speedo is one or two mph lower than the HUD.

02-11-2004, 09:44 PM
Hi Gang,

I find this amazing in that I have checked the difference between the two displays, for different reasons at the time, in the same manner described by alk3997 and did not see any difference in read out except for a little lag during excelleration.


02-12-2004, 10:07 AM
Looks like some speedometers are more calibrated than others.

Of course the next question is how to adjust the dashboard speedometer. I've heard that there may not be a way, but I find that hard to believe since you would think there is a calibration mechanism.

02-12-2004, 05:34 PM
The variation is so small, it doesn't seem worth the trouble to make any adjustments. If there weren't double readouts, would anyone really care if the speedometer was 1 or 2 mph off? Who would even know?

02-13-2004, 01:45 AM

You make a very good point! A 2 or 3 MPH is well with in the tolerance level. And, if you didn't have two read outs you would never had known the difference.

We took our NM to the symphony this evening and I paid, again, particular attention to the two read outs and they proved out what I had repoted before, they match with some lag during acceleration.

Keep in mind that tire pressure have a great influence on speedometer read out and this has an additional affect on the two types of read outs, i.e., analog vs digital.

So, just enjoy this excellent vehicle and besides whoes looking at the dash when you can see the HUD.


02-24-2004, 02:40 PM
I was riding up the road the other day enjoying the day and recalled this issue. So I decided that the best way to emulate the problem in my car was to set the cruise control on and monitor what happens--with and without distance control.

It is a vaild issue in my case as well but I do agree that it is not worth messing with.

I would assume that we all will receive updates when we go in for a future service.

02-24-2004, 11:55 PM

Thank you for your conformation. And, keeping on enjoying your XLR!