Experience with OBD HUD Display Units

cooperdog on 06/12/2024 - 12:17
Last edited 06/12/2024 - 15:12 by 1 other user

Saw these and thought it looks a good way to get an accurate digital speedo as well as keeping a general eye on whats happening under the bonnet of my car.

https://www.amazon.com.au/wiiyii-Display-Speedometer-Compute…
https://www.amazon.com.au/wiiyii-Display-Smart-Gauge-Works/d…

Looks like they plug into the diagnostic (OBD) port found on nearly all cars.

I am leaning to the P10 model, although there are a variety of similar ones on Amazon, or about 40% cheaper on Aliexpress.

Any experience, hints, tips etc appreciated. The only concern I had was could it drain the battery, but I'd expect this would only be an issue if the car sat unused for an extended period.

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  MS Paint on 06/12/2024 - 12:50

  I run a Lufi XS on one of my cars to monitor and track data. The Lufi has an option to use GPS for speeds. It can be programmed to turn off when a condition is met (no rpm data for 3 seconds in my case) so it won't drain the battery.

  Your second link looks like a ripoff of the older model Lufi xf.

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  strawb on 06/12/2024 - 12:51

  -1

  I've had one similar to (but not the same as) the first one. Had it for about 5 years or more, and got it due to my Navara's speedo reading about 8% high. You can calibrate the HUD unit but it was accurate without any calibration. So the car's computer knew exactly how fast the car was going, but the speedo was displaying a higher number. I suspect the error was deliberate on the part of Nissan. TLDR - my experience to date with such units has been very positive

  • 

    GordonD on 06/12/2024 - 13:05

    -2

    the speedo was displaying a higher number. I suspect the error was deliberate

    I found out how far my speedo was reading high, and asked the dealer to correct it. I said what was the point of buying a performance version of a car, then having to drive around at significantly under the speed limit because the manufacturer had chosen to have it read high. The dealer said they could precisely calibrate the speedo, but the manufacturer wouldn't let them.

    There were a number of side effects of the speedo reading high. The fuel consumption appeared to be better than it actually was. Services were required more often. And the warranty ran out earlier. Once they told one lie, they had to make all the numbers tell the same lie to match.

    • 

      djsweet on 07/12/2024 - 10:58

      Just get it calibrated elsewhere? FWIW it shouldn’t affect the mileage. That would be calculated off the actual data going into the cluster assembly, not from the cluster itself (unless it’s pretty old).

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  Euphemistic on 06/12/2024 - 12:52

  I though a head up display was projected onto the windscreen? What do you need to see on the display? Regularly doing track days or towing heavy loads? Otherwise, not really needed.

  Plus, depending on your vehicle and where its mounted could count as obstructing view.

  • 

    bargaino on 06/12/2024 - 13:08

    Yes, these are not actually HUD units.
    But I guess something went wrong in translation to Chinese.

    I bought a GPS speedo from Aliex for less than $10, and it works. Dash-mount like this.
    Also an ODB2 dongle for diagnostics. What else do you want?

    • 

      pegaxs on 06/12/2024 - 13:52

      +2

      But I guess something went wrong in translation

      Oh, you want to come over to any of the Fartbook BYD forums… EVERYTHING that is in front of the driver is the "HUD". Dash cluster = HUD. Centre mounted monitor = HUD. Blind spot mirror indicators = HUD. Anything that is electronic and emits light towards the driver is a "HUD"… yet, ironically, the Seal does have an actual HUD… and most refer to that as the "windscreen projection" or "windscreen speedo".. This only thing that IS a HUD, is the only thing that isnt called the HUD…

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  GordonD on 06/12/2024 - 12:59

  Run GPS speedo app on phone. You quickly see how far out your car's speedo is or isn't. And go back to using it, without or with a small mental correction to what its reading.

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    Euphemistic on 06/12/2024 - 13:38

    This. I used a phone app and discovered my speedo reads 4km/h lower than actual between 50 and 90. Either side its slightly different. I now drive at 64, 74 etc knowing the actual speed is 60, 70 etc.

    Similar with old car, until I installed larger tyres amd the dial became accurate.

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  bobbified on 06/12/2024 - 13:24

  +1

  thought it looks a good way to get an accurate digital speedo

  If accurate speed is what you're after, a GPS unit would be much better. The OBD output will give you the same reading as what you currently get from your existing speedo (which could be displaying up to 10km/h over the speed you're actually travelling).

  • 

    Euphemistic on 06/12/2024 - 13:41

    The OBD output will give you the same reading as what you currently get from your existing speedo

    Not in all vehicles. The dial may be calibrated to show high in accordance with the standards, but the OBD data might be accurate. I had a car that would show accurate to calibration average speed (when reset on cruise control) while the speedo read higher.

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  apple2016 on 06/12/2024 - 15:50

  Saw these and thought it looks a good way to get an accurate digital speedo

  GPS receiver would be more accurate and reliable if you are only after accurate speed.

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  cooperdog on 06/12/2024 - 16:08

  I like the idea of being able to easily check engine characteristics, these also have alarms if stuff drops below thresholds too. Could be an early indication of an issue.

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    Euphemistic on 06/12/2024 - 16:21

    What are you going to check? I guess it's gonna be a toy you play with for a week then forget about - unless (as above) you tow heavy loads or go to track days regularly.