The 6 Best OBD2 Gauge Displays
Updated by · How we research
Some of these six OBD2 gauge displays need a 2008 or newer car. The top pick, the ScanGauge 3, works on most cars and light trucks from 1996 on. When users buy our independently chosen editorial selections, we may earn commissions to help fund the Wiki.
Not every gauge here works on every car: some need a 2008 or newer vehicle, while others cover most cars from 1996 on. Each one plugs into the diagnostic port under the dashboard and shows live data your instrument cluster leaves out, such as coolant temperature, boost, voltage or real-time fuel economy. Most also read and clear check-engine codes.
From the manual
- On a hybrid or stop-start car, change the sleep trigger from zero RPM; the other setting carries a small risk of draining the battery. p. 18
- Wait until it sleeps, about 12 seconds after shutoff, before unplugging it, or the trip data isn't saved. p. 7
- Firmware updates download over Wi-Fi, but only from a 2.4 GHz network. p. 19
- Above about 160°F the screen darkens, so on a sunny dashboard use a windshield shade or lift it off its magnetic mount. p. 10
Why the ScanGauge 3 is our top pick
The 3 and our runner-up, the ScanGauge II, both speak every OBD-II protocol, so they cover cars and light trucks back to 1996, and both carry a three-year warranty.1,3 What puts the 3 ahead is how little work its extra readings take, which matters most to anyone who tows.
Transmission temperature isn't a standard reading, so a gauge has to ask for it with a code that belongs to the carmaker. The 3 finds those codes itself: you pick your car's maker and it scans for the extra readings the car answers.1 On the II you type each code in by hand from the company's X-Gauge list, into one of 25 slots.3,5 The 3 also shows up to nine gauges at once on three saved pages, where the II shows four,1,3 and it can pop up an alarm with a sound when a reading crosses a limit you set.1
The II keeps one trick the 3's manual doesn't mention: a Performance Monitor that times 0-60 and quarter-mile runs.3 For a driver who wants fuel economy and four basic readings, the smaller II is the better value.
| ScanGauge 3 | ScanGauge II | |
|---|---|---|
| Extra factory readings | Scans for them by carmaker | Codes typed in by hand |
| Gauges on one screen | Up to 9 | 4 |
| Alarm at a set limit | On screen, with sound | Not in the manual |
| Display | Color touch screen | Backlit text, five buttons |
| Warranty | 3 years | 3 years |
Sources
- ScanGauge 3 1User manual, v1.21 (PDF), pp. 25, 28, 32, 41 2Product page
- ScanGauge II 3User manual, v6.0 (PDF), pp. 23, 38–41, 49, 60 4Product page
- 5ScanGauge X-Gauge command reference, 2026 (PDF)
From the manual
- Extra factory readings, such as transmission temperature, are typed in button by button from ScanGauge's code list; it stores up to 25. pp. 38-41
- Fuel figures need calibrating: fill to the pump's automatic shutoff twice and enter the gallons actually pumped at the second fill-up. pp. 20-21
- Set the fuel type to Hybrid on a hybrid, or it switches off whenever the engine stops. p. 12
- Its Performance Monitor times 0-60 and quarter-mile runs and saves up to eight of them. p. 49
Compare the specs
Swipe the table sideways to see every column.
| Product | Fits U.S. model years | Transmission temperature | Mounting | Warranty (years) |
|---|---|---|---|---|
| 1. ScanGauge 3 | 1996 and newer | Yes, X-Gauge auto-scan | Magnetic window mount | 3 |
| 2. ScanGauge II | 1996 and newer | Yes, codes entered by hand | Velcro strips | 3 |
| 3. Lufi XF | — | Some cars, via data files | Metal base, adhesive | — |
| 4. AEM X-Series OBDII Gauge | 2008 and newer (CAN only) | No | 52 mm hole or gauge pod | 1 |
| 5. Lufi X1 | — | CVT oil temp, some cars | Bracket, adhesive tape | 1 |
| 6. wiiyii P6 | 2008 and newer (OBD mode) | Listed as a reading | Bracket | — |
Model years are for U.S. vehicles, as the makers state them. A dash means the maker's manual and spec pages don't say. Readings beyond the standard set also depend on what the car sends.
Sources
From the manual
- If it stays on after shutdown, or cuts out when a hybrid's engine stops, Lufi says to wrap its ignition wire around a switched fuse. pp. 2-3
- Lufi rates its draw when shut down at under 1.5 milliamps. p. 4
- The warning lamp is sold separately; the gauge only has a port for it. p. 1
- If an update fails and the screen stays black, power it up while holding all three buttons to reach the update screen. p. 5
From the manual
- It can draw up to 20 milliamps while asleep, and AEM says to unplug it if the car will be stored for long periods. p. 2
- It sleeps once the engine stops, so on cars that clear codes only engine-off, start the car, then turn the key back to Run. pp. 3, 8
- It shows stored trouble codes, not pending ones, and it should be the only device plugged into the diagnostic port. p. 8
- It isn't waterproof, and water damage isn't covered by AEM's 12-month warranty. pp. 7, 9
From the manual
- Lufi rates its sleep draw at 1 milliamp or less, and it wakes by itself when the engine starts. pp. 1, 11
- Speed, revs, boost and fuel readings each have a calibration setting; Lufi notes that many dashboards show more than the true speed. p. 8
- A head-up mode flips the screen for windshield viewing, but Lufi says it looks weak in daylight without reflective film. p. 10
- The warning lamp is sold separately, and the one-year warranty doesn't cover damage you cause. pp. 1, 12
From the manual
- GPS is a separate mode you choose within five seconds of power-up; it can run from a USB cable when the car's port won't work. pp. 1, 5
- On hybrids and stop-start cars, set its shutoff mode to COM, or it switches off at every stop. p. 6
- Other plug-in devices, such as tire-pressure monitors or window modules, can make it freeze; unplug them first. p. 6
- The maker suggests unplugging it if the car will sit for more than a week. p. 4
Editor's Notes
November 3, 2026, by Ezvid Wiki Editors:
We read the makers' manuals for all six gauges and added a spec table, a section on why the ScanGauge 3 leads, and notes from each manual under its pick. We corrected the 2021 note's claim that most gauges read about 5 mph high on purpose; it's the dashboard speedometer that is usually set to read high. We also made clear that the wiiyii's GPS is a mode you switch to, not an automatic backup.
October 14, 2026, by Ezvid Wiki Editors:
The old top pick from 2021, the Ancel BD310, is now sold as a Bluetooth code reader rather than a gauge display, the UltraGauge and Autool X60 are currently unavailable, and we found no current listings for the VGEBY and Acecar picks. We dropped the Edge Insight because its Amazon listing is the discontinued CTS2 and many owners of the current CTS3 report screens that freeze.
We ranked the gauges on vehicle compatibility, what they can show, readability, reliability and value, using makers' manuals and specifications, trade-magazine and forum reports, and long-term owner feedback. No major car magazine has tested these devices, so we say where a claim is the maker's.
Earlier notes
February 26, 2021, by Kaivaan Kermani:
Note that most options do have a speed offset – that is they show a higher speed of about 5mph in most cases – in order to ‘encourage’ you to slow down. This is done in the interest of safety, but can obviously be adjusted. [2026 update: The gauges on today's list show the speed the car's computer reports. It's the dashboard speedometer that carmakers usually set to read a little high, and most of these gauges have a setting to correct their speed reading.]
I’ve removed options like the BlueDriver Professional and PLX Devices Kiwi 3, because I really feel like they belong in our list of the best obd2 scanners and not so much here. Of course, most gauges also offer diagnostics nowadays, but they’re definitely designed with the primary intention of displaying a gauge. OBD2 Gauges like the VGEBY Projector and Arestech A8 reflect onto the windscreen while most others are mounted options. Both have their unique advantages, though you may find the windscreen-reflected options take a little getting used to.
January 24, 2019, by Quincy Miller:
All of the options on this list should be fairly easy to install, as most are plug-and-play models. The primary decision users need to make is how they want to get the information — whether they want to read it off their phones, have it displayed on their windshield, or shown on the device itself. It's a personal decision, and one that should be made with your safety in mind. Whichever one is least likely to take your eyes off the road is probably best for you.
Special Honors
Banks iDash 1.8 Super Gauge For diesel pickups, the Banks iDash fits a standard 52-millimeter pod and can show more than 300 parameters on 2008 and newer vehicles, including exhaust gas temperature and boost, on a small color screen. It also reads and clears trouble codes and logs data to a memory card. bankspower.com
P3 Gauges V3 P3 builds digital gauges that replace an air vent in specific cars, including the Subaru WRX and BRZ, Honda Civic, and several VW, Audi, BMW and MINI models, so they look factory-installed. They show boost, oil and coolant temperature, air-fuel ratio, timing and more, with a shift light and inputs for extra sensors, for about $389 to $399. p3cars.com
Will An OBD2 Gauge Display Work With My Car?
Teslas don't offer standard OBD-II data, and other EVs share very little of it, though hybrids work.
Every car and light truck sold in the U.S. since 1996 has an OBD-II port, usually under the dashboard near the steering column. But the port speaks one of several protocols. Cars from 1996 through 2007 used a mix of older ones, and from 2008 every U.S. car had to use the newer CAN protocol (Wikipedia). Gauges that only speak CAN, like the Lufi and AEM models here, won't work on most cars older than 2008. The ScanGauges support every protocol, and ScanGauge publishes a compatibility list.
What a gauge can show also depends on the car. The standard readings, like RPM, speed, coolant temperature, intake temperature and engine load, are available on almost everything. Oil temperature has a standard code, but not every car sends it. Transmission temperature isn't part of the standard: each maker defines its own code for it (OBDLink), so only gauges that support manufacturer-specific readings can show it. ScanGauge publishes those codes for many makes (X-Gauge reference), and the ScanGauge 3 can scan for them itself. Lufi offers data files that add it on some cars (Lufi's site).
Electric cars are mostly out. Teslas don't offer standard OBD-II data, and other EVs share very little of it, though hybrids work.
Dash Gauge, Pod Or Head-Up Display?
Dash displays like the Lufis and ScanGauges sit on top of the dashboard on a stand, suction cup or tape. They show the most information and are easy to move between cars. Pod gauges like the AEM fit a standard 52-millimeter round gauge pod on the pillar or steering column, which looks the most factory-installed but shows one reading at a time.
Head-up displays project speed and a few readings onto the windshield. They're cheap and keep your eyes up, but they wash out in bright sun, and in a Tom's Guide review of a popular model the unit itself sat in the driver's view. State rules on what you can mount on a windshield vary, so a dash mount below the windshield is the safest choice.
Speed readings come from the car's own speed sensor, the same source as your speedometer. Carmakers usually set the speedometer to read a little high so it never shows less than your true speed (Wikipedia), which means a gauge and the dash can disagree by a few percent. Oversized tires throw both off. The ScanGauges, the Lufi X1 and the wiiyii let you correct the speed; the ScanGauge manual suggests matching a GPS in 1 percent steps.
Will It Drain My Battery?
A gauge that stays plugged in draws a little current whenever it's awake. Good ones sleep within seconds of the engine shutting off: the ScanGauge turns itself off about 12 seconds after the engine stops (ScanGauge manual), and Lufi rates the X1 at 1 milliamp or less asleep. AEM says its gauge can draw up to 20 milliamps asleep and should be unplugged for long storage (AEM instructions). Problems come when a gauge doesn't recognize that the car is off. ScanGauge warns that hybrids and cars with stop-start need a different sleep setting, and some Chrysler, Dodge and Jeep models confuse it.
If a car will sit for more than a week, unplugging the gauge is cheap insurance. The same goes for Bluetooth dongles, which some owners have found drain a battery over a month of storage.
If you'd rather use your phone as the display, a Bluetooth adapter such as the OBDLink MX+ with an app like Torque or OBD Fusion can show the same data. You give up an always-on screen, and you need a phone mount.
How we researched this
We compared more than 30 OBD2 gauge and head-up display listings and read a manual for each of the six picks: Linear Logic's ScanGauge 3 manual (v1.21) and ScanGaugeII manual 6.0, AEM's 30-0311 instructions, Lufi's English manuals for the XF and the X1 Revolution, and the P6 manual for the wiiyii. ScanGauge's 2026 X-Gauge command reference, the makers' product pages, a Tom's Guide head-up display review and Diesel World's Edge Insight install filled in the rest, along with enthusiast forum reports. Searches of the CPSC recall database and Health Canada's recall site found no recalls for ScanGauge, AEM, Lufi or wiiyii products.
Sources (21)
- ScanGauge 3 product page
- ScanGauge 3 manual v1.21
- ScanGauge II product page
- ScanGaugeII user manual v6.0
- ScanGauge X-Gauge command reference (2026)
- ScanGauge FAQs
- ScanGauge compatibility
- AEM 30-0311 instructions
- AEM X-Series OBDII gauge kit (30-0311) product page
- Lufi XF English user manual
- Lufi X1 English user manual
- Lufi custom data downloads
- wiiyii P6 user manual
- Tom's Guide: Dagood A8 head-up display review (2022)
- Diesel World: Edge Insight CTS3 install
- OBDLink: displaying transmission temperature
- OBDLink MX+
- Wikipedia: On-board diagnostics
- RV PRO: Banks iDash 1.8 Super Gauge
- CPSC recalls
- Wikipedia: Speedometer
Frequently asked questions
What does an OBD2 gauge display do?
It plugs into your car's diagnostic port and shows live engine data, such as coolant temperature, boost, voltage and fuel economy. Most also read and clear check-engine codes.
Will an OBD2 gauge work on my older car?
Every U.S. car from 1996 on has the port, but many gauges only support the protocol used from 2008 on. The ScanGauge 3 and ScanGauge II support all of them.
Can an OBD2 gauge show transmission temperature?
Only if it supports manufacturer-specific readings, because transmission temperature isn't a standard OBD-II reading. The ScanGauges can on many makes, the Lufis on some, and the AEM can't.
Can I leave an OBD2 gauge plugged in?
Usually, if it sleeps when the car is off. The ScanGauge sleeps about 12 seconds after shutoff. Unplug it if the car will sit for more than a week.
Do OBD2 gauges work on electric cars?
Mostly not. Teslas don't offer standard OBD-II data, and other EVs share very little. Hybrids do work.
Is a head-up display legal?
There's no federal ban, but states limit what can be mounted on a windshield. A dash mount below the windshield avoids the question.
